Step four — electrical connections to the control, Terminals 25 - 31 – tekmar 275 Boiler Control User Manual
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© 2012 275_D - 11/12
Step Four — Electrical Connections to the Control
General
The installer should test to confirm that no voltage is present at any of the wires. Push the control into the base and slide
it down until it snaps firmly into place.
Powered Input Connections
Terminals 25 - 31
115 V (ac) Power
Connect the 115 V (ac) power supply to the Power L and
Power N terminals (25 and 26). This connection provides
power to the microprocessor and display of the control.
Boiler Demand
To generate a Boiler Demand, a voltage between 20 V (ac)
and 260 V (ac) must be applied across the Boiler Demand
terminals (27 and 28).
DHW
Demand
To generate a DHW Demand, a voltage between 20 V (ac)
and 260 V (ac) must be applied across the DHW/Setp and
Com Dem terminals (29 and 30). The Pump Sequencer
DIP Switch must be set to Off and DHW MODE must be
set to 1 through 5.
Setpoint Demand
To generate a Setpoint Demand, a voltage between 20 V
(ac) and 260 V (ac) must be applied across the DHW/Setp
and Com Dem terminals (29 and 30). The DHW MODE
must be set to OFF.
Proof Demand
To generate a Proof Demand, a voltage between 20 V (ac)
and 260 V (ac) must be applied across the Pr. Dem and
Com Dem terminals (31 and 30).
Energy Management System (EMS)
To generate an external input signal from an Energy
Management System (EMS), either a 0 to 10 V (dc) or 2
to 10 V (dc) signal must be applied 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.
N
L
25
26
Power
L
N
115 V (ac)
Dem
Dem
/Setp
Pr.
Com
DHW
31
30
29
20 to 260
V (ac)
L
N
Demand
Boiler
28
27
20 to 260
V (ac)
L
N
Dem
Dem
/Setp
Pr.
Com
DHW
31
30
29
20 to 260
V (ac)
L
N
Dem
Dem
/Setp
Pr.
Com
DHW
31
30
29
20 to 260
V (ac)
L
N
+
-
Out
Com
3
2
0-10 V (dc)
or
2-10 V (dc)
+
-
OR
+
-
Out
Com
3
2
0 - 20 mA
or
4 - 20 mA
+
-
500
Ω
Resistor