Field Wiring - Williamson-Thermoflo GWS-090E Manual

6 Field wiring

For your safety, turn off electrical power supply
at service entrance panel before making any
electrical connections to avoid possible electric
shock hazard. Failure to do so can cause severe
personal injury or death.
Wiring must be N.E.C. Class 1.
If original wiring as supplied with boiler must be
replaced, use only type 105 °C wire or equivalent.
Boiler must be electrically grounded as required
by National Electrical Code ANSI/NFPA 70-latest
edition.
Electrical installation must comply with:
1. National Electrical Code and any other national, state, provin-
cial or local codes or regulations.
2. In Canada, CSA C22.1 Canadian Electrical Code Part 1, and
any local codes.
Wiring connections
Boiler is shipped with controls completely wired, except spill switch
and vent damper. See wiring diagram on page 18. Circulator is
shipped loose, but wiring harness is pre-attached to the boiler.
Connect wires in circulator junction box.
Figure 9 Field wiring connections — service switch and thermostat (or end switch) provided by installer
The GWS-090E control module is polarity-sensitive. The hot and neutral wires must be connected to the correct leads.
A flashing POWER light usually indicates reversed polarity of 120 VAC lead wires.
Part Number 550-110-737/1108
GWS-090E Gas-Fired Water Boiler – Boiler Manual
Thermostat
1. Connect thermostat as shown on wiring diagram on boiler.
2. Install on inside wall away from influences of drafts, hot or
cold water pipes, lighting fixtures, television, sunrays or fire-
places.
3. If thermostat has a heat anticipator, set heat anticipator in ther-
mostat to match power requirements of equipment connected
to it. If connected directly to boiler, set per wiring diagram,
Figure 13, on page 18. For other devices, see manufacturer's
specifications. Also see instructions with thermostat.
Junction box (furnished)
1. Connect 120 VAC power wiring. See Figure 9.
2. Fused disconnect or service switch (15 amp. recommended)
may be mounted on this box. For those installations with local
codes which prohibit installation of fused disconnect or service
switch on boiler, install a 2 x 4 cover plate on the boiler junction
box and mount the service switch remotely as required by the
code.
Wiring multiple zones
See zone valve manufacturer's literature for wiring and application.
A separate transformer is required to power zone valves. Zoning
with circulators requires a relay for each circulator.
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