- Data Brochure D 264 Boiler Control 264 12/08 The tekmar Boiler Control 264 can control the supply water temperature from up to 4 on / off stages based on outdoor temperature, control for Domestic Hot Water (DHW) generation, or a setpoint requirement. A large easy to read display provides current system temperatures and operating status. The control has outputs for a primary pump and either a combustion air damper or alarm.
How To Use The Data Brochure This brochure is organized into four main sections. They are: 1) Sequence of Operation, 2) Installation, 3) Control Settings, and 4) Testing and Troubleshooting. The Sequence of Operation section has six sub-sections. We recommend reading Section A: General of the Sequence of Operation, as this contains important information on the overall operation of the control. Then read the sub sections that apply to your installation.
Display Menu Field Displays the current menu Number Field Displays the current value of the selected item Boiler Demand DHW / Setpoint Demand WWSD Item Field Displays an abbreviated name of the selected item Priority Override External Input Signal Offset Status Field Displays the current status of the control's inputs, outputs and operation Buttons Selects Menus, Items and adjust settings Symbol Description Stage Displays which stage relays are turned on.
Definitions The following defined terms and symbols are used throughout this manual to bring attention to the presence of hazards of various risk levels, or to important information concerning the life of the product. - Warning Symbol: Indicates presence of hazards which can cause severe personal injury, death or substantial property damage if ignored.
COMBUSTION AIR OR ALARM CONTACT The control has an isolated contact that can be used as either a combustion air damper contact or an alarm contact. This selection is made using the C. A. / Alarm DIP switch. Combustion Air (C. A.) When the DIP switch is set to C. A., terminals 12 and 13 can be used as a switch to operate a combustion air damper. This contact closes prior to the first stage operating on the control.
EXERCISING The control has a built-in exercising feature that is selected through the Exercise / Off DIP switch. To enable the exercising feature set the Exercise / Off DIP switch to Exercise. If exercising is enabled, the control ensures that each pump is operated at least once every 3 days. If a pump has not been operated at least once every 3 days, the control turns on the output for 10 seconds. This minimizes the possibility of the pump seizing during a long period of inactivity.
LO / HI OR LO / LO When using multi-stage boilers, a selection must be made regarding the staging order of the boiler(s). This adjustment is made in the ADJUST menu of the control. Lo / Hi If the Lo / Hi staging option is selected the control stages in sequence all of the stages in a single boiler. Once all of the stages are turned on, the control then stages in sequence all of the stages in the next boiler in the rotation sequence.
Hi (3) The Hi setting is selected if the boiler(s) that is used has a high thermal mass. This means that the boiler(s) has both a large water content and a large metal content. A boiler that has a high thermal mass is relatively slow in coming up to temperature. This is typical of many commercial cast iron and steel tube boilers. The Hi MASS setting stages on additional boilers at the slowest rate. DIFFERENTIAL An on / off heat source must be operated with a differential in order to prevent short cycling.
BOILER PUMP OPERATION In certain modes of operation, the control can operate the individual boiler pumps on each boiler in addition to the primary pump. The boiler pump turns on prior to the boiler firing and continues to run after the boiler is turned off. The amount of time that the boiler pump turns on prior to the boiler firing is determined by the BOIL MASS setting. If a BOIL MASS of Lo is selected, the boiler pump turns on 15 seconds prior to the boiler.
OUTDOOR DESIGN TEMPERATURE The outdoor design temperature is the outdoor air temperature that is the typical coldest temperature of the year where the building is located. This temperature is used when doing the heat loss calculations for the building. If a cold outdoor design temperature is selected, the boiler supply temperature rises gradually as the outdoor temperature drops. If a warm outdoor design temperature is selected, the boiler supply temperature rises rapidly as the outdoor temperature drops.
Fancoil (3) A fancoil terminal unit or air handling unit (AHU) consists of a hydronic heating coil and either a fan or blower. Air is forced across the coil at a constant velocity by the fan or blower, and is then delivered into the building space. Fin-Tube Convector (4) A convector terminal unit is made up of a heating element with fins on it. This type of terminal unit relies on the natural convection of air across the heating element to deliver heated air into the space.
Section E: Domestic Hot Water Operation Section E1 DHW Section E1: Domestic Hot Water (DHW) DHW DEMAND A DHW Demand is required in order for the control to provide heat to the DHW system. A DHW aquastat or setpoint control is used as a switch in the DHW demand circuit. Once the control detects a DHW demand, the DHW Demand pointer turns on in the LCD and the control operates the boiler to provide a sufficient boiler supply water temperature to the DHW tank. The control operates the pumps as described below.
DHW MODE 4 – DHW in Primary / Secondary with Priority When a DHW Demand is present, the DHW Pmp / Vlv contact (terminals 22 and 23) is closed and the primary pump contact is closed. Priority can only be obtained using external wiring. During a priority override, the DHW Pmp / Vlv contact is opened until the heating system has recovered before returning to DHW operation. This mode can be used if a DHW tank is piped in direct return and a DHW valve is installed.
Section E2: DHW with Low Temperature Boilers If DHW is to be incorporated into a low temperature system such as a radiant heating system, a mixing device is often installed to isolate the high DHW supply temperature from the lower system temperature. If a mixing device is not installed, high temperature water could be supplied to the low temperature system while trying to satisfy the DHW demand. This may result in damage to the low temperature heating system.
Section F: Setpoint Operation Section F1 Setpoint Section F1: Setpoint Setpoint operation is only available when DHW MODE is set to OFF. SETPOINT The control can operate to satisfy the requirements of a setpoint load in addition to a space heating load. A setpoint load overrides the current outdoor reset temperature and WWSD setting in order to provide heat to the setpoint load. SETPOINT DEMAND 7 8 A setpoint demand is required in order for the control to provide heat to the setpoint load.
Section G: External Input Operation Section G1 External Input Section G1: External Input EXTERNAL INPUT The control can accept an external DC signal in place of the outdoor sensor. The control converts the DC signal into the appropriate boiler target temperature between 50°F (10°C) and 210°F (99°C) based on the External Input Signal and Offset settings. To use the external input signal, the External Input / Stand Alone DIP switch must be set to External Input.
External Input Signal Conversion Tables CONVERSION TABLE 2 - 10 CONVERSION TABLE 0 - 10 0 - 20 mA* 0 - 10 V (dc) Boiler Target 4 - 20 mA* 2 - 10 V (dc) Boiler Target 0 0 – – – (OFF) 0 0 – – – (OFF) 2 1 50°F (10°C) 4 2 50°F (10°C) 4 2 68°F (20°C) 6 3 70°F (21°C) 6 3 86°F (30°C) 8 4 90°F (32°C) 8 4 103°F (39°C) 10 5 110°F (43°C) 10 5 121°F (49°C) 12 6 130°F (54°C) 12 6 139°F (59°C) 14 7 150°F (66°C) 14 7 157°F (69°C) 16 8 170°F (77°C) 16 8 174°F (79°C)
STEP THREE ———— ROUGH-IN WIRING All electrical wiring terminates in the control base wiring chamber. The base has standard 7/8” (22 mm) knockouts which accept common wiring hardware and conduit fittings. Before removing the knockouts, check the wiring diagram and select those sections of the chamber with common voltages. Do not allow the wiring to cross between sections as the wires will interfere with safety dividers which should be installed at a later time.
Output Connections 11 9 10 Prim Primary Pump Contact (Prim P1) Power L N The Prim P1 output terminal (11) is a powered output. When the relay in the control closes, 115 V (ac) is provided to the Prim P1 terminal (11) from the Power L terminal (10). To operate the primary pump, connect one side of the primary pump circuit to terminal 11 and the second side of the pump circuit to the neutral (N) side of the 115 V (ac) power supply. P1 115 V (ac) N L Combustion Air / Alarm Contact (C.A.
Boiler Return Sensor If a boiler return sensor is used, connect the two wires from the Boiler Return Sensor 071 to the Com and Boil Ret terminals (1 and 3). The boiler return sensor is used by the control to measure the boiler return water temperature. UnOccupied Switch If an external timer (tekmar Timer 032) or switch is used, connect the two wires from the external switch to the Com and UnO Sw terminals (1 and 5). When these two terminals are shorted together, the control registers an UnOccupied signal.
DHW Demand If a DHW demand is used, measure the voltage between the Setp / DHW and the Com Dem terminals (8 and 7). When the DHW demand device calls for heat, a voltage between 20 and 260 V (ac) should be measured at the terminals. When the DHW demand device is off, less than 5 V (ac) should be measured. V 7 8 20 to 260 V (ac) Com Setp/ Dem DHW Setpoint Demand If a setpoint demand is used, measure the voltage between the Setp / DHW and the Com Dem terminals (8 and 7).
9 10 Pr11im Test The Outputs Power L N Primary Pump (Prim P1) If a primary pump is connected to the Prim P1 terminal (11), make sure that power to the terminal block is off and install a jumper between the Power L and Prim P1 terminals (10 and 11). When power is applied to the Power N and Power L terminals (9 and 10), the primary pump should start.
Cleaning The Control The control’s exterior can be cleaned using a damp cloth. Moisten the cloth with water and wring out prior to wiping the control. Do not use solvents or cleaning solutions. Dip Switch Settings GENERAL DIP Switches The DIP switch settings on the control are very important and should be set to the appropriate settings prior to making any adjustments to the control through the User Interface.
Fixed Last / Off The Fixed Last / Off DIP switch selects whether or not the last boiler is to be included in the rotation sequence. If the DIP switch is set to Fixed Last, the last boiler is always the last to fire. This DIP switch is only active when the Rotate / Off DIP switch is set to Rotate. Fixed Lead / Off The Fixed Lead / Off DIP switch selects whether or not the first boiler is to be included in the rotation sequence.
Display Se c In tio st n Ad alle va r nc ed View Menu (1 of 1) Description Outdoor - Current outdoor air temperature as measured by the outdoor sensor. Boiler Supply - Current boiler supply water temperature as measured by the boiler supply sensor. This item is available in all modes. D1 E1 F1 Boiler Target - Boiler target temperature is the temperature the control is currently trying to maintain at the boiler supply sensor + / – ½ of the differential.
Display © 2008 Se c In tio st n Ad alle va r nc ed Adjust Menu (1 of 4) Description Range D1 Room Occupied - The desired room air temperature during the occupied period. 35 to 100°F (2 to 38°C) Default = 70°F (21°C) D1 Room Unoccupied - The desired room air temperature during the unoccupied period. 35 to 100°F (2 to 38°C) Default = 65°F (18°C) F1 External Input Signal - Selects the range of the external input signal.
Display Se c In tio st n Ad alle va r nc ed Adjust Menu (2 of 4) Description Range D1 Terminal Unit - The type of terminal units that are being used in the heating system. 1 (HRF1), 2 (HRF2), 3 (COIL), 4 (CONV), 5 (RAD), 6 (BASE) Default = 4 D1 Boiler Indoor - The design indoor air temperature used in the heat loss calculation for the heating system.
Display Se c In tio st n Ad alle va r nc ed Adjust Menu (3 of 4) B1 Description Staging - Selects the firing sequence of the stages when using multi-stage boilers. This item is only available in Mode 3. © 2008 Range lohi, lolo Default = lohi OFF 1 (parallel, no priority), 2 (parallel, priority), 3 (pri-sec, no priority), 4 (pri-sec, priority) Default = OFF E1 DHW Mode Selects the DHW mode of operation.
Display Se c In tio st n Ad alle va r nc ed Adjust Menu (4 of 4) Description Range D1 35 to 100°F, OFF WWSD UnOccupied The system’s warm weather shut (2 to 38°C, OFF) down temperature during the UnOccupied period. Default = 60°F (16°C) C1 Primary Pump Purge The maximum length of time that the primary pump will OFF, 0:10 to 19:55 min continue to operate after the boiler demand has been Default = 0:20 min removed.
Testing the Control The control has a built-in test routine that is used to test the main control functions. The control continually monitors the sensors and displays an error message whenever a fault is found. See the following pages for a list of the control’s error messages and possible causes. When the Test button is pressed, the test light is turned on. The individual outputs and relays are tested in the following test sequence. TEST SEQUENCE Each step in the test sequence lasts 10 seconds.
Error Messages The control was unable to read a piece of information stored in its memory. Because of this, the control was required to reload the factory settings into all of the items in the ADJUST menu. The control will stop operation until all of the items in the ADJUST menu of the control have been checked by the user or installer. Note: The Installer / Adv DIP Switch must be set to Adv in order to clear the error. The control is no longer able to read the outdoor sensor due to a short circuit.
Technical Data Boiler Control 264 Four Stage Boiler & DHW / Setpoint Optional devices D 264, A 264’s, D 001, D 070. Microprocessor PID control; This is not a safety (limit) control. 3.1 lb. (1400 g), Enclosure A, blue PVC plastic 6-5/8” H x 7-9/16” W x 2-13/16” D (170 x 193 x 72 mm) CSA C US, CSA 22.2 No 24 and UL 873, meets class B: ICES & FCC Part 15. Indoor use only, 30 to 120°F (0 to 50°C), < 95% RH non-condensing.
