IBC HPX 3, Installation And Operating Manual, Page: 39 / 68

6.8.4 Thermostat wiring
Thermostat-type control wiring will go to the J4 terminals (On Off Heat Cool). To make the control
signal a call for heating (no cooling), wire the J2 (Heat Cool) and J4 (On Off Heat Cool) terminals in
parallel as shown.
Jumper between J1 terminals (interlock)
Pigtail to HPX J2 terminals (heating-only mode)
24V Transformer
Thermostat wires send a 24V signal to HPX J4 terminals: W for heating-only thermostat,
Y for heat-pump t-stat.
Figure 17 HPX Series thermostat field wiring
For a load with multiple zones (e.g. thermostats controlling zone valves), use a zone control
module, or wire the end-switches of each zone valve in parallel and send a 24V signal through
them to the J4 terminals on the HPX controller.
Ensure that there are no disturbing influences on the call-for-heat lines. Most power-stealing
thermostats can be connected directly to the
HPX Series
terminals.
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6.8.4 Thermostat wiring