Manual

PARTNO. ] 41194D094 ] DATE ] 4-15-94 ] SUPERSEDES ] NEW ] PAGE6 OF 10

If aninstallation is madein which it is more desirable tomount the filter exterior tothe unit, in the return duct work,or

otherwise, either the permanent filter suppliedor a disposable filter may be used. If a disposable filter is used, the

minimum area required is as follows:

MODELNO, FILTERAREA(MIN.)

PWC182 480 sq. in,

PWC242 480 sq. in.

PWC302 480 sq. in.

THERMOSTAT

The room thermostatshouldbe locatedonan insidewallwhereit will not be subject todrafts, sun exposureor heat

fromelectrical fixtures or appliances. Followthe manufacturer's instructions enclosedwith thethermostat for general

installation procedures. Color codedinsulated wires (# !8 AWG)should be usedto connectthe thermostat to the unit.

POWERANDCONTROLWIRING

ELECTRICALCONNECTIONS

ALL WIRINGSHOULDBEDONEIN ACCORDANCEWITH NATIONALELECTRICALCODE,ANSI/NFPANo. 70 (LATEST

EDITION).IN CANADACSA C22.2 Part 1 (LATESTEDITION),OR WITH LOCALCODES,WHERETHEY PREVAIL:

Usewiringwithatemperaturelimitationof75°C rain. Runthe 208or 230 volt,60 hertzelectric powersupplythrough

a fused disconnectswitch to thecontrolboxof the unit andconnectas showninthe wiringdiagram located on the in-

side ofthe control access panel.

The unitmust beelectricallygrounded in accordancewithlocal codesor in theabsenceof localcodeswith the Na-

tional Electric CodeANSI/NFPA No. 70 (latest edition)or CSAC22.2 Part 1 (latest edition).

Power supplyto the unitmust be N.E.C. Class1, and must complywith all applicable codes.A fused disconnect

switch should be field providedfor the unit. Theswitchmust be separatefrom all othercircuits. If any of the wire

supplied with the unit must be replaced, replacement wire must be of the type shown onthe wiringdiagram.

Electricalwiringmust be sized tominimumcircuitampacitymarked on theunit. USECOPPERCONDUCTORSONLY.

Eachunit must bewiredwith a separatebranchcircuitand be properlyfused.

SEQUENCEOF UNIT OPERATION

COOLING- Whenthe thermostatisinthecoolingmode,the0 circuitispoweredwhichenergizesthereversing valve.

Upon coolingdemand,the thermostat closescircuitR to YandG. ClosingR toY closesthe unit contactor,startingthe

compressorandoutdoor fan. Thethermostatautomatically closesRto Gcircuitwhichalsobrings onthe indoor blower

at the sametime. Uponsatisfying coolingdemand,the thermostat will openthe abovecircuitsand openthe main con-

tactor, stoppingthe compressorandoutdoorfan. If the unit is equippedwith a time delay, the blower will coritinueto

operate for 90 seconds which improves systemefficiency.

HEATING- Upon heating demand the thermostatclosescircuitRto Y closingthe unitcontactor,starting the com-

pressor andoutdoor fan. Thereversing valveis.no.t-energizedin the heating mode.Thethermostatagainautomatical-

ly brings on the indoorblower at the sametime. Thesecondstage of the thermostatclosescircuftRto W closingthe

unit sequencers, bring theauxiliary electric heaton. Upon satisfying heating demandthe thermostat opens abovecir-

cuitsand stops unit operation.

DEFROSTCYCLE- if outdoor ambient conditions are such that frost forms on theoutdoorcoil, the defrost control

monitors the need for andinitiatesandterminates defrost cycles as neccessary to maintain system performance. The

defrost controlis time/temperature initiated and temperatureterminatedwith a maximum defrost time (time-out) of

10 minutes. Time betweendefrost cycles is pre-set at 60 minute intervals at the factory, but can be field adjusted to

30, 80, or 90 minutes. Seeillustralion for field adjustment of defrost timing. For best performance in RegionIV, the

PWC242defrost interval should be adjusted to 30 minutes.