Terminals 7 – 22 – tekmar 275 Boiler Control User Manual

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Non-Powered Output Connections

Terminals 7 – 22

Wiring the Modulating Boiler Outputs
The control provides a 0-10 V (dc) modulating output to
four modulating boilers.

• Polarity is important.

• Connect the + wire from boilers 1, 2, 3 and 4 to terminals
7, 9, 10 and 12 respectively.

• Connect the – wire from boilers 1 and 2 to terminal 8 and
from boilers 3 and 4 to terminal 11.

Note: Some modulating boilers may also require an on / off
signal in addition to the modulating signal. See terminals
13 to 20.

Wiring the T-T
(RELAY TYPE = Boiler

)

Terminals 13-14, 15-16, 17-18 and 19-20 are dry contacts.
No power is available from these terminals. These contacts
can be used to enable the modulating or on/off boiler. The
boiler must be wired to power as per the manufacturers’
directions.
These terminals are typically connected to the boiler’s
control circuit (commonly labeled as T-T). Connect these
terminals directly to the boiler T-T connections.

Wiring the Boiler Pumps
(RELAY TYPE = Boiler pump

)

Terminals 13-14, 15-16, 17-18 and 19-20 are dry contacts.
No power is available from these terminals. These contacts
can be used to turn on individual boiler pumps. Wire line
voltage to one side of the relay. The other side of the relay
goes to one side of the boiler pump and the remaining side
of the boiler pump goes to neutral.

Combustion Air / Alert Contact (C.A./Alert)
Terminals 21 and 22 are an isolated output in the control.
There is no power available on these terminals from the
control. These terminals are to be used as a switch to either
make or break power to the combustion air damper or alert
device. Since this is an isolated contact, it may switch a
voltage between 24 V (ac) and 230 V (ac).

Mod1

Mod2 Mod3

Mod4

Modulating

Boiler 1

Modulating

Boiler 2

Modulating

Boiler 3

Modulating

Boiler 4

Relay

Pump

Relay

Boiler

Pumps

120 V (ac)

24 to 230 V (ac)

Alert

C.A./

Alert

Combustion
Air

L or R

N or C