D 262 - Data Brochure Boiler Control 262 12/08 The Boiler Control 262 is a micro processor based control designed to maximize the comfort and efficiency of a hydronic heating system. The control is designed to operate in two distinct modes. MODE —1—(Two Stage Boiler & DHW) allows for the control of two separate on /off boiler stages (or one low / high fire) based on outdoor air temperature, control for indirect Domestic Hot Water (DHW) generation and a Setpoint load.
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) Troubleshooting. The Sequence of Operation section has four 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 refer to the sub sections that apply to your installation.
User Interface Display Item Field Number Field Displays an abbreviated name of the selected item Menu Field Displays the current menu Displays the current value of the selected item View Adjust Monitor °F °C min hr sec UnOcc Ovr Schd Misc 1 DHW Displays the current status of the control’s inputs, outputs and operation Menu Minimum Maximum ! 12 Status Field Boiler Demand DHW Demand Setpoint Demand WWSD { Item Buttons Selects Menus, Items and adjusts settings Symbol Description 12 1 D
Sequence of Operation Section A Section B Page 4 - 6 Page 6 - 10 General Operation Boiler Reset Section C Section D Domestic Hot Water (DHW) Page 10 - 12 Setpoint Page 12 Section A —General Operation POWERING UP THE CONTROL When the Boiler Control 262 is powered up, the control displays the control type number in the LCD for 2 seconds. Next, the software version is displayed for 2 seconds.
Light (LITE) The LITE setting is selected if the boiler(s) that is used has a low thermal mass. This means that the boiler(s) has a very small water content and has very little metal in the heat exchanger. A boiler that has a low thermal mass comes up to temperature quite rapidly when fired. This is typical of many copper fin-tube boilers. The minimum inter-stage delay for the LITE setting is two minutes. The Medium setting is selected if the boiler(s) that is used has a medium thermal mass.
External Unoccupied An external signal can place the 262 into an UnOccupied mode. Any time the UnO Sw (18) and the Com Sen (19) terminals are shorted together, the control operates in the UnOccupied mode. When in the UnOccupied mode, the UnOcc segment is displayed in the LCD. The 262 adjusts the supply water temperature based on the UnOcc setting made in the control.
BOILER START (Boil STRT) (RESETRATIO) Boil MAX 210 (99) Boil DSGN 190 (88) OUTDOOR START (OUT STRT) (RESET RATIO) The OUT STRT temperature is the outdoor air temperature at which the control provides the Boil STRT supply water temperature to the system. 170 (77) Boil MIN 150 (66) Boil SETB OUTDOOR DESIGN (OUT DSGN) (RESET RATIO & CHARACTERIZED HEATING CURVE) 130 (54) The OUT DSGN is the outdoor air temperature that is the typical coldest temperature of the year where the building is located.
ROOM OCC & UNOCC (ROOM) (CHARACTERIZED HEATING CURVE) The ROOM is the desired room temperature for the boiler zone(s) and it provides a parallel shift of the Characterized Heating Curve. The room temperature desired by the occupants is often different from the designed indoor temperature (Boil INDR). If the room temperature is not correct, adjusting the ROOM setting increases or decreases the amount of heat available to the building.
Boosting (BOOST) Typical settings for the Boost function vary between 30 minutes and two hours for a building that has a fast responding heating system. For a building that has a slow responding heating system, a setting between four hours and eight hours is typical. After a Boost time is selected, the setback timer must be adjusted to come out of setback some time in advance of the desired Occupied time. This time in advance is normally the same as the Boost setting.
2) as described in Section B1. With the RTU connected, the 262 measures the actual ROOM temperature. Indoor temperature feedback fine tunes the supply water temperature in the system to prevent over heating or under heating. The RTU allows the user to adjust the desired room temperature at the RTU. Remote sensor capability is also available through an RTU. See the Data brochure for the RTU you are connecting.
Internal Demand (DHW SENS = DHW) If the control receives a DHW demand from a DHW sensor attached to the Com Sen and the DHW 10K terminals (19 and 20), the Boil TRG temperature is at least as hot as the DHW TANK setting plus 40˚F (22˚C). DHW DURING UNOCCUPIED External Demand (Aquastat ) If an external DHW Demand is used, the control can either continue operation of the DHW system as it would during the Occupied period or the control can ignore a call for DHW as long as the control is in an UnOccupied mode.
Section C3 —DHW with Low Temperature Boilers (Mode = —1—) 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 D —Setpoint (Mode = —1—) Section D1 Setpoint Section D1—General Setpoint Operation (Mode = —1—) The 262 can handle setpoint loads which are high temperature loads connected to the boiler loop that are not heating or DHW loads. 3 4 5 ComDHW Setp Dem Dem Dem SETPOINT DEMAND The 262 registers a Setpoint Demand when a voltage between 24 or 240 V (ac) is applied across the Com Dem and the Setp Dem terminals (3 and 5). Once voltage is applied, the Setpoint Demand pointer turns on in the LCD.
Installation CAUTION Improper installation and operation of this control could result in damage to the equipment and possibly even personal injury. It is your responsibility to ensure that this control is safely installed according to all applicable codes and standards. This electronic control is not intended for use as a primary limit control. Other controls that are intended and certified as safety limits must be placed into the control circuit.
Boiler Demand 1 2 Boiler Demand To generate a Boiler Demand, a voltage between 24 V (ac) and 240 V (ac) must be applied across the Boiler Demand terminals (1 and 2). 24 to 240 V (ac) DHW Demand To generate a DHW Demand, a voltage between 24 V (ac) and 240 V (ac) must be applied across the Com Dem and the DHW Dem terminals (3 and 4).
DHW Sensor 19 20 Com DHW Connect the two wires from the DHW Sensor 071 to the Com and DHW terminals (19 and 20). The DHW Sensor is used by the 262 to measure the DHW tank temperature. 10K Sensor Either an Indoor Sensor, Slab Sensor, or Zone Control may be connected to the 10K input. If a sensor is used, connect the two wires from the sensor to the Com and 10K terminals (16 and 17).
6 7 Power L N V Test the Power Supply Make sure exposed wires and bare terminals are not in contact with other wires or grounded surfaces. Turn on the power and measure the voltage between the N and L terminals (6 and 7) using an AC voltmeter, the reading should be between 108 and 132 V (ac). Test the Powered Inputs Boiler Demand If a Boiler Demand is used, measure the voltage between the Boiler Demand terminals (1 and 2).
Connecting the Control Make sure all power to the devices and terminal blocks is off and remove any remaining jumpers from the terminals. 6 7 8 9 10 Power Boil DHW N L P1 Pmp/Vlv Reconnect the terminal blocks to the control by carefully aligning them with their respective headers on the control and then pushing the terminal blocks into the headers. The terminal blocks should snap firmly into place.
Access Levels The tekmar Boiler Control 262 comes with four Access Level settings. These Access Levels restrict the number of Menus, Items, and Adjustments that can be accessed by the user. The four access levels are Limited (LTD), User (USER), Installer (INST) and Advanced (ADV). The access level of the control is found in the Miscellaneous (Misc) menu when the Lock/Unlock DIP switch is set to the Unlocked position. In the Advanced access level, all of the control settings are available to the user.
262 View Menu (1 of 1) Access Level Description Range Se c ti LT on D US ER IN ST AD V Item Field •••• B2 B2 B2 ••• •••• • Current outdoor air temperature as measured by the outdoor sensor. This is the default display for the control. MODE = —1— Target room air temperature. “– – –” denotes no heat is required. 10K = INDR MODE = —1— Measured room air temperature at the indoor sensor. 10K = INDR MODE = —1— This is the signal that is being received from a tekmar Zone Control.
262 Adjust Menu (1 of 4) Access Level Description Range Se c ti LT on D US E IN R ST AD V Item Field A B1 Occ B1 UnOcc B2 •• Sets the operating Mode for the control. —1— or —2— MODE —1— = (Heating, DHW, and Setpoint) MODE —2— = (Dedicated DHW) Default = MODE —1— •••• The desired room air temperature during an Occupied period. Note: There is only a 13°F adjustment in the LTD access level.
262 Adjust Menu (2 of 4) B1 B1 B1 B1 B1 B1 A A A A A A C1 C1 Copyright © D 262 -12/08 Range E IN R ST AD V Description US Se ct i LT on D Item Field Access Level The starting water temperature used in the reset ratio calculation for the heating system. 35 to 150˚F (2 to 66˚C) DIP switch = Reset Ratio MODE = —1— Default = 70°F (21°C) The outdoor starting temperature used in the reset ratio calculation for the heating system.
262 Adjust Menu (3 of 4) Se ct i LT on D US E IN R ST AD V Item Field Access Level C1 Occ C1 UnOcc C4 C1 Occ C1 UnOcc C2 D1 Occ D1 UnOcc D1 B1 Occ ••• ••• • •• •• •• •• •• •• ••• Description Range The DHW storage tank’s temperature during the Occupied period. OFF, 70 to 190˚F (OFF, 21 to 88˚C) DHW SENS = DHW DHW THRU ≠ NONE Default = 140°F (60°C) The DHW storage tank’s temperature during the UnOccupied period.
262 Adjust Menu (4 of 4) ••• B1 UnOcc Description Range U Se ct i LT on D Item Field SE IN R ST AD V Access Level The system’s warm weather shut down during the UnOccupied period. DIP switch = Setback MODE = —1— 35 to 100 ˚F, OFF (2 to 38 ˚C, OFF) Default = 60 °F (16°C) OFF, 0:10 to 40:00 min • The maximum length of time that the boiler pump will continue to operate after the heating and DHW demands have been removed.
262 Misc (Miscellaneous) Menu (1 of 1) Access Level Range E IN R ST AD V Description US LT D Item Field ••• The units of measure that all of the temperatures are to be displayed in by the control. The operating mode for the back lighting on the LCD as well as the time of keypad inactivity until the control automatically returns to the default display.
2 RTU Adjust Menu (1 of 1) Access Level Item Field Description Range Actual Setting Se c ti LT on D US E IN R ST AD V R TU R TU 2 3 06 06 •••••• B1 Occ The desired room air temperature during an UnOccupied period for the heating zone. Note: There is only a ±3°F adjustment in the LTD access level. ••••• B1 UnOcc The desired room air temperature during an Occupied period for the heating zone. Note: There is only a ±3°F adjustment in the LTD access level.
262 RTU Schd (Schedule) Menu (1 of 1) Access Level Item Field Description Range The type of setback override that is in effect.
Step 3 - The Stage 2 contact is turned on for 10 seconds. After 10 seconds, the Stage 1, Stage 2 and Boil P1 contacts are shut off. NOTE: Only if there is a boiler demand can the control be paused in step 3. Step 4 - MODE —1— If a DHW Pump is selected as the DHW device, the DHW Pmp / Vlv contact is turned on for 10 seconds and is then shut off. If a DHW Valve is selected as the DHW device, the DHW Pmp / Vlv and Boil P1 contacts are turned on for 10 seconds and are then shut off.
Sketch the Piping in the System Sketch the piping of the system. This is a relatively simple step that tends to be overlooked, however it can often save hours of time in troubleshooting a system. Note flow directions in the system paying close attention to the location of pumps, check valves, pressure bypass valves and mixing valves. Ensure correct flow direction on all pumps. This is also a very useful step if additional assistance is required.
262 Monitor Menu (2 of 3) Note: To clear the recorded information in the specific Item field, press and hold Range • The total number of firing cycles that Stage 1 has had since this item was last cleared. This item can be used in conjunction with the B1 FIRE item to determine the average cycle length of Stage 1. If the cycle length is too short, a longer differential may allow a longer cycle length. •• The total number of running hours for Stage 2 since this item was last cleared.
262 Monitor Menu (3 of 3) Note: To clear the recorded information in the specific Item field, press and hold . Description Range US ER IN ST AD V t LT ion D Se c Item Field Access Level and • This item is an adjustable warning. If the air temperature measured by the indoor air sensor exceeds this setting, the control will display a warning message. 10K = INDR MODE = —1— 50 to 150˚F (10 to 66˚C) Default = 110°F (43°C) This item is an adjustable warning.
262 Error Messages (2 of 4) Error Displayed Description of Error The control was unable to read a piece of information stored in the Schedule menu. Because of this, the control was required to load the factory settings into all of the items in the Schedule menu. The control will continue to display the error message until all of the items available in the Schedule menu of the control have been checked by the user or installer. Note: Access level must be ADV in order to clear the error.
262 Error Messages (3 of 4) Error Displayed Description of Error The control is no longer able to read the Outdoor sensor due to an open circuit. In this case the control assumes an outdoor temperature of 32˚F (0˚C) and continues operation. Locate and repair the problem as described in the Data Brochure D 070. To clear the error message from the control after the sensor has been repaired, press either the Menu or Item button.
262 Error Messages (4 of 4) Error Displayed Description of Error The Remote Sensor 2 attached to the RTU is being read as a short circuit. The RTU will continue operation using all remaining sensors. If all of the sensors are unavailable, the control will continue to operate as if the RTU was not connected to the control. This error message can be cleared once the sensor has been repaired. Locate and repair the problem as described in the Data Brochure D 070.
Notes 35 of 36 Copyright © D 262 -12/08
Technical Data Boiler Control 262 Two Stage Boiler & DHW / Two Stage DHW Power supply Relays Demands Sensors included Optional devices — — — — — — — — — — — D 262, A 262’s, D 001, D 070, E 003, U 262. Microprocessor PID control; This is not a safety (limit) control. 4 lb.
