Application Brochure

ManualsBrandsTekmar ManualsBoiler/DHW ControlsOutdoor Reset Boiler Control - One Stage Boiler

Table Of Contents

1 of 8

- Application

Boiler Control 256

A 256-1

05/00

Note:

This is only a concept drawing. The designer must determine whether this application will work in his system and must ensure compliance with

code requirements. Necessary auxiliary equipment, isolation relays (for loads greater than the specified tekmar internal relay ratings), and other safety

and limit devices must be added.

Mechanical

Outdoor

Sensor (S2) 070

Class II

Transformer

120 V (ac)

24 V (ac)

∆P

Boiler

Sensor

(S1) 071

256

Electrical

P1 = Boiler Pump

S1 = Boiler Sensor 071

S2 = Outdoor Sensor 070

U1 = tekmar Timer 031 (optional)

V1 = Balancing Valve or Pressure Bypass Valve

Boiler

256

Boiler

R+

C-

Power

Do not apply power

UnO

Out

Boil

Com

24 V (ac)

120 V (ac)

Class II

Transformer

Summary of content (8 pages)

PAGE 1
- Application A 256-1 05/00 Boiler Control 256 Mechanical 256 Outdoor Sensor (S2) 070 Class II Transformer 24 V (ac) 120 V (ac) T T T Boiler Sensor (S1) 071 T P1 ∆P V1 Electrical 5A 256 Do not apply power 1 2 3 4 Boil Out Com UnO P1 = Boiler Pump S1 = Boiler Sensor 071 S2 = Outdoor Sensor 070 U1 = tekmar Timer 031 (optional) V1 = Balancing Valve or Pressure Bypass Valve 5 6 7 8 9 Boiler Sw S2 Power T R+ C- U1 Boiler S1 P1 Class II Transformer 24 V (ac) C R 120 V (ac) Note: This
PAGE 2
A 256-1 05/00 System Operation The Boiler Control 256 provides partial or full outdoor reset to four (or more) thermostatic radiator valve zones. Constant circulation to the system is provided by the boiler pump (P1). The boiler operates at the required temperature in order to satisfy the load. Heat Source Details The heat source can be either a high mass or low mass non-condensing or low temperature boiler. Piping Details Thermostatic radiator valve (TRV) zones are piped into the boiler loop.
PAGE 3
- Application A 256-2 05/00 Boiler Control 256 Mechanical 256 Outdoor Sensor (S2) 070 Class II Transformer 24 V (ac) 120 V (ac) R1 Z2 Z3 Z1 M M M T2 T3 T1 Boiler Sensor (S1) 071 Electrical 5A P1 256 Do not apply power 1 2 3 4 5 6 7 8 9 Boil Out Com UnO P1 = Boiler Pump R1 = Relay 003 S1 = Boiler Sensor 071 S2 = Outdoor Sensor 070 T1, ..., T3 = Thermostats U1 = tekmar Timer 031 (optional) Z1, ...
PAGE 4
A 256-2 05/00 System Operation The Boiler Control 256 provides partial or full reset to three (or more) boiler zones. The boiler is operated at the temperature required in order to satisfy the load. Heat Source Details The heat source can be either a high mass or low mass non-condensing or low temperature boiler. Piping Details Thermostat controlled zone valves are piped into the boiler loop. The boiler pump (P1) provides circulation through these zones when heat is required.
PAGE 5
- Application A 256-3 05/00 Boiler Control 256 Mechanical 256 Outdoor Sensor (S2) 070 Class II Transformer 24 V (ac) 120 V (ac) R2 R1 A2 Z3 Z2 M M T3 Z1 A1 M T2 T1 DHW Tank P2 Boiler Sensor (S1) 071 P1 5A Electrical 256 Do not apply power 1 2 3 4 A1 = DHW Aquastat A2 = DHW High Limit Aquastat P1 = Boiler Pump P2 = DHW Pump R1, R2 = Relay 003 S1 = Boiler Sensor 071 S2 = Outdoor Sensor 070 T1, ..., T3 = Thermostats U1 = tekmar Timer 031 (optional) Z1, ...
PAGE 6
A 256-3 05/00 System Operation The Boiler Control 256 provides partial reset to three (or more) boiler zones. The supply of heat to an indirect Domestic Hot Water (DHW) tank is controlled through an external relay. The boiler operates at the required temperature in order to satisfy the loads. Heat Source Details The heat source can be either a high mass or low mass non-condensing boiler. Piping Details Thermostat controlled zone valves are piped into the boiler loop.
PAGE 7
- Application A 256-4 05/00 Boiler Control 256 Mechanical 256 Outdoor Sensor (S2) 070 Class II Transformer 24 V (ac) 120 V (ac) R4 A2 R1 R2 T1 Z1 Z2 R3 T2 Z3 A1 T3 DHW Tank P1 Boiler Sensor (S1) 071 5A Electrical 1 2 3 4 Boil Out Com UnO A1 = DHW Aquastat A2 = DHW High Limit Aquastat P1 = DHW Pump R1, ..., R4 = Relay 003 S1 = Boiler Sensor 071 S2 = Outdoor Sensor 070 T1, ..., T3 = Thermostats U1 = tekmar Timer 031 (optional) Z1, ...
PAGE 8
A 256-4 05/00 System Operation The Boiler Control 256 provides partial reset to three (or more) zones. The supply of heat to an indirect Domestic Hot Water (DHW) tank is controlled through an external relay. The boiler operates at the required temperature in order to satisfy the loads. Heat Source Details The heat source can be either a high mass or low mass non-condensing boiler. Piping Details Thermostat controlled zone pumps are piped into the boiler loop.