Quick Setup Guide

© 2009 Q 402 - 06/09 2 of 4
Basic Installation (continued)
Connect the Low-Voltage Wiring
tN2 Thermostats
The House Control 402 requires the use of tN2 Thermostats.
They are polarity insensitive and are wired directly to the top of
the control.
Sensors
All three sensors (Mix, Boil and Outdoor) are included and must
be connected to the House Control 402. Refer to the sample
mechanical layout on Page 4 for proper sensor locations.
Calls
A call for heat can be given to the House Control through an
external dry switch or by applying 24 V (ac).
DHW Call is typically wired from the aquastat on an indirect DHW
tank. A DHW Call signals the control to target 180°F (82°C).
A Setpoint Call can be used for a number of applications.
Please refer to the D402 Manual for more information.
Zone Valves
The on-board zone valve outputs are for mixed water temperature
zones. Connect the C and R wires from each zone valve to C and
Vlv on the House Control. The House Control 402 supplies 24 V
(ac) power to each zone valve. End switches are not required.
Boiler
A boiler dry contact is provided for on/off boilers and is labelled
“Boiler”. If using a modulating boiler, wire it to the 0-10 V (dc)
output terminals labelled “Mod (dc)”. The Boiler dry contact may
not be required in this case.
Floating Action Mixing Output
If using a mixing valve, a 24 V (ac) actuating motor can be connected
directly to the House Control 402. Use a tekmar Actuating Motor
741 or equivalent.
tN4 Expansion
The tN4 Expansion terminals allow other tekmarNet
®
devices with
tN4 capability to be connected to the system. Some options include:
tN2 or tN4 Wiring Centers, Timer 033, User Switch 479.
Connect tN4 and C from each device to the corresponding tN4
and C terminals on the 402. Mix temperature devices connect to
the Mix Exp. terminals and Boiler temperature devices connect
to the Boil Exp. terminals.
Input Power
Ensure that the transformer has been correctly sized. See “Sizing
the External Transformer” in the Installation and Operation Manual
D 402 for more detailed information.
Connect the 24 V (ac) leads from the transformer to the C and
R terminals marked “Input Power” on the House Control.
Note that tN2 Thermostats draw approximately 2 VA each.
Attach the Cover
Replace the cover of the House Control 402. Fasten with the 2
screws provided as shown in Figure 6.
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Sizing the External Transformer:
Add up all the thermostat and zone valve loads (VA) connected
to the House Control. If using a mixing valve, include the
actuating motor VA draw (Floating Action column). The
transformer must have higher capacity than this total load.
++ +
2 VA
=
T-stats
+
Zone
Valves
+
Floating
Action
+
Control
=
Total Load
Menu
House Control 4
02
Item
Figure 6
Figure 5