Tekmar Universal Reset Module 422 Wiring Brochure page 8

Wiring the Control
The following section explains how to wire individual
devices to the Universal Reset Module 422. For step by
step wiring refer to the terminal number on the right of
the page.
• • Before wiring ensure all power is turned off and take
all necessary precautions.
• • Install the supplied wiring compartment barriers by
sliding them into the grooves provided as to isolate the
low and high voltage wiring.
Wiring the Boiler
Terminals 51-52 are a dry contact. No power is available
from this switch. When the switch at 51-52 is closed the
boiler is to turn on. The boiler gets no power from these
terminals and the boiler must be wired to power as per the
manufacturers' directions.
These two terminals are typically connected to the boiler's
control circuit (commonly labeled as T-T). Connect these
two terminals directly to the boiler T-T connections.
Wiring the Demands (DHW, Setpoint)
• • To generate a DHW Demand a voltage between 20 and
260 V (ac) must be applied across the DHW Demand
terminals (53-54).
• • To generate a Setpoint Demand, a voltage between
20 and 260 V (ac) must be applied across the Setpoint
Demand terminals (55-56).
24 V (ac) is provided on terminals 57 and 58 to power the
DHW Demand and the Setpoint Demand. Each demand
uses approximately 0.1 VA.
Wiring tekmarNet
®
Terminals 59 and 60 provide a tN4 connection for tN4 devices
on either the Boiler or Mix 2 tN4 bus. Connect terminals
59 (C) and 60 (tN4) to the corresponding terminals on the
other tN4 device.
Polarity is important.
Ensure that terminal 59 (C) is connected to the C terminal
on the tN4 device and that terminal 60 (tN4) is connected
to the tN4 terminal on the tN4 device.
Wiring a Floating Action Actuator (Mixing Valve)
The control operates a 24 volt floating action (power open
/ power close) valve motor. Power is provided through an
internal transformer to a maximum of 8 VA. Connect the
wiring from the motor to terminals 61, 62, 63 where terminal
61 is 24 volt C (neutral) and terminal 62 is 24 V R (hot) for
opening and terminal 63 is 24 V R (hot) for closing.
© 2009 W 422 - 03/09
4 (tN4) Between Devices
• • Strip all wiring to a length of 3/8 in. or 10 mm for all
terminals.
• • Refer to the current and voltage ratings at the back
of this brochure before connecting devices to this
control.
T-T contacts on boiler
The example below shows the wiring to generate a DHW
Demand.
Switch (from Setpoint
Control or aquastat)
tN4 connection on
additional control
Valve motor
contacts
Com Opn Cls
8 of 12
Terminals 51-78
Terminals 51-52
Terminals 53-58
DHW Setpoint
Demand Demand
53 54 55 56
Terminals 59-60
C tN4
Terminals 61-63
C
61
Boiler
51 52
C R
24 V (ac)
57 58
C2 tN4
Boil/Mix2
59 60
Opn Cls
R R
62 63