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ManualsBrandsTekmar ManualsBoiler/DHW ControlsBoiler Control - One tN4, Four Stage Boiler & DHW / Setpoint

A 274

01/12

- Application Brochure

Boiler Control 274

Electrical

Application A 274-1

System Description: The Boiler Control 274 controls up to four On/Off boilers to provide outdoor reset for the space heating

zones. The boilers are piped in primary-secondary and the primary pumps are controlled by the 274 to allow for redundant

pumping capacity as well as equal run time rotation. The 274 has an alert contact which closes when a pump error occurs.

A flow proof device is used to prove flow from the pumps to the 274.

Mechanical

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. It is up to the

system designer to determine the necessary components for and configuration of the particular system being designed, including additional equipment, isolation relays

(for loads greater than the control’s specified output ratings), and any safety devices which in the judgement of the designer are appropriate, in order to properly size,

configure and design that system and to ensure compliance with building and safety code requirements.

S2F1

120 V (ac)

274

P4 P5

S1 = Outdoor Sensor 070

S2 = Boiler Supply Sensor 082

P1 = Primary Pump

P2 = Stand-by Primary Pump

P3,...,P6 = Boiler Pumps

F1 = Flow Proof Device

A1 = Alert

Boiler

DHW

Sup

Do not apply power

274

720

Power

tN4 Com Out Boil Com BRet/ Relay

910

Relay

11 12

Relay

13 14

Relay

15 16

C.A./

Alert

21 22

Boiler

Demand

23 24

DHW

/Setp

Com

Dem

Pr.

Dem

Prim

DHW

/P2

Boiler

115 V (ac)

Demands

Setback

Oﬀ

EMS

Rotate

Fixed Last

Pump Sequencer

Exercise

Oﬀ

Fixed Lead

First On / Last Oﬀ

First On / First Oﬀ

274 Switch Settings:Essential Control Settings:

Mode = 1

Summary of content (8 pages)

PAGE 1
- Application Brochure A 274 01/12 Boiler Control 274 Application A 274-1 System Description: The Boiler Control 274 controls up to four On/Off boilers to provide outdoor reset for the space heating zones. The boilers are piped in primary-secondary and the primary pumps are controlled by the 274 to allow for redundant pumping capacity as well as equal run time rotation. The 274 has an alert contact which closes when a pump error occurs. A flow proof device is used to prove flow from the pumps to the 274.
PAGE 2
Application A 274-2 System Description: The Boiler Control 274 controls two On/Off boilers to provide outdoor reset for the space heating zones. The boilers are piped in reverse return, parallel primary-secondary and the boiler pumps are controlled by the 274 to allow post purging of the boilers after they have shut off. The 274 also controls a DHW pump. This system can provide DHW priority over space heating to provide faster DHW tank recovery.
PAGE 3
Application A 274-3 System Description: The Boiler Control 274 controls two On/Off boilers to provide DHW and outdoor reset operation for the space heating zones. The 274 receives a 0-10 V(dc) or 2-10 V(dc) signal from an EMS system which creates a target temperature for the control, which then stages the boilers as required. The 274 also controls a DHW pump. This system can provide DHW priority over space heating to provide faster DHW tank recovery.
PAGE 4
Application A 274-4 System Description: The Boiler Control 274 controls two, 2 stage boilers to provide DHW and outdoor reset for the space heating zones. The tN4 Gateway 483 allows for remote monitoring of the 274 and access to the tN4 system through a web browser. The 274 receives a boiler demand over the tN4 boiler bus from the tN4 thermostats. A 161 Setpoint control is used to create a DHW demand over the tN4 network. This allows for both DHW production and the use of the pump sequencer function.
PAGE 5
Application A 274-5 System Description: The Boiler Control 274 controls one 3 stage boiler and a pump to provide outdoor reset for the space heating zones. The boiler is piped in primary secondary and the 274 controls the boiler pump to allow post purging of excess heat from the boiler to the system. The zone valve end switches provide a 24V(ac) powered demand to the 274 control in order to create a call for heat. The 274 also controls a DHW pump.
PAGE 6
Application A 274-6 System Description: The Boiler Control 274 controls two, Lo/Hi fire boilers to provide setpoint operation for the dedicated DHW tank. When a valid DHW Demand is present from the DHW Sensor, the DHW pump relay turns on. The DHW relay in this mode is used as the DHW recirculation pump and operates continuously in the occupied period and cycles with the DHW demand in the unoccupied period. The boilers are sequenced based only on the DHW Sensor. The Boiler supply sensor is not required.
PAGE 7
Application A 274-7 System Description: The Boiler Control 274 operates two On/Off boilers and boiler pumps piped in primary-secondary, providing outdoor reset for the space heating zones. When a valid DHW Demand is present, the DHW pump P3 turns on. The boiler supply temperature for the indirect tank is measured by sensor S3. There are two boiler target temperatures, one for the heating system (Boil TARG) and one for the indirect DHW system (DHW TARG).
PAGE 8
Speciﬁcations: The following are the recommended specifications for the Boiler Control 274 • The control shall be able to adjust the number of boilers required to operate during a call for domestic hot water heating. • The control shall have the ability to calculate the boiler’s target temperature based on outdoor reset. • The control shall have the ability to set the boiler’s target temperature using an adjustable setpoint.