Application Brochure

ManualsBrandsTekmar ManualsHeating ControlsUniversal Reset Control - Two Mixing, Two Stage Boiler, DHW & Setpoint

A 374 - 03/09

- Application Brochure

Universal Reset Control 374

A 374

03/09

Features of the Universal Reset Control 374

Please refer to Essay E 005: Control Functions and Benefits for a detailed description of these features.

Application

The tekmar Universal Reset Control 374 is designed to maximize the comfort and efficiency provided by a

hydronic heating system. The control automatically adjusts the boiler and mix water temperatures that are

delivered to the heating system by using outdoor reset. The 374 control can control two separate on / off

stages (or one low / high fire) to provide outdoor reset while providing equal run time rotation of the boilers.

The 374 can operate two mixing devices, which can be either two variable speed injection pumps or two

floating action valves. The mixing devices can be used to supply two different reset water temperatures or

one reset and one setpoint water temperature to a space heating system. The 374 is capable of controlling

an indirect Domestic Hot Water (DHW) storage tank and setpoint load. The control has an internal timer,

which can have 2 events per day on a 24 hour, 5-1-1 day or 7 day schedule.

• Outdoor Reset

• Characterized Heating Curve

• Warm Weather Shut Down

• Boiler Outdoor Reset

• Boiler Differential (Automatic)

• Boiler Minimum Supply

• Boiler Post Purge

• Fire Delay

• Boiler Mass

• Boiler Enable

• DHW Boiler Reset Override

• DHW Priority

• DHW Priority Override

• DHW Post Purge

• DHW Mixing Purge

• Setpoint Boiler Reset Override

• Setpoint Enable

• Setpoint Priority

• Mixing Outdoor Reset

• Floating Action Output

• Variable Speed Output

• Boiler Protection

• System Protection

• Boiler Load Reset

• Pump / Integrated Exercising

• Internal Setback Timer

115 V (ac)

24 V (ac)

Universal Reset Control 374

Two Mixing, Two Stage Boiler, DHW & Setpoint

Menu Item

Boiler Demand

Mix 1 Demand

Mix 2 Demand

DHW Demand

Setpoint Demand

Summary of content (12 pages)

PAGE 1
- Application Brochure A 374 Universal Reset Control 374 03/09 Boiler Demand Mix 1 Demand Mix 2 Demand DHW Demand Setpoint Demand Menu Item Universal Reset Control 374 Two Mixing, Two Stage Boiler, DHW & Setpoint 115 V (ac) 24 V (ac) Features of the Universal Reset Control 374 Please refer to Essay E 005: Control Functions and Benefits for a detailed description of these features.
PAGE 2
© 2009 A 374 - 03/09 2 of 12 Z2 M Class 2 Transformer M Z1 24 V (ac) P2 Mix 1 Supply Sensor (S1) 082 see Essay E 021 V3 P4 Z3 M Mix 2 P3 Supply Sensor (S2) 082 V2 V4 P5 see Essay E 021 V1 P1 Outdoor Sensor (S3) 070 P6 A1 Boiler Supply Sensor (S4) 082 DHW Tank 03/09 A 374-1 tekmar Control Systems Ltd., Canada; tekmar Control Systems, Inc., U.S.A.; www.tekmarcontrols.com Head Office: 5100 Silver Star Road, Vernon, B.C.
PAGE 3
of 12 © 2009 A 374 - 03/09 N 24 V (ac) C R P4 P5 S4 S3 S2 S1 6 7 8 9 10 11 12 Do not apply power UnO Com Boil Out Com Mix1 Mix2 Sw 2.5A 1 2 3 4 5 5A Opn Cls1 Pwr Opn Cls2 1 Var1 Mix 2 Var2 5A 2.
PAGE 4
© 2009 A 374 - 03/09 4 of 12 Z4 T Z3 115 V (ac) T P3 S2 V2 C2 M 24 V (ac) Mix 2 Supply Sensor (S2) 082 Class 2 Transformer V5 ΔP Z2 T Concept Drawing This is only a concept drawing, not an engineered drawing. It is not intended to describe a complete system, nor any particular system.
PAGE 5
of 12 © 2009 A 374 - 03/09 N 24 V (ac) C Class 2 Transformer R 1 Com C 2 Opn 3 Cls C1 1 2 Opn 3 Cls C2 S3 S2 S1 5A 5A 5A 5A 5A 374 P2 Mix1 P2 P1 P3 Power Prim Mix2 L N P1 P3 N P4 Boiler Boiler #1 #2 Oﬀ Variable C Boiler Sensor Supply 10% Enable Return Relay 1 Floating 30% Enable R tekmar 500 Series Thermostats 7 8 1 2 R1 P5 optional required 6 5 4 3 03/09 A 374-2 tekmar Control Systems Ltd., Canada; tekmar Control Systems, Inc., U.S.A.; www.tekmarcontrols.
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© 2009 A 374 - 03/09 6 of 12 R2 P6 24 V (ac) Mix 1 Supply Sensor (S2) 082 R1 Class 2 Transformer see Essay E 021 V3 P4 tekmar 500 series thermostats V4 V2 V1 374 Pool Sensor (S1) 071 P3 R3 Outdoor Sensor (S4) 070 P2 150 DHW Tank A1 P1 Boiler Supply Sensor (S5) 082 03/09 A 374-3 tekmar Control Systems Ltd., Canada; tekmar Control Systems, Inc., U.S.A.; www.tekmarcontrols.com Head Office: 5100 Silver Star Road, Vernon, B.C.
PAGE 7
of 12 © 2009 A 374 - 03/09 N 24 V (ac) C R P4 P5 S2 S3 S5 S4 6 7 8 9 10 11 12 Do not apply power UnO Com Boil Out Com Mix1 Mix2 Sw 2.5A 1 2 3 4 5 5A Opn Cls1 Pwr Opn Cls2 1 Var1 Mix 2 Var2 5A 2.
PAGE 8
© 2009 A 374 - 03/09 8 of 12 Z5 M Class 2 Transformer Z4 M 24 V (ac) P2 V3 Mix 1 Supply Sensor (S1) 082 C1 M V5 ΔP Z6 M P3 V4 C2 M V2 V1 Z3 M Outdoor Sensor (S4) 070 Z2 M Z1 Tank M DHW tekmar 500 series thermostats A1 Boiler Supply Sensor (S3) 082 R1 P1 03/09 A 374-4 tekmar Control Systems Ltd., Canada; tekmar Control Systems, Inc., U.S.A.; www.tekmarcontrols.com Head Office: 5100 Silver Star Road, Vernon, B.C.
PAGE 9
of 12 © 2009 A 374 - 03/09 N Opn 2 Cls 3 C1 24 V (ac) C Class 2 Transformer Com C 1 R Com C 1 Opn 2 Cls C2 S2 S4 3 S1 S3 6 7 8 9 10 11 12 Do not apply power UnO Com Boil Out Com Mix1 Mix2 Sw 2.5A 1 2 3 4 5 5A Opn Cls1 Pwr Opn Cls2 1 Var1 Mix 2 Var2 5A 2.5A Concept Drawing This is only a concept drawing, not an engineered drawing. It is not intended to describe a complete system, nor any particular system.
PAGE 10
© 2009 A 374 - 03/09 10 of 12 T2 Z1 M T1 P8 ΔP Z4 M Mix 1 Supply Sensor (S4) 082 24 V (ac) V6 Class 2 Transformer T4 see Essay E 021 Z3 M Mix 2 P9 Supply Sensor (S5) 082 V2 V4 P7 see Essay E 021 V1 P4 Outdoor Sensor Alarm (A2) (S6) 070 Mechanical P5 Boiler Return Sensor (S7) 082 DHW Tank A1 268 Boiler Return Sensor (S2) 082 Boiler Supply Sensor (S3) 082 P1 Outdoor Sensor (S1) 070 P2 P3 03/09 A 374-5 tekmar Control Systems Ltd., Canada; tekmar Control Systems, Inc.
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of 12 © 2009 A 374 - 03/09 N 5A 5A 374 24 V (ac) C P6 R P7 S4 S5 S7 S6 P8 Mix1 P2 P4 P9 Power Prim Mix2 L N P1 P3 N Mix 1 Mix 2 Zone Valve Motor End Switches 5A Oﬀ Variable 374 5A 5A 5A 5A 5A 5A 5A 5A 5A Return C.A./ Alarm Relay 2 2 A2 C.A.
PAGE 12
Speciﬁcations The following are the recommended specifications for the Universal Reset Control 374. • The control shall be able to control the supply fluid temperature of two mixing devices. • The control shall have the option to directly operate two variable speed injection pumps or two mixing valves with floating action actuating motors. • The control shall have the ability to provide outdoor reset to each mixing system.