Operating instructions

14
Part Number 550-142-784/0812
GWA Series 2 Gas-Fired Water Boilers – Boiler Manual
5 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 rollout thermal fuse element wire as supplied
withboilermustbereplaced,type200°Cwireor
equivalentmustbeused.Ifother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 pages 21 & 22
forspark-ignitedpilotboiler.Circulatorisshippedloose,butwiring
harnessispre-attachedtotheboiler.Connectwiresincirculator
junctionbox.
Thermostat
1. Connectthermostatasshownonwiringdiagramonboiler.
2. Installoninsidewallawayfrominuencesofdrafts,hotorcold
waterpipes,lightingxtures,television,sunraysorreplaces.
3. If thermostat has a heat anticipator, set heat anticipator
in thermostat to match power requirements of equipment
Figure 11 Field wiring connections — service switch, DHW (if used) and thermostat (or end switch) provided by installer.
connectedtoit.Ifconnecteddirectlytoboiler,setfor0.4amps.
Forotherdevices,seemanufacturer’sspecications.Wiring
diagramonboilergivessetting forcontrol moduleandgas
valve.Alsoseeinstructionswiththermostat.
DHW (if used)
ConnectDHWaquastatasshowninwiringbelow.Economy
functionisn’tutilizedwithDHWinput.
R & C Connections (if used)
24Vacleadsshouldbeusedforpowerstealingthermostatsonly!
Junction box (furnished)
1. Connect120VACpowerwiring(Figure11).
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.
DO NOT connect directly from 3-wire zone
valves to the T-T terminals on the boiler
.
When using 3-wire zone valves, install an isolation
relay.Connectthezonevalveendswitchwiresto
theisolationrelaycoil.Connecttheisolationrelay
contact across the boiler T-T terminals. Failure to
comply can result in damage to boiler components
or cause unreliable operation, resulting in severe
property damage.