![Fig. 12 Ð Cooling Mode Operation](/images/new-backgrounds/34034/3403419x1.webp)
Fig. 12 Ð Cooling Mode Operation
C. Defrost
Defrost board (DB) is a time and temperature control, which includes a
Defrost mode is identical to Cooling mode, except outdoor- fan motor (OFM) stops and a bank of supplemental electric heat turns on to warm air supplying the conditioned space. Defrost mode is terminated when the DFT reaches 65 F.
VI. CHECKING COOLING AND HEATING CONTROL OPERATION
Start and check the unit for proper control operation as follows:
1.Place room thermostat SYSTEM switch in an OFF po- sition. Observe that blower motor starts when FAN switch is placed in ON position and shuts down when FAN switch is placed in AUTO position.
2.Place SYSTEM switch in COOL position and FAN switch in AUTO position. Set control below room temperature. Observe that compressor, outdoor fan, and indoor fan motors start. Observe that cooling cycle shuts down when control setting is satis®ed.
3.Place system switch in HEAT position. Set control above room temperature. Observe that compressor, outdoor fan,
Observe that heating cycle shuts down when control set- ting is satis®ed.
4.When using an automatic changeover room thermostat, place both SYSTEM and FAN switches in AUTO posi- tions. Observe that unit operates in Cooling mode when temperature control is set to call for cooling (below room temperature), and unit operates in Heating mode when temperature control is set to call for heating (above room temperature).
VII. MALFUNCTION
The
The lockout system can be reset by adjusting the thermostat to open the contacts (down for heating mode, up for cooling mode) deenergizing the
Unit is equipped with a
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