Bard WG242 Installation Instructions Manual

Bard WG242 Installation Instructions Manual Manual pdf 36 page image

Manual 2100-365MPage 36 of 7430. SEQUENCE OF OPERATION –HEATINGOn a call for heat from the thermostat, the induced draftblower is energized. Once sufficient draft isestablished, the pressure switch contacts close and theignition system is energized. The direct spark ignitorwill be energized allowing gas to flow. At the sametime the main valve is energized, a 30-second blowerdelay timer is activated.After this delay, the heating speed blower relayenergizes. The blower will begin operating and remainin operation until the set delay time after the call forheat has been satisfied. (See Table 15 for selectableblower off time delays.) This timing sequenceguarantees blower on, blower off operation.This unit is equipped with a flame roll-out switch,which is wired in series with the control circuit. This isa manual reset switch and is used for the purpose ofpreventing possible fire hazard in the event of a systemmalfunction. If this switch has opened the controlcircuit, there could be a possible system malfunction.Some of the conditions that might cause a roll-out tooccur are blockage or sooting of primary heatexchanger, overfiring of furnace due to improper mainburner orifices or incorrect manifold pressure,insufficient combustion air, or installation deficiencieswith respect to return air duct design or sizing.Once the problem has been resolved, reset the switch bypressing down on the reset button on top of the switch.See Figure 17 for additional information.31. SEQUENCE OF OPERATION –COOLINGOn a call for cooling from the room thermostat, the highspeed blower relay will be energized as well as thecompressor contactor. Following termination of thecooling cycle, the blower motor will continue to run forone minute.See Figure 17 for additional information.The unit may be equipped with a low ambient controlfor lower outdoor temperature operation in the coolingmode. If equipped with this optional control thecondenser fan will not operate immediately uponcompressor start-up, and will cycle on and off until thecondensing pressure remains above PSIG.FIGURE 17SEQUENCE OF OPERATIONELECTRONIC BLOWER CONTROLNOITCA ESNOPSERMETSYS.taehrofsllactatsomrehT).dezigrenesilanimretW(•••••.dezigrenesirewolbrianoitsubmoC.dehsilbatsesiwolfriA.sekamhctiwsgnivorpriA.dezigrenesimetsysnoitingI.sthgilrenrubniamdnasnepoevlavsaGsinafgnitalucriceht,etelpmocsignimitnehW.snigebgnimityalednonaftaeH.deepstaehtadezigrene.taehrofllacsdnetatsomrehT •••.sesolcevlavsagdnadezigrene-edsimetsysnoitingI.gnimitegruptsopretfadezigrene-edsirewolbrianoitsubmoCsinafgnitalucriceht,etelpmocsignimitnehW.snigebgnimityaledffonaftaeH.dezigrene-ed.loocrofllacsnigebtatsomrehT).dezigrene-erslanimretYdnaG(••.dezigrenesirotcatnocgnilooC.gnimityalednonafloocretfadeepsloocnodezigrenesinafgnitalucriC.nafrofllacsnigebtatsomrehT).dezigrene-edsilanimretG(• dezigrene-edsinafgnitalucriC.snepo)tuolloremalf(timiL ••.sesolcevlavsagdnadezigrene-ederametsysnoitingidnatatsomrehTnarewolbrianoitsubmoC d .dezigreneeradeepstaehnafgnitalucrictuolloremalfro)teserotua(timiL.desolctiucric)teserlaunam(•••.gnimitegruptsoprofdezigrenesniamerrrewolbrianoitsubmoC.gnimitffoyaleddetcelesehtrofdezigrenesniamernafnoitalucricehT.semusernoitarepolamroN