Boiler Manual - Weil-McLain

GV90+ gas-fired water boiler — Boiler ManualWiringFor your safety, turn off electrical power supply at serviceentrance panel before making any electrical connectionsto avoid possible electric shock hazard. Failure to do socan cause severe personal injury or death.Figure 66 Field wiring connections — service switchand thermostat (or end switch) providedby installerInstallation must comply with:National Electrical Code and any other national, state, provincial orlocal codes or regulations. In Canada, CSA C22.1 Canadian ElectricalCode Part 1, and any local codes. Boiler must be electrically grounded asrequired by National Electrical Code ANSI/NFPA 70-latest edition.Wiring must be N.E.C. Class 1. Boiler must be electricallygrounded as required by National Electrical Code ANSI/NFPA 70-latest edition.Wiring connectionsPower wiringTo replace wiring, order complete harness assembliesfrom Weil-McLain. If any original wiring as supplied withboiler must be replaced, and a harness is not immediatelyavailable, use only type 105°C wire or equivalent. Use thiswiring only as a temporary repair. Obtain a completeharness from Weil-McLain.Connect 120 VAC power wiring as shown in Figure 66. The junctionbox is located on the inside left jacket panel.Watch the polarity of the circuit when connecting the120 VAC power wiring. If the polarity is switched, theintegrated boiler control will lockout. The IBC willflash the POWER light to indicate this problem. See thetroubleshooting information beginning on page 75.Additional limit controlsWire additional limit controls (if used) as shown in Figure 67.Thermostat(s)Install thermostats on inside walls, away from influences of drafts,hot or cold water pipes, lighting fixtures, television, sun rays, or fireplaces.Follow instructions with thermostat. If it has a heat anticipator, set heatanticipator in thermostat to match power requirements of equipmentconnected to it (ignition control and gas valve, zone valve contacts,etc.). Wiring diagram on boiler gives setting for standard equipment(ignition control and gas valve).When using three-wire zone valves, take careto avoid mis-wiring. This can impose an additional24 volts across the boiler control circuitry. The IBCwill sense this problem and lockout. It will flash the POW-ER and TSTAT CIRC lights to indicate the problem. Seelabel on IBC for explanation of lockout conditions. Toverify before connecting to boiler, disconnect field thermostatwires at boiler. Place a voltmeter across the leads. Thenwatch the voltmeter as each zone is activated (by activatingzone thermostat). There should never be a voltage readingacross the two leads coming to the boiler. If you see a voltagereading, one or more zone valves is mis-wired.Carbon monoxide detectorFor Direct Exhaust units, a carbon monoxidedetector is required in the boiler room. Thecarbon monoxide detector must be wired onthe same electrical circuit as the boiler. ForDirect Vent units, a carbon monoxide detectorthat is wired on the same electrical circuit asthe boiler is strongly recommended.Figure 67 Wiring location for additional limit controlsThermostat wires are labeled “T-T” on boiler. Remove label beforeconnecting as shown in Figure 66. Route this wiring through the holein the upper left side jacket.For zoned systems, substitute the zone valve end switches or circulatorrelay contacts for the thermostat contact shown in Figure 66.56Part number 550-142-054/1211