RVD260 district heating controller for 2 heating circuits and d.h.w. Basic Documentation Edition 2.
Published by: Siemens Switzerland Ltd. Building Technologies Division International Headquarters Theilerstrasse 1a CH-6300 Zug Switzerland Tel. +41 58-724 24 24 © Siemens Switzerland Ltd 2010 Delivery and technical specifications subject to change www.siemens.
Contents 1 Summary ....................................................................................................... 13 1.1 Glossary ........................................................................................................ 13 1.2 Brief description and key features ................................................................. 14 1.3 Type summary ............................................................................................... 14 1.4 Equipment combinations .....
.5.2 Types of sensors............................................................................................25 4.5.3 Error handling ................................................................................................25 4.6 D.h.w. storage tank temperature (B31, B32) .................................................26 4.6.1 Acquisition of measured value .......................................................................26 4.6.2 Type of sensor ....................................
10 Function: Display of faults ............................................................................. 35 10.1 Operating line ................................................................................................ 35 10.2 Display of faults ............................................................................................. 35 11 Function block: Plant configuration................................................................ 36 11.1 Operating lines ........................
12.10.4 Room model temperature ..............................................................................52 12.10.5 Optimum stop control .....................................................................................53 12.10.6 Quick setback ................................................................................................53 12.10.7 Optimum start control.....................................................................................53 12.10.
15.6.4 No priority ...................................................................................................... 64 15.7 Pump overrun ................................................................................................ 65 15.7.1 General .......................................................................................................... 65 15.7.2 Intermediate circuit pump .............................................................................. 65 15.7.
17 Function block: Assignment of d.h.w. ............................................................77 17.1 Operating line.................................................................................................77 17.2 Assignment d.h.w. charging ...........................................................................77 18 Function block: Extra legionella functions ......................................................78 18.1 Operating lines ...............................................
21.4.2 Direct d.h.w. heating via heat exchanger ...................................................... 88 21.5 Changeover winter-/summertime .................................................................. 89 21.6 Pump kick ...................................................................................................... 89 21.7 Speed-controlled pump ................................................................................. 89 22 Function block: M-bus parameters .......................
25.3.9 Maximum limitation of storage tank temperature .........................................101 25.3.10 Collector start function .................................................................................102 26 Function block: Refill functions ....................................................................103 26.1 Operating lines .............................................................................................103 26.2 General ...............................................
30.1 General ........................................................................................................ 114 30.2 Combination with room unit QAA50.110/101 .............................................. 114 30.2.1 General ........................................................................................................ 114 30.2.2 Overriding the operating mode .................................................................... 115 30.2.3 Knob for room temperature readjustments ...
33.3 Dimensions ..................................................................................................128 34 Addendum....................................................................................................129 34.1 Technical data..............................................................................................129 34.2 Revision history............................................................................................129 34.3 Index .........................
1 Summary 1.1 Glossary In this Basic Documentation, the following key terms are used (among others): Heat source, heat generation Term Explanation Heat exchanger Heat exchanger whose primary side is connected to the district heating network and whose secondary side supplies the heat to a precontrolled or common flow, or directly to the consumers, such as space heating, d.h.w. heating, etc.
1.2 Brief description and key features • The RVD260 is a multifunctional heating controller which has been designed to control the flow temperature of 2 heating circuits plus d.h.w. heating • The controller is used exclusively in plants with district heat connection. It is intended for use in small to medium-size residential and non-residential buildings with 2 heating circuits • A number of combinations facilitate the configuration of 14 different plant types.
1.4 Equipment combinations 1.4.1 Suitable sensors • For water temperatures: Suitable are all types of Siemens sensors using a sensing element LG-Ni1000: − Strapon sensor QAD22 − Immersion sensors QAE212... − Immersion sensor QAP21.3 complete with connecting cable − Immersion sensor QAP21.2 complete with connecting cable (solar) • For the room temperature: Suitable are PPS-compatible sensors: − Room units QAA50.
1.5 Product documentation Type of document Document no. Data Sheet N2515 Stock no.
2 Use 2.1 Types of plant The RVD260 is suited for all types of heating plants in houses or buildings… • connected to a district heating network and operating with 2 heating circuits, • in which the flow temperature of the heating circuits is controlled either weatheror room temperature-compensated, • where the control of d.h.w. heating is integrated as an option. 2.
• • • • • • • Reception of heat demand signal Limitation of return temperature differential (DRT function) Maximum limitation of primary return temperature Limitation of output or volumetric flow by pulses Suppression of hydraulic creep in the primary circuit Weather-compensated raising of the reduced room temperature setpoint Remote control via room unit 2.5 D.h.w. functions The RVD260 is used if 1 or several of the following d.h.w.
2.
3 Basics 3.1 Key technical features The RVD260 offers 3 key technical features: • The controller provides a total of 14 preprogrammed plant types. For details, refer to chapter 3.2 "Plant types", which shows the plants in the form of diagrams • The functions are assigned to 3 setting levels; setting levels "Heating engineer" and "Locking functions" have them summarized as function blocks • The settings are made via operating lines (see chapter 5 ff.
Plant types 1 - x 21/134 Siemens Building Technologies Basic Documentation RVD260 3 Basics CE1P2515en 2018-04-30
Plant types 2 - x Plant types 3 - x Plant types 4 - x 22/134 Siemens Building Technologies Basic Documentation RVD260 3 Basics CE1P2515en 2018-04-30
3.3 Operating modes 3.3.
4 Acquisition of measured values 4.1 General Should a sensor become faulty, the RVD260 tries to maintain the required comfort level. In that case, certain heat losses may occur, without causing any damage. In the event of severe errors, an error message is delivered and the controller displays Er (error). 4.2 Flow temperature (B1, B12, B3) 4.2.1 Types of sensors Suitable are all types of Siemens sensors using a sensing element LG-Ni1000. 4.2.
4.4 Room temperature (A6) 4.4.1 Types of sensors The room temperature is acquired via a PPS (point-to-point interface). The device connected to the PPS must deliver a suitable output signal. The measuring range is 0...32 °C. Suitable types of devices are: • Room unit QAA50.110/101 • Room unit QAW70 Note: If a room unit or room sensor is used in both heating circuits, 1 of the 2 devices must be addressable. This means: • The first room unit can be a QAA50.
4.6 D.h.w. storage tank temperature (B31, B32) 4.6.1 Acquisition of measured value The storage tank temperature is acquired via input B31. Depending on the type of plant, a second storage tank sensor is connected to input B32. 4.6.2 Type of sensor 1 or 2 sensors with LG-Ni1000 sensing element can be used. Thermostats cannot be used. 4.6.3 Error handling The controller’s response to errors in the measuring circuits depends on the way the d.h.w.
4.8 Return temperature (B7, B71, B72) 4.8.1 Acquisition of measured value Depending on the type of plant, the return temperature (primary and secondary) is acquired via inputs B7, B71 and B72. With plant types 2–x and 3–x, the primary return temperature acquired by B7 is forwarded via LPB. 4.8.2 Type of sensor Suitable are all types of Siemens sensors using a sensing element LG-Ni1000. 4.8.
4.10 Pressure sensors (U1, U2) 4.10.1 Acquisition of measured value The primary and secondary plant pressure for the refill function can be acquired via inputs U1 and U2. 4.10.2 Type of sensor Suitable are sensors delivering DC 0…10 V signals. The resulting pressure values for 0 V and 10 V can be set (refer to chapter 26.3.9 "Configuration of sensors"). 4.10.3 Error handling If the sensor acquires a pressure below 0.
5 Function: Space heating 5.1 Operating lines The "Space heating" function provides settings and displays for the end-user. The buttons for selecting the operating lines and for changing settings are described in chapter 31.1 "Operation". Line 1 2 3 5 6 7 8 9 10 11 12 5.
The setpoints for the nominal temperature and the reduced temperature plus that for frost protection are to be entered directly in °C room temperature. They always apply, independent of whether or not the control uses a room sensor. Without room sensor, the heating curve or the room model is taken into consideration. 5.3 Heating program The heating program of the RVD260 provides a maximum of 3 heating periods per day; also, every weekday can have different heating periods.
6 Function: Setting the clock 6.1 Operating lines Function "Setting the clock" function provides settings and displays for the end-user. Line 13 14 15 16 6.2 Function, parameter Time of day Weekday Date Year Factory setting (range) (00:00…23:59) Display function (01.01…31.12) (2009…2099) Unit hh:min d dd.mm yyyy Entries The RVD260 has a yearly clock with the time of day, the weekday and the date.
7 Function: D.h.w. 7.1 Operating lines The "D.h.w." function provides settings and displays for the end-user. Line 17 18 19 20 21 22 23 41 42 7.2 Function, parameter Weekday for entering the d.h.w. program Release period 1 start Release period 1 end Release period 2 start Release period 2 end Release period 3 start Release period 3 end Nominal d.h.w. setpoint Reduced d.h.w.
8 Function: Display of sensor values 8.1 Operating lines Function "Display of sensor values" provides displays for the end-user. Line 24 25 26 27 Function, parameter Room temperature Outside temperature D.h.w. temperature Flow temp. heating circuit 8.
9 Function: Holiday settings 9.1 Operating lines Function "Holiday settings" provides settings for the end-user. Line 31 32 33 9.2 Function, parameter Holiday period Date of first day of holiday period Date of last day of holiday period Factory setting (range) 1 (1…8) --.-- (--.--/01.01…31.12) --.-- (--.--/01.01…31.12) Unit dd.mm dd.mm Holiday program A maximum of 8 holiday periods per year can be programmed.
10 Function: Display of faults 10.1 Operating line Function "Display of faults" provides displays for the end-user. Line 50 Function, parameter Faults 10.
11 Function block: Plant configuration 11.1 Operating lines Function block "Plant configuration" provides settings for the heating engineer.
• Setting 3: B71/U1 acts as a scalable DC 0…10 V input to receive the heat demand from other devices • Setting 4: The connected sensor is used as a secondary pressure sensor for the refill function. For details of the refill function, refer to chapter 26 "Function block: Refill functions" 11.2.3 Input B7/U2 The function of input (terminal) B7/U2 is to be selected on operating line 53.
11.2.6 Input H5 The setting choices for input (terminal) H5 on operating line 56 are the following: 0 = no function 1 = reception of pulses: with plant type 1-x, the mode of operation of the pulse input is to be selected on operating line 57: 1 = only acting on heating circuit 1 2 = only acting on heating circuit 2 3 = acting on both heating circuits With the other plant types, the function always acts on 2-port valve Y1 in the primary return.
should be done by reducing the maximum pump speed since this saves pumping power. If the pump is allowed to operate at its rated capacity, the maximum speed is maintained at 100%. The setting range reaches from the value set on operating line 147 to 100% Control of heating circuit pump The following graph shows the control of the heating circuit pump. It shows the pump speed and the flow and return temperatures as a function of the outside temperature.
• With this kind of plant design, it is assumed that the outside temperature hardly ever drops below -5 °C. But during heating up processes, the pump speed is also increased above the minimum speed whenever the outside temperature lies above -5 °C Lower pump speeds mean: • Energy savings due to reduced pumping power • Greater differential of heating flow and return temperature • Lower return temperatures The heating circuit is controlled based on the signal received from the heating circuit’s flow sensor.
Control of storage tank charging pump The d.h.w. flow temperature setpoint should be maintained as accurately as possible, allowing the storage tank to be fully charged in one go. At the beginning of d.h.w. heating, the storage tank charging pump starts at minimum speed until the d.h.w. flow temperature setpoint is reached. Then, the speed is continuously increased. During charging, the storage tank charging pump reduces its speed only if sufficient heat is not available.
12 Function block: Space heating 12.1 Operating lines Function block "Space heating" provides settings for the heating engineer.
TA 25 TA 20 TAD 15 TAM 10 5 0 Progression of current, composite and attenuated outside temperature TA TAD TAM t t Current outside temperature Attenuated outside temperature Composite outside temperature Zeit 12.2.
2510D06 Impact of room temperature setpoint change on the flow temperature setpoint ∆wR Change of room temperature setpoint s Heating curve slope ∆wVT Change of flow temperature setpoint The flow temperature setpoint change ∆wVT is calculated according to the following formula: ∆wVT = ∆wR × ( s + 1 ) 12.
Each heating curve has a substitute line which intersects the pivotal point and ”its” heating curve at an outside temperature of 0 °C. Its slope is set on the controller and is calculated as follows: ∆TV ∆TAM s= The use of a substitute line is required because the heating curve is slightly deflected. This is necessary to compensate for the nonlinear radiation characteristics of the different types of radiators.
12.4.3 Setpoint for room temperature-compensated control 2513B02 The setpoint is generated based on the deviation of the current room temperature from the setpoint. In addition, the heating curve at a fixed outside temperature of 0 °C is taken into consideration.
12.4.4 Setpoint for weather-compensated control with room influence 2513B03 Here, heating curve and room influence act on the flow temperature setpoint – in addition to the outside temperature and the room temperature setpoint.
12.6 Heating circuit control The 2 heating circuits are controlled separately. 12.6.1 Weather-compensated control Prerequisites for this type of control: • Outside sensor connected • No room unit connected or, if connected, room influence set to 0 (minimum) The compensating variable for weather-compensated control is the composite outside temperature. Assignment of the flow temperature setpoint to the compensating variable is made via the adjusted heating curve.
The flow temperature setpoint is continuously shifted via the heating curve by the composite outside temperature. In addition, any deviation of the current room temperature from the setpoint leads to an immediate parallel displacement of the heating curve. The correlation between the deviation and the extent of the displacement is defined by the room influence.
The thermal inertia of the house or building in the case of outside temperature variations is taken into account by including the composite outside temperature in the automatic ECO function. 12.7.3 Heating limit The automatic ECO function necessitates a heating limit. An ECO temperature in the range –10...10 K can be set separately for each heating circuit (operating line 61). This setting value and the room temperature setpoint are used to calculate the heating limit.
12.10 Optimization 12.10.1 Definition and purpose Operation of the heating system is optimized. EN 12 098 defines optimization as the "automatic shifting of the switch-on and switch-off points aimed at saving energy". This means that… • switching on and heating up as well as switching off are controlled such that during building occupancy times the required room temperature level is always ensured, • the smallest possible amounts of energy are used to achieve this objective.
2513D04 12.10.3 Process 0.5 °C HP TR t t1 t2 t3 TRw TRw TRw TRx Heating program Room temperature Time Forward shift for early shutdown Forward shift to start heating up Quick setback Room temperature setpoint Nominal room temperature setpoint Reduced room temperature setpoint Actual value of room temperature 12.10.
12.10.5 Optimum stop control During occupancy times, the RVD260 maintains the setpoint for NORMAL heating. Toward the end of the occupancy time, the control system switches to the setpoint for REDUCED heating. Optimization calculates the switchover time such that, at the end of the occupancy time, the room temperature will lie 0.5 °C below the setpoint for NORMAL heating (early shutdown). When entering 0 hours for maximum early shutdown, optimum stop control is deactivated. 12.10.
12.10.8 Maximum rate of flow temperature increase Function TVw TVw ∆TVw ∆t 2522D07 t Maximum increase: t t ∆t TVw ∆TVw Time Unit of time Flow temperature setpoint Setpoint increase per unit of time For each heating circuit, the rate of increase of the flow temperature setpoint can be separately limited to a maximum (“heating up brake”). In that case, the maximum rate of increase of the flow temperature setpoint is the set temperature per unit of time (°C/hour).
12.11.3 Mode of operation without room sensor The controller continually determines the room temperature as a function of the flow temperature. If the room temperature falls below the adjusted setpoint for frost protection, the controller activates the heating circuit pump and controls the flow temperature such that the room temperature will lie by the switching differential of 1 K above that setpoint. Prerequisite is that the heating curve slope is correctly set.
12.12.4 Pump and mixing valve overrun If, during overrun, there is a sudden drop in the demand for heat, the consumer/heat exchanger generates a forced signal to avoid the accumulation of heat. In segment 0, the forced signal is forwarded to all devices in all segments; in segments 1...14, to all devices contained in the relevant segment. During overrun, consumers (heating circuits, d.h.w.
13 Function block: Valve actuator heat exchanger 13.1 Operating lines Function block "Valve actuator heat exchanger" provides settings for the heating engineer.
13.5 Minimum limitation of flow temperature The minimum limit value is to be set on operating line 86. The setting range for the minimum limit value reaches from 8 °C to the maximum limit (setting on operating line 85). At the limit value, the heating curve runs horizontally. This means that the flow temperature setpoint cannot fall below the minimum value. This function can be deactivated (entry of --- on operating line 86). 13.
14 Function block: Valve actuator space heating 14.1 Operating lines Function block "Valve actuator space heating" provides settings for the heating engineer. Line 91 92 93 94 95 96 Function, parameter Actuator running time heating circuit P-band heating circuit control Integral action time heating circuit control Setpoint boost mixing valve/heat exchanger Maximum limitation flow temperature Minimum limitation flow temperature 14.
14.5 Minimum limitation of flow temperature The minimum limit value is to be set on operating line 96. The setting range for the minimum limit value reaches from 8 °C to the maximum limit (setting on operating line 95). The function can be deactivated (entry of --- on operating line 96). At the limit value, the heating curve runs horizontally. This means that the flow temperature setpoint cannot fall below the minimum value.
15 Function block: D.h.w. heating/legionella function This function block contains all settings required for the general d.h.w. functions. Not included here and described in separate function blocks are: • The d.h.w. setpoints: Can be set by the end-user on operating lines 41 and 42 • Parameters for control of the actuators • Parameters on the locking functions level • Parameters for d.h.w. heating via solar collector or electric immersion heater The details of the different types of d.h.w.
• In the case of direct d.h.w. heating via heat exchanger, operating line 109 is deactivated • The release of d.h.w. charging is not dependent on the operating level of space heating 15.3 Control of circulating pump The function block controls a circulating pump, if installed. The pump is optional, irrespective of the type of plant. Operation of the circulating pump prevents the d.h.w. piping system from cooling down.
15.5.2 Setpoint for legionella function The setting range for the legionella setpoint is 60…95 °C (operating line 105). When using storage tanks with 2 sensors, the d.h.w. temperature must reach the setpoint at both sensors. 15.6 Priority of d.h.w. charging 15.6.1 General Depending on the heat output available, it may be practical to restrict the amount of heat delivered to the heating circuits during d.h.w. charging. In this case, d.h.w. heating is given priority over space heating.
15.6.3 Shifting priority General During d.h.w. heating, the amount of heat supplied to the heating circuits is throttled should charging lead to a shortage of heat. Generation of the valid flow temperature setpoint can be selected via operating line 106: 1 = flow temperature setpoint is determined by the request for d.h.w. 2 = flow temperature setpoint is determined by a maximum selection of the valid requests for d.h.w.
15.7 Pump overrun 15.7.1 General To prevent the accumulation of heat, it is possible to select overrun of the intermediate circuit pump and of the storage tank charging pump, depending on the type of plant. The type of priority has no impact on the overrun function. By contrast, pump overrun can be interrupted by d.h.w. discharging protection, or extended by forced signals. Simultaneous overrun of heating circuit pumps and d.h.w. pumps is permitted. 15.7.
15.10 D.h.w. heating with storage tanks 15.10.1 General The RVD260 supports the following types of plant: • Plants with coil type storage tanks where the heating circuit and d.h.w. heating use a common heat exchanger • Plants with stratification storage tanks where the heating circuit and d.h.w. heating use 2 separate heat exchangers Space heating and d.h.w. heating use a pump or mixing heating circuit. The heat for storage tank charging is delivered by an intermediate circuit pump.
15.10.2 D.h.w. charging The kind of d.h.w. charging is to be selected via operating line 99. • Charging by heating: When selecting 0 on operating line 99, the d.h.w. storage tank is charged exclusively via the heating system throughout the year • Charging in changeover mode: When selecting 1, 2 or 3 on operating line 99, the d.h.w.
15.10.5 Forced charging In the case of forced charging, the storage tank is also charged when the d.h.w. temperature does not drop below the switching differential. This takes place depending on the program selected via operating line 101: • Daily at the beginning of the first release period (release according to the d.h.w. program or according to the heating program), or • Daily at midnight if d.h.w. heating is always released (24-hour program). Forced charging is switched off when the d.h.w.
If a storage tank uses an electric immersion heater, the setpoint adjustment is no longer valid since in that case, the thermostat of the electric immersion heater ensures temperature control of the storage tank. 15.11 D.h.w. heating with stratification storage tank This chapter only covers the functions used in addition to d.h.w. heating with storage tanks. 15.11.1 General D.h.w. heating with stratification storage tanks is covered by plant types 1–8, 2–6 and 4–8.
Setting 2: A flow temperature drop of 20% is tolerated. The behavior is the same as that with d.h.w. heating directly via heat exchanger (setting on operating line 55 = 2). When d.h.w. charging is finished, the circulation circuit is first charged for 5 minutes before the request for d.h.w. heating becomes invalid. 15.12 Direct d.h.w. heating 15.12.1 General Direct d.h.w. heating via heat exchanger is covered by plant types x–4.
This takes place when… • during the waiting time, there was no demand for heat (neither from the heating circuit nor from d.h.w.), • the waiting time since the valve opened last has elapsed.
T Mode of operation T T T Plant without flow switch Operating line 56 55 0 ≠4 1, 2, 3 4 0, 1 4 2 4 3 Plant with flow switch Function, compensation of heat losses Flow switch Circulating pump Full compensation Full compensation No compensation Partial compensation, flow temperature drop up to 20% permitted Full compensation No No Yes Yes No Yes No Yes Yes Yes Explanations relating to the settings on operating line 55: • Settings 0 and 1: No d.h.w. heating when there is no consumption.
16 Function block: Valve actuator d.h.w. 16.1 Operating lines Function block "Valve actuator d.h.w." provides settings for the heating engineer. Line 111 112 113 114 115 116 117 118 119 120 124 Function, parameter Opening time actuator in the d.h.w. circuit Closing time actuator in the d.h.w. circuit P-band d.h.w. control Integral action time d.h.w. control Derivative action time d.h.w. control Setpoint boost d.h.w. charging Maximum setpoint d.h.w.
16.4 Setpoint boosts Setpoint boost ensures that the flow temperature required by the consumer to perform its function (control) is delivered by the heat source. 16.4.1 Charging boost Charging boost for the d.h.w. setpoint can be set on operating line 116. This is the difference of heat request to the heating medium (setpoint) and setpoint of the d.h.w. in the storage tank. 16.4.2 Flow temperature boost The boost for the mixing valve or the heat exchanger in the d.h.w.
16.7 Adjustable load limit 16.7.1 Adjustment to the season To enable the controller to provide stable d.h.w. temperature control also when connection conditions vary (summer/winter operation), it must adjust the running time. This adjustment is made via the current maximum stroke. When the plant is switched on, the assumption is made that the maximum stroke is 50%. If the controller opens the actuator by more than 50%, the stroke model constantly adjusts the current maximum stroke ”toward 100%".
16.7.3 Child-proofing If the d.h.w. tap is repeatedly opened (e.g. by children playing with the tap), the childproofing function prevents the load limit function from being effected more often than necessary, thus preventing excessive d.h.w. temperatures. If, within 10 seconds, the d.h.w. tap is opened more than twice, the controller provides d.h.w. heating without support of the load limit function. 76/134 Siemens Building Technologies Basic Documentation RVD260 16 Function block: Valve actuator d.h.w.
17 Function block: Assignment of d.h.w. 17.1 Operating line Function block "Assignment of d.h.w." provides a setting for the heating engineer. Line 125 Function, parameter Assignment d.h.w. charging 17.2 Factory setting (range) 0 (0…2) Unit Assignment d.h.w. charging Operating line 125 is used to select for which controllers in an LPB system the d.h.w. is provided or, in other words, which heating circuits get their d.h.w. from the same source.
18 Function block: Extra legionella functions In d.h.w. systems with storage tank, the legionella function prevents the growth of legionella viruses. This is accomplished by raising the d.h.w. temperature at a certain interval. 18.
In the case of direct d.h.w. heating without circulating pump, the set value has no impact (no dwelling time). 18.1.5 Operation of circulating pump During the time the legionella function is performed, the circulating pump can be forced to operate. This function ensures that hot water also circulates through the plant’s hot water distribution system. The setting (0 or 1) is to be made on operating line 128.
The following graph shows the behavior of the legionella function depending on the d.h.w. temperature. TBWx ON OFF ON OFF ON OFF TBWx TBWw SDBW t Circulating pump Forced charging Release of legionella function Start conditions for legionella function fulfilled Start dwelling time Reset dwelling time Start dwelling time Dwelling time has elapsed D.h.w. temperature D.h.w. temperature setpoint Switching differential of d.h.w. charging Time It set, a maximum d.h.w. charging time is also active here.
19 Function block: Multifunctional relays 19.1 Operating lines Function block "Multifunctional relays" provides settings for the heating engineer. Line 129 130 Function, parameter Function multifunctional relay K6 Function multifunctional relay K7 19.2 Factory setting (range) 0 (0…5) 0 (0…5) Unit Mode of operation and settings Function block "Multifunctional relays" enables further optional functions to be parameterized on operating lines 129 and 130, depending on the type of plant.
20 Function block: LPB parameters 20.1 Operating lines Function block "LPB parameters" provides settings for the heating engineer. Line 131 132 133 134 135 136 137 Function, parameter Device number for bus address Segment number for bus address Clock mode Bus power supply, operating mode and status indication Outside temperature source Locking signal gain Response to uncritical locking signals from data bus 20.2 Factory setting (range) 0 (0…16) 0 (0…14) 0 (0…3) A (A/0/1) A (A/00.01…14.
• Time of day on the controller can be Adjustment readjusted and, at the same time, readjusts the system time since the change Controller time System time is adopted by the master • The controller's time of day is nevertheless automatically and continually matched to the system time • Time of day on the controller can be 3 Adjustment readjusted, which also changes the system time Controller time System time • The controller’s time of day is used for the system Only one controller per system may be used as t
20.3 Locking signals 20.3.1 Basics The following functions use locking signals and send them to the heat exchangers and consumers: • Minimum limitation of boiler return temperature • Protective boiler startup • D.h.w. priority With the heat exchanger and consumer controllers, it can be set on operating line 136 (locking signal gain) to what degree they shall respond to a locking signal. The locking signal gain can be adjusted between 0 and 200%.
20.5 Uncritical locking signals 20.5.1 General Uncritical locking signals are generated in connection with d.h.w. priority (absolute and shifting) and only act on the heating circuits and heat exchangers. There are… • "Controller-internal locking signals", and • "Locking signals from the data bus (LPB)". For more detailed information, refer to chapter 15.6 "Priority of d.h.w.
21 Function block: Device functions 21.1 Operating lines Function block "Device functions" provides settings for the heating engineer. Line 141 142 143 144 145 146 Function, parameter Pulse lock actuator Frost protection for the plant Flow alarm Changeover winter-/summertime Changeover summer-/wintertime Pump kick 21.2 Factory setting (range) 1 (0/1) 1 (0/1) --:-- (--:--/0:10…10:00) 25.03 (01.01…31.12) 25.10 (01.01…31.12) 1 (0/1) Unit h dd.mm dd.
21.3.3 Mode of operation without outside sensor Frost protection for the plant operates in 2 stages: 1. If the flow temperature (sensor B1) falls below 10 °C, the heating circuit pump is activated for 10 minutes at 6-hour intervals. 2. If the flow temperature falls below 5 °C, the heating circuit pump is activated and runs continuously. When active, the respective frost protection stage is switched off when the flow temperature exceeds the limit value by the switching differential of 1 K. 21.3.
TV w y x tA tA ERROR t1 t2 2524D05 tA t Flow alarm t t1 t2 tA TV w x y Time Start of ERROR display End of ERROR display Waiting time (set on operating line 143) Flow temperature Setpoint Actual value Setpoint band • At t1, an error message is delivered; during the time tA (set on operating line 143), the actual value stayed below setpoint band y • At t2, the error message is reset; actual value x reached setpoint band y The flow alarm can be deactivated by entering --:--.
Monitoring undertemperature With plant types x–4, this function is required to track bottlenecks in the heat supply from the district heating network. Monitoring of undertemperature triggers an error message when, during a request for heat, the flow temperature falls by more than 10 K below its setpoint for a defined period of time. This period of time can be set on operating line 143. The flow alarm becomes inactive as soon as the limit is exceeded again.
22 Function block: M-bus parameters 22.1 Operating lines Function block "M-bus parameters" provides settings for the heating engineer. Line Function 151 M-bus primary address 152 M-bus secondary address 153 Baud rate 154 Forwarding of M-bus power control signals (load management) M-bus power control in the heating circuit (load management) 155 22.
22.5.2 Load management of heating system Load management of the heating system uses internal locking signals or acts on the request for heat (refer to relevant sections) to decrease or increase heat consumption. The validity of the request for heat is not influenced. The compensating variable is not influenced either since load management is a short-term intervention. 22.5.
23 Function block: PPS parameters This function block defines the devices and actions at the PPS. The RVD260 is the master; the connected devices (max. 2) are slaves. 23.1 Line 158 Operating lines Function, parameter Impact of room unit functions on the heating circuits when using 1 room unit 23.
24 Function block: Test and display 24.1 Operating lines Function block "Test and display" provides settings and displays for the heating engineer. Line 161 162 163 164 165 169 170 Function, parameter Sensor test Display of setpoint Relay test Speed of controlled pump Test of digital input Display of active limitations Software version 24.
Using the line selection buttons and , it is possible to switch from the sensor test to the setpoint test, and vice versa; in that case, the selected code is maintained. 24.4 Relay test The relay test is made to manually energize each relay contained in the RVD260 in and . order to check its state.
24.7 Limitations Active limitations are displayed on operating line 169. The query is made by pressing buttons and . Every limitation is assigned a code and the respective limitation symbol.
25 Function block: Solar d.h.w. 25.1 Operating lines Function block "Solar d.h.w." provides settings for the heating engineer.
25.3 Functions 25.3.1 Temperature differential ON/OFF solar Operating lines 201 and 202 are used to set the temperature differential for switching solar d.h.w. charging on and off. A sufficiently large temperature differential of collector and d.h.w. storage tank is required for charging; in addition, the collector must have reached the minimum charging temperature.
25.3.3 Minimum running time When the collector pump is activated, it keeps running for a minimum time of tMin = 20 seconds. This minimum on time is active with all functions that switch on the collector pump.
25.3.5 Overtemperature protection for collector Operating line 204 is used to set the temperature that protects the collector against overheating. If there is a risk of collector overtemperature, storage tank charging is continued beyond maximum limitation of the charging temperature (set on operating line 206) until maximum limitation of the storage tank temperature is reached (set on operating line 207), aimed at lowering the amount of surplus heat.
2541D10 2K 1K 1K TRk ON OFF SDON TRk TSp TKol Temperature differential ON Recooling setpoint Storage tank temperature Collector temperature ON/OFF T t Collector pump Temperature Time • If the storage tank temperature lies at least 2 K above the recooling setpoint and by at least temperature differential ON above the collector temperature, the collector pump is activated: TSp > TRk + 2 K and TSp > TKol + SDON • If the collector temperature rises to a level of 2 K below the storage tank temperature,
Evaporation protection of the heat conducting medium (pump off) takes priority over overtemperature protection which would activate the pump. 25.3.8 Maximum limitation of charging temperature Operating line 206 is used to set the maximum limitation for the charging temperature. When the maximum charging temperature in the storage tank is reached, the collector pump is deactivated.
25.3.10 Collector start function The controller is supplied with the collector start function deactivated. Since the collector’s temperature (primarily vacuum pipes) cannot be reliably acquiredwhen the pump is off, the pump can be activated based on an adjustable gradient [min/K]. Operating line 208 is used to set the gradient for the collector start function. The gradient represents the collector’s off temperature increase per minute.
26 Function block: Refill functions 26.1 Operating lines Function block "Refill functions" provides settings for the heating engineer.
26.3 Mode of operation Primary pressure 2510D03 26.3.1 Overview of functions Secondary pressure Switching differential Relative secondary minimum pressure Refill valve Reset Alarm: Maximum refill period per charge Minimum secondary underpressure period Refill locking time after shut down Maximum period per refill Time 26.3.
26.3.6 Function of primary pressure sensor (U2) The function of terminal B7/U2 is to be selected via operating line 53 (refer to chapter 11 "Function block: Plant configuration"). For the refill function, the secondary pressure sensor (U1) is required. The primary pressure sensor (U2) can be used for… • display, or • monitoring. When monitoring the primary pressure, recharging is locked if the pressure on the primary side drops below the relative secondary minimum pressure plus the switching differential.
27 Function block: DRT and maximum limitation of return temperature 27.1 Operating lines Function block "DRT and maximum limitation of return temperature" provides settings for the heating engineer.
27.2.
If set to inactive (operating line 235 = ---), there is no maximum limitation of the return temperature during the time the legionella function is activated. If both the heating circuit and the d.h.w. circuit call for heat and maximum limitation of the return temperature acts on both circuits, the higher limit value applies. If, with plant type 1–3, maximum limitation of the return temperature is deactivated (entry ---), the d.h.w.
27.4 Maximum limitation of return temperature differential (DRT function) 27.4.1 Mode of operation With the types of plant that have sensor B71 fitted in the secondary return of the heating circuit or in the secondary return of the heat exchanger, maximum limitation of the temperature differential (DRT, difference of primary and secondary return temperature) can be provided. With plant type 1–0, it is also possible to monitor the return temperature differential of heating circuit 2 using sensor B3.
28 Function block: Miscellaneous 28.1 Operating lines Function block "Miscellaneous" provides settings for the heating engineer. Line 236 237 238 240 241 242 243 244 Note: Function, parameter Limit function at contact H5 Limit value of volumetric flow or power limitation Integral action time of limit function at contact H5 Locking time after minimum limitation for the suppression of hydraulic creep Start of compensation (point of inflection), increase of reduced room temp.
28.3 Suppression of hydraulic creep 28.3.1 Mode of operation To avoid measuring errors in connection with heat metering due to extremely small flow rates, the flow through the 2-port valve in the primary return can be limited to a minimum (Ymin function). This ensures that consumers will not be able to draw heat that cannot be measured and billed. When the valve’s position reaches the minimum limit value, the valve is driven to the fully position.
28.4 Increase of reduced room temperature setpoint The reduced room temperature setpoint can be raised as a function of falling outside temperature. This prevents… • too great changes from the reduced to the nominal setpoint when outside temperatures are low, • extreme heating loads during the heating up phase. The starting point to be set is the outside temperature in °C (start of compensation, operating line 241).
29 Function block: Operation locking functions 29.1 Operating lines Function block "Operation locking functions" provides settings for the heating engineer. Line 250 251 Function, parameter Locking on the software side Locking of "Locking functions" level on the hardware side (operating lines 226...250) 29.2 Factory setting (range) 0 (0…4) (0/1) Unit Locking settings on the software side The settings on all levels, or a certain part of them, can be locked on the software side.
30 Combination with PPS devices 30.1 General • PPS devices are digital peripheral devices for connection to the PPS (point-to-point interface, terminals A6–MD) of the controller. Such devices are presently the following: − Room units QAA50.110/101 and QAW70 • The room temperature acquired by a room unit is adopted by the controller. If the room temperature shall not be considered by the control functions, room influence on operating line 70 must be set to 0.
30.2.2 Overriding the operating mode From the QAA50.110/101 the operating mode of the RVD260 can be overridden. This is made with the operating mode selector and the economy button. For the room unit to act on the RVD260, the controller work in automatic operation. The impact of the room unit’s operating mode selector on the RVD260 is as follows: Op. mode QAA50.110/101 Operating mode RVD260 Automatic operation; temporary overriding with the economy button of the QAA50.
For that purpose, the QAW70 has the following operating elements: • Operating mode button • Economy button (also called presence button) • Knob for readjustment of the nominal room temperature setpoint • Buttons for selecting the operating lines • Buttons for readjusting values 30.3.2 Overriding the operating mode The controller’s operating mode can be overridden from the QAW70. This is made with the operating mode button and the economy button.
13 14 15 16 D.h.w. temperature -- Flow temperature Holidays (number of switch-off weekdays) 17 Reset to default values Display with plant type x–0: --No function Display of heating circuit flow temperature Heating circuit switches to protection mode . D.h.w.
30.3.7 Freely programmable input For a number of remote control and extra functions, the QAW70 room unit has a freely programmable input. This input offers the following connection choices: • Analog room sensor QAW44 (NTC sensing element) • Telephone contact • Contact for common fault or window contact The input is to be configured via operating lines 55 and 56 of the QAW70 room unit.
31 Handling 31.1 Operation 31.1.1 General Display and operating elements Front of RVD260 1 2 3 4 5 6 7 8 9 Operating mode buttons Display (LCD) Buttons for selecting the operating lines Button for manual control ON/OFF Button for d.h.w.
31.1.2 Analog operating elements Selection of operating mode Selection of operating mode: • 3 buttons for selecting the heating circuit’s operating mode • 1 button for d.h.w. heating The required operating mode is activated by pressing the respective button. Each button has an integrated LED; the currently active operating mode is indicated by the respective LED when lit.
31.1.4 Controller in "unoperated state" The controller works in "unoperated state" when no button has been pressed for the last 8 minutes, or when one of the operating mode buttons was previously pressed. When in ”unoperated state”, the time of day and all actual values can be queried by and . The code numbers of the actual values are identical with those pressing on operating line 161. Any active limitations are displayed with or according to their priorities. They can be queried on operating line 169.
31.2 Commissioning 31.2.1 Installation instructions The RVD260 is supplied complete with Installation Instructions. They provide detailed information about installation, wiring, commissioning, function checks and settings. The instructions address trained specialists. Each operating line has an empty field where the set value can be entered. The Installation Instructions together with the plant’s documentation should be kept in a safe place! 31.2.
31.3 Manual control Manual control enables the heating system to be controlled manually during the commissioning phase or in the event of fault. . The LED for manual control is lit and the LED for the It is activated by pressing operating mode extinguishes. The control outputs are switched as follows: • The power supply to the valves on the primary side (heating circuits or common flow) will be removed.
Low-voltage Mains voltage 32 Engineering 32.1 Connection terminals DB MB A6 MD B9 B1 M B3 B7/U2 B71/U1 LPB Ground for LPB Room unit/room sensor PPS Ground for PPS Outside sensor Flow sensor heating circuit/common flow Ground for sensors Flow sensor d.h.w.
32.
32.6 Connection diagrams 32.6.1 Low-voltage side 32.6.2 Mains voltage side A6 B1 B12 B3 B31 B32 B7 B71 B72 B9 H5 Kx N1 P1 M1 M2 M3 M4 U1 U2 Y1 Y5 Y7 * ** Room unit Flow sensor heating circuit 1/common flow* Flow sensor heating circuit 1/heating circuit 2* Flow sensor d.h.w./heating circuit 2* D.h.w. storage tank sensor D.h.w.
33 Mechanical design 33.1 Basic design The RVD260 consists of controller insert and base. The controller insert contains the electronics, the power section and 10 relays. The base accommodates the connection terminals. The front of the controller carries the operating elements and the backlit LCD. The Operating Instructions are inserted at the rear of the front cover. When the cover is closed, only the LCD can be seen. The RVD260 has the standard overall dimensions 96 mm x 144 mm.
33.
34 Addendum 34.1 Technical data For technical data, refer to Data Sheet N2515. 34.2 Revision history Edition 1.0 is the first publication of this document. For this reason, there is no need to list any alterations.
34.3 Index A Absolute priority.........................................................63 Access rights ...........................................................121 Acquisition of measured values.................................24 Adaptation to the season...........................................75 Addressing the devices .............................................82 Addressing, M-bus ....................................................90 Assignment d.h.w. charging ....................................
F Feeding the circulating water .................................... 69 Flow alarm ................................................................ 87 Flow sensor............................................................... 24 Flow switch ............................................................... 71 Flow temperature boost ............................................ 74 Flush-panel mounting ............................................. 127 Forced charging ..............................................
Manual storage tank charging ...................................67 Master clock ..............................................................82 Max. limitation in heating mode ...............................107 Max. limitation of charging temperature solar .........101 Max. limitation of flow temperature heating circuit ....59 Max. limitation of primary return temp. in d.h.w. mode .......................................................................107 Max. limitation of primary return temperature ......
Resetting the counters, refill function ...................... 105 Resolution, M-bus signals ......................................... 91 Return sensor ..................................................... 26, 27 Return temperature differential ............................... 109 Room model ........................................................ 25, 30 Room model temperature ......................................... 52 Room sensor QAW44 ............................................. 118 Room sensors .......
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