Lennox International Inc PVVC24ElO.7, PWC24E9.2, PWC302, PWC24E14.7 Partno, Modelno Filterareamin

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

If an installation 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.)
PWC 182	480 sq. in,
PWC 242	480 sq. in.
PWC302	480 sq. in.

THERMOSTAT

The room thermostatshouldbe located on an insidewall where it will not be subject todrafts, sun exposureor heat fromelectrical fixtures or appliances. Followthe manufacturer'sinstructions enclosedwith thethermostat for general installation procedures. Color codedinsulated wires (# !8 AWG)should be usedto connectthe thermostat to the unit.

POWERAND CONTROLWIRING

ELECTRICALCONNECTIONS

ALL WIRINGSHOULDBEDONEIN ACCORDANCEWITH NATIONALELECTRICALCODE,ANSI/NFPA No. 70 (LATEST EDITION). IN CANADACSA C22.2 Part 1 (LATESTEDITION),OR WITH LOCALCODES,WHERETHEY PREVAIL:

Usewiringwith a temperaturelimitationof 75°C rain. Runthe 208 or 230 volt, 60 hertzelectric powersupplythrough a fused disconnectswitch to the controlboxof the unit and connectas shownin the wiringdiagram located on the in- side of the control access panel.

The unit must be electricallygrounded in accordancewith local codesor in the absenceof localcodeswith the Na- tional Electric CodeANSI/NFPA No. 70 (latest edition)or CSA C22.2 Part 1 (latest edition).

Power supplyto the unit must be N.E.C. Class 1, and must complywith all applicable codes.A fused disconnect switch should be field providedfor the unit. The switch must be separatefrom all othercircuits. If any of the wire supplied with the unit must be replaced, replacement wire must be of the type shown on the wiring diagram.

Electricalwiring must be sized to minimumcircuitampacitymarked on the unit. USECOPPERCONDUCTORSONLY. Eachunit must be wired with a separatebranchcircuit and be properlyfused.

SEQUENCEOF UNIT OPERATION

COOLING- Whenthe thermostatis in the coolingmode,the 0 circuitis poweredwhichenergizesthe reversing valve. Upon coolingdemand,the thermostat closescircuitR to Y and G. ClosingR toY closesthe unit contactor,startingthe compressorandoutdoor fan. The thermostatautomatically closesRto G circuitwhichalsobrings on the indoor blower at the sametime. Uponsatisfying coolingdemand,the thermostat will openthe abovecircuitsand openthe main con- tactor, stoppingthe compressorand outdoorfan. If the unit is equippedwith a time delay, the blower will coritinueto operate for 90 seconds which improves system efficiency.

HEATING- Upon heating demand the thermostatclosescircuit R to Y closingthe unit contactor,starting the com- pressor and outdoor fan. The reversing valveis.no.t-energizedin the heating mode. The thermostatagainautomatical- ly brings on the indoorblower at the sametime. The secondstage of the thermostat closescircuftRto W closingthe unit sequencers, bring theauxiliary electric heaton. Upon satisfying heating demandthe thermostat opens abovecir- cuits and stops unit operation.

DEFROSTCYCLE- if outdoor ambient conditions are such that frost forms on the outdoorcoil, the defrost control monitors the need for and initiatesand terminates defrost cycles as neccessary to maintain system performance. The defrost controlis time/temperature initiated and temperatureterminatedwith a maximum defrost time (time-out) of

i 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.