Tekmar 274 Installation Manual Download Page 1

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274_D

11/12

- Data Brochure

Boiler Control 274

2012 274_D

11/12

The Boiler Control 274 operates up to four on/off boilers to provide outdoor reset operation, domestic hot water and setpoint

operation with priority. When operating as a tN4 System Control, the 274 can connect with up to 24 tN4 devices on a single
boiler bus. The 274 has primary pump sequencing capabilities along with a flow proof or combustion air damper proof
demand.

tN4 Compatible
24 Hour, 5-1-1, 7 Day Schedule
Flow or Combustion Air Proof
Four On/Off Boilers
Equal Run Time Rotation

•
•
•
•
•

Primary Pump Sequencing
DHW Operation
Optional DHW Sensor
Setpoint Operation

•
•
•
•

Additional functions include:

Input

Universal

Sensor

Included

Input

Universal

Sensor

Included

tN4

Boiler

Bus

Input

Outdoor Sensor

Included

0-10 or 2-10 V (dc)

from EMS

Output

Up to 4

On/Off Boilers

Input

115 V (ac)

Power Supply

Input

Flow OR
C.A. Proof

Output

Up to 2

Boiler Pumps

Output

DHW Pump

Primary Pump

Output

Combustion

Air Damper

OR Alert

Output

Primary

Pump

Input

DHW OR

Setpoint

Demand

Signal

Input

Boiler

Demand

Signal

Primary

DHW

VIEW

Demands

Setback

Boiler Control 274

One tN4, Four Stage Boiler & DHW / Setpoint

Menu

Item

Test

Boiler Demand
DHW / Setpoint Demand
Proof Demand

EMS Input Signal

Priority Override

Power

115 V ±10% 60 Hz 7 VA, 1150 VA max.

Relays

230 V (ac) 5 A 1/3 hp

Demands 20 to 260 V (ac) 2 VA

Made in Canada by

tekmar Control Systems Ltd

tektra 1020-02

Meets Class B:

Canadian ICES

FCC Part 15

For maximum heat,

press and hold

Test

button for 3 seconds.

not testing

testing

testing paused

oﬀ

red

Oﬀ

EMS

Rotate

Fixed Last

Pump Sequencer

Exercise

Oﬀ

Dat

e Code

H2050A

Signal wiring must be rated at least 300 V.

DHW

/Setp

Com

Dem

Pr.

Dem

–

BRet/

Com

tN4

Boil

Out

Com

Prim

Power

Do not apply power

DHW

/ P2

Fixed Lead

First On / Last Oﬀ

First On / First Oﬀ

Relay

C.A. /

Alert

Boiler

Demand

Sup

DHW

Zone Load Shedding

Up to 4 On/Oﬀ Boilers

Up to 2 On/Oﬀ Boilers & 2 Pumps

Up to 2 Lo/Hi Boilers

1 Lo/Hi Boiler & 1 Pump

1 Three Stage Boiler & Pump

1 Four Stage Boiler

Modes

Summary of Contents for 274

Page 1: ...Air Damper OR Alert OR OR Output Primary Pump Input DHW OR Setpoint Demand Signal Input Boiler Demand Signal Primary DHW 1 13 24 VIEW Demands Setback Boiler Control 274 One tN4 Four Stage Boiler DHW Setpoint Menu Item Test Boiler Demand DHW Setpoint Demand Proof Demand EMS Input Signal Priority Override Power 115 V 10 60 Hz 7 VA 1150 VA max Relays 230 V ac 5 A 1 3 hp Demands 20 to 260 V ac 2 VA Ma...

Page 2: ...r selecting and adjusting settings As you program your control record your settings in the ADJUST menu table which is found in the second half of this brochure Menu All of the items displayed by the control are organized into five menus View Adjust Time Schedule and Misc These menus are listed on the top left hand side of the display Menu Field To select a menu use the Menu button By pressing and ...

Page 3: ...on air damper relay is closed SCHEDULE MASTER Displays when the 274 is a schedule master WARM WEATHER SHUT DOWN Displays when the control is in warm weather shut down MINIMUM MAXIMUM Displays when the boil target or the boil supply is at a minimum or maximum Schd Wake UnOcc Sleep Away Schd Wake UnOcc Sleep Away Displays the current event of a schedule or scene POINTER Displays the control operatio...

Page 4: ...rature The characterized heating curve takes into account the type of terminal unit that the system is using Since different types of heating terminal units transfer heat to a space using different proportions of radiation convection and conduction the supply water temperature must be controlled differently The control uses the terminal unit setting to vary the supply water temperature to suit the...

Page 5: ...the room air temperature Radiator RAD A radiator terminal unit has a large heated surface that is exposed to the room A radiator provides heat to the room through radiant heat transfer and natural convection Baseboard BASE A baseboard terminal unit is similar to a radiator but has a low profile and is installed at the base of the wall The proportion of heat transferred by radiation from a baseboar...

Page 6: ...e the 274 s boiler maximum setting in order to prevent short cycling of the burner Mode The 274 control is capable of staging single stage two stage three stage and four stage on off heat sources As well in certain modes of operation the control is capable of controlling the individual boiler pumps The control has 6 modes of operation based on the type of staging and pump operation that is desired...

Page 7: ...l mass comes up to temperature quite rapidly when fired This is typical of many copper fin tube boilers The Lo mass setting provides a fast response to the heating system MED The MED setting is selected if the boiler that is used has a medium thermal mass This means that the boiler either has a large water content and a low metal content or a low water content and a high metal content This is typi...

Page 8: ...therefore it is the last boiler to be sequenced off Boiler Run Time in View Menu The running time of each boiler is logged in the view menu To reset the running time select the appropriate Boiler Run Time in the View menu and press and hold the Up and Down buttons simultaneously until CLR is displayed Boiler Differential Setting in Adjust Menu An On Off heat source must be operated with a differen...

Page 9: ...ensor within this delay period the Alert relay will close and the control will display the Boiler Alarm error message All boilers continue to operate if this error is present To clear the error press and hold the up and down buttons simultaneously for 5 seconds while viewing the error message in the View menu Combustion Air C A Damper When the Relay is set to Damper terminals 15 and 16 operate a c...

Page 10: ...ied and Wake periods When set to Off the control will ignore a DHW Demand for the duration of the UnOccupied and Sleep periods When using a DHW Sensor a second DHW temperature setting is available for the UnOccupied or Sleep period DIP Switch must be set to Setback to view UnOccupied items During the Away Scene DHW demands are ignored DHW Mode Setting in the Adjust Menu The control has six differe...

Page 11: ... supplied to the indirect tank There are two boiler target temperatures one for the heating system BOIL TARGET and one for the indirect DHW system BOIL DHW TARGET In this mode the DHW Demand can only be provided from an External Powered Demand or tN4 Setpoint Control in DHW mode All boilers are used for space heating requirements Boiler 2 is used for DHW when there is a DHW demand The dedicated DH...

Page 12: ...ame time the heating zones may have cooled off considerably after being off for a period of time When restarting the heating system after a DHW demand with priority the control shuts off the boiler and continues to operate the DHW pump while the primary pump is turned on This allows some of the DHW return water to mix with the cool return water from the zones and temper the boiler return water DHW...

Page 13: ...l maintain a supply temperature no higher than the Boil MAX setting Setpoint During UnOccupied When using a Powered Setpoint Demand the control has a Setpoint UnOccupied setting that allows the installer to select On or Off When set to On and the control receives a Setpoint Demand during an UnOccupied or Sleep period the control continues operation of the Setpoint system as it would during the Occ...

Page 14: ...nt priority The time allowed for Setpoint priority varies linearly between the above two points There is a manual setting also available in the adjust menu The priority timer does not start timing until priority is selected and both a Setpoint Demand and a Boiler Demand exist together Once the allowed time for priority has elapsed the control overrides the Setpoint priority and resumes space heati...

Page 15: ...or between the Out and Com terminals 3 and 2 2 10 V dc or 4 20 mA When the 2 10 V dc signal is selected an input voltage of 2 V dc corresponds to a boiler target temperature of 50 F 10 C An input voltage of 10 V dc corresponds to a boiler target temperature of 210 F 99 C As the voltage varies between 2 V dc and 10 V dc the boiler target temperature varies linearly between 50 F 10 C and 210 F 99 C ...

Page 16: ...signal is required at all times during pump operation A flow proof is generated by applying a voltage between 20 and 260 V ac across the Flow Proof terminals 30 and 31 Once voltage is applied the Proof Demand indicator is turned on in the LCD Once a pump contact is turned on a flow proof signal must be present before the flow proof delay has expired The flow proof demand is selected by setting the...

Page 17: ...er purge At the end of the purge the zone override is removed so the zone is allowed to close and turn off the primary pump If the last demand came from a non tN4 zone the purge period for the primary pump is adjustable between 10 seconds and 19 55 minutes Boiler Pump Operation The control can operate individual boiler pumps when set to Mode 2 4 or 5 Refer to the Boiler Operation section for more ...

Page 18: ...ettings 7 Day Repeats on a weekly basis and allows for separate event times for each day Schedule Type Day 24 Hour 5 11 7 day Saturday Sunday Monday Tuesday Wednesday Thursday Friday Schedule Mode The schedule mode can have either 4 or 2 events per day An event is a time at which the control changes the target temperature The event time can be set to the nearest 10 minutes If you wish to have the ...

Page 19: ...ighest thermostat address b 24 and ending at the lowest b 01 When the boiler supply temperature reaches the boiler minimum the first stage heating zones turn back on in order from b 01 to b 24 and then the second stage in order from b 01 to b 24 Cycle Length Setting in Adjust Menu tN4 The control includes an adjustment for the cycle length The cycle length adjustment allows for synchronization of ...

Page 20: ...ngs 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 Power must not be applied to any of the wires during the rough in wiring stage All wires are to be stripped to a length of 3 8 9 mm to ens...

Page 21: ...plied to the Com and Out terminals 2 and 3 A 0 20 mA signal can be converted to a 0 10 V dc signal by installing a 500 Ω resistor in parallel between the Com and Out terminals 2 and 3 A 4 20 mA signal can be converted to a 2 10 V dc signal by installing a 500 Ω resistor in parallel between the Com and Out terminals 2 and 3 Note DIP Switch must be set to EMS Dem Dem Setp Pr Com DHW 25 24 23 20 to 2...

Page 22: ...Prim P1 output on terminal 18 is a powered output When the relay in the control closes 115 V ac is provided to the Prim P1 terminal 18 from the Power L terminal 19 To operate the primary pump P1 connect one side of the primary pump circuit to terminal 18 and the second side of the pump circuit to the neutral Power N side of the 115 V ac power supply Primary Pump P2 The DHW P2 output on terminal 17...

Page 23: ...V ac OR 24 to 230 V ac Alert C A 16 15 Alert Combustion Air L or R N or C N or C tN4 Device Com tN4 Out Com 3 2 Step Five Testing the Wiring General The following tests are to be performed using standard testing practices and procedures and should only be carried out by properly trained and experienced persons A good quality electrical test meter capable of reading from at least 0 300 V ac 0 30 V ...

Page 24: ...trol and press the Test button 4 Use an electrical test meter and check for continuity between terminals 15 16 If the relay is set to Combustion Air Damper When the Combustion Air Damper symbol is displayed in the LCD there should be continuity When the Combustion Air Damper symbol is not displayed in the LCD there should be no continuity If the relay is set to Alert When the Alert symbol is displ...

Page 25: ...the control is accepting a boiler demand and using the outdoor sensor for outdoor reset Demands Setback Oﬀ EMS Rotate Fixed Last Pump Sequencer Exercise Oﬀ Fixed Lead First On Last Oﬀ First On First Oﬀ Lock Unlock Use this DIP switch to lock and unlock the Access Level of the 274 and all connected tN4 devices including tN4 thermostats For details see Access Level Once locked the access level in al...

Page 26: ...s only active when the Rotate Off DIP is set to Rotate If set to Fixed Last the last boiler is always the last to ﬁre Fixed Last will only work for boilers wired to the Relay 4 terminals 13 and 14 Demands Setback Oﬀ EMS Rotate Fixed Last Pump Sequencer Exercise Oﬀ Fixed Lead First On Last Oﬀ First On First Oﬀ Fixed Lead Off Use the Fixed Lead Off DIP switch to exclude the ﬁrst boiler in the rotati...

Page 27: ...This item is only available when DHW Mode is set to 5 or 6 VIEW 22 to 266 F 30 0 to 130 0 C USER INST ADV DHW SECTION E Current DHW tank temperature as measured by the DHW sensor Note This item is only available if Pump Sequencing DIP is set to Off AND either DHW Sensor is set to On or DHW Mode is set to 6 VIEW 22 to 266 F 30 0 to 130 0 C ADV BOILER RETURN Current boiler return water temperature a...

Page 28: ...NNING TIME SECTION C The total running time of Boiler 4 since this item was last cleared To clear this item press the Up and Down buttons simultaneously while viewing this item Note This item is only available when Boiler 4 is set to Auto VIEW hr Primary 1 0 to 9999 hours ADV PRIMARY PUMP 1 RUNNING TIME SECTION H The total running time of Pump 1 since this item was last cleared To clear this item ...

Page 29: ... DSGN is set between 60 to 45 F ADJUST 0 10 2 10 Default 0 10 ADV EMS SIGNAL SECTION G Selects the range of the Energy Management System input signal Note This item is only available when DIP set to EMS ADJUST 10 to 10 F 5 6 to 5 6 C Default 0 F C ADV OFFSET SECTION G Selects the range of the Energy Management System input signal Note This item is only available when DIP set to EMS ADJUST OFF 0 20...

Page 30: ... DIP is set to Demands AND OUT DSGN is set between 60 to 45 F ADJUST 35 to 100 F 2 0 to 38 0 C Default 70 F 21 0 C ADV BOILER INDOOR SECTION B The design indoor air temperature used in the heat loss calculation for the boiler zones Typically set to 70 F 21 0 C Note This item is only available when the DIP is set to Demands AND OUT DSGN is set between 60 to 45 F ADJUST 70 to 220 F 21 0 to 104 5 C D...

Page 31: ...ND DELAY SECTION D The time allowed for the control to receive a proof demand once the primary pump turns on Note Only available when PROOF DEMAND is set to F P ADJUST min 0 10 to 3 00 minutes Default 1 00 damper ADV CA PROOF DEMAND DELAY SECTION D The time allowed for the control to receive a proof demand once the C A contact turns on Note Only available if RELAY is set to DMPR AND Proof Demand i...

Page 32: ...n of the primary pump in combination with the DHW pump and whether or not DHW priority is required Note This item is only available when the Pump Sequencing DIP is set to Off DHW Mode 5 is only available if Mode 2 ADJUST OFF ON Default OFF ADV DHW SENSOR SECTION E Selects if a DHW sensor is to be used for DHW generation Note This item is only available when the Pump Sequencing DIP is to Off AND DH...

Page 33: ...t to OFF AND the Pump Sequencing DIP is set to OFF AND the Setback DIP is set to Setback ADJUST 1 2 3 4 Default 2 ADV DHW BOILER SECTION E The number of boilers used for indirect DHW generation Note This item is only available when DHW Mode is set to either 1 2 3 or 4 AND the Pump Sequencing DIP is set to Off ADJUST OFF 1 parallel no priority 2 parallel priority 3 pri sec no priority 4 pri sec pri...

Page 34: ...ating loads Note This item is only available when the DIP is set to Demands ADJUST UnOcc 35 to 100 F OFF 2 0 to 38 0 C OFF Default 60 F 15 5 C ADV WWSD UNOCCUPIED SECTION B Thesystem swarmweathershutdowntemperature during the Sleep and Unoccupied period Note This item is only available when the DIP is set Demands and the DIP is set to Setback ADJUST Primary 12 hr 12 to 180 hours OFF Default 96 hou...

Page 35: ...NESDAY SATURDAY Default SUNDAY USER INST ADV DAY OF THE WEEK SECTION J Set the day of the week TIME OFF DST1 DST2 Default OFF INST ADV DAYLIGHT SAVINGS TIME SECTION J Selects whether to use Daylight Savings Time The time is automatically adjusted if set to Mode 1 or 2 Note See page 17 for a description of DST Modes TIME JAN FEB MAR DEC Default JAN INST ADV MONTH SECTION J Set the current month of ...

Page 36: ...4 devices select MST1 to MST4 If the schedule is set on another tN4 device select MBR1 to MBR4 Note This item is only available if the Setback DIP is set to On and a tN4 device is present SCHD 24 hr 5 11 5 2 7DAY Default 24 hr USER INST ADV SCHEDULE TYPE SECTION K Select the type of schedule Note This item is only available when the Heat Schedule is set to MST1 through MST4 AND the Setback DIP is ...

Page 37: ... SECTION K Select the times for the scheduled events Note This item is only available when the Heat Schedule is set to CTRL or MST1 to MST4 AND the Setback DIP is set to On AND the Schedule Type is set to 5 2 Wake Default 6 00 AM UnOccupied Default 8 00 AM Occupied Default 6 00 PM Sleep Default 10 00 PM SCHD AM Wake UnOccSleep to 11 50 PM or to 23 50 USER INST ADV SATURDAY SECTION K Select the tim...

Page 38: ...cheduled events Note This item is only available when the Heat Schedule is set to CTRL or MST1 to MST4 AND the Setback DIP is set On AND the Schedule Type is set to 7 Day Wake Default 6 00 AM UnOccupied Default 8 00 AM Occupied Default 6 00 PM Sleep Default 10 00 PM SCHD AM Wake UnOccSleep to 11 50 PM or to 23 50 USER INST ADV THURSDAY SECTION K Select the times for the scheduled events Note This ...

Page 39: ...s the temperature units MISC 1 to 24 ADV NUMBER OF DEVICES SECTION M Number of tN4 devices connected to this tN4 bus MISC OFF SEL Default OFF ADV DEFAULT Press and hold the up and down buttons for 1 second to display DEFAULT SEL and load the default settings MISC 274 Software Version USER INST ADV TYPE Product number of this control Hold the Up button to view the software version Misc Miscellaneou...

Page 40: ...equipment manufacturer Max Heat The control has a function called Max Heat As long as there is a demand for heat the control operates in this mode for up to 24 hours or until the Test button is pressed tN4 devices operate to meet their occupied setting 5 F 3 C and display the MAX segment to indicate the Max Heat mode Use this mode to run the circulators during system start up to purge air from the...

Page 41: ...lt settings Operation continues normally Note To clear the error the access level must be set to Advanced and the settings in the Time menu must be checked VIEW CONTROL ERROR SCHEDULE The control failed to read the Schedule Menu settings and reloaded the factory default settings Operation continues normally Note To clear the error the access level must be set to Advanced and the settings in the Sc...

Page 42: ... and repair the problem as described in the Data Brochure D 070 The error message self clears once the error condition is corrected VIEW OUTDOOR SENSOR OPEN CIRCUIT Due to an open circuit the control failed to read the outdoor sensor As a result the control assumes an outdoor temperature of 32 F 0 0 C and continues operation Locate and repair the problem as described in the Data Brochure D 070 The...

Page 43: ...f but the damper proof demand remains after 4 minutes VIEW BOILER RETURN SENSOR SHORT CIRCUIT Due to an short circuit the control failed to read the boiler return sensor The control will continue to operate normally Locate and repair the problem as described in the Data Brochure D 070 The error message self clears once the error condition is corrected VIEW BOILER RETURN SENSOR OPEN CIRCUIT Due to ...

Page 44: ...customers Any representations or warranties about the Products made by Purchaser to its customers which are different from or in excess of the tekmar Lim ited Warranty are the Purchaser s sole responsibility and obligation Pur chaser shall indemnify and hold tekmar harmless from and against any and all claims liabilities and damages of any kind or nature which arise out of or are related to any su...

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