35
PTEC-M-1A
Heater Assembly With Power OFF
to the unit and heater:
1. Remove the heaters in question
and visually inspect the element
for broken condition.
2. Remove fuse link and test for
continuity (one time fuse) If open,
replace.
3. Remove wires from limit control
and test for continuity (automatic
reset). If open, replace.
Reversing Valve
Occasionally the reversing valve
may stick in the heating or cooling
position or in the mid-operation.
When stuck in the mid-position, part
of the discharge gas from the
compressor is directed back to the
suction side resulting in excessively
high suction pressure.
Component
Tests
WARNING!
To avoid possible electrical shock,
personal injury or death, disconnect
the power before servicing.
Air and Coil Thermistors With Power
Off:
1. Remove the indoor coil thermistor
leads from the circuit board.
2. Check the resistance of the
thermistor using an ohm meter
against the temperature-
resistance curve below.
3. If the thermistor does not test to
the curve properly, replace the
thermistor.
4. Repeat test for Outdoor Coil and
Indoor Air thermistors.
Check the operation of the valve by
starting the system and switching
the operation from COOLING to
HEATING and then back to
COOLING.
Important Note: Line voltage now
present. If the valve fails to change its
position, test the voltage (230 V or
265 V) at the valve coil connector
cap, while the system is on the
HEATING CYCLE.
Important Note: Set the thermostat all
the way counter-clockwise to prevent
the fan from suddenly coming on and
endangering the servicer’s hands.
Summary of Contents for PTEC-070
Page 22: ...PTEC M 1A 22 Refrigeration System PTEC Refrigeration System...
Page 54: ...PTEC M 1A 54 Schematic Diagrams PTEC and PTHC Condensate Pump One Stage Heat...
Page 55: ...55 PTEC M 1A Schematic Diagrams PTEC and PTHC Condensate Pump Two Stage Heat...
Page 56: ...PTEC M 1A 56 Schematic Diagrams PTEC and PTHC Power Vent One Stage Heat...
Page 57: ...57 PTEC M 1A Schematic Diagrams PTEC and PTHC Power Vent Two Stage Heat...
Page 58: ...PTEC M 1A 58 PTEC and PTHC Power Door One Stage Heat Schematic Diagrams...
Page 59: ...59 PTEC M 1A Schematic Diagrams PTEC and PTHC Power Door Two Stage Heat...
Page 60: ...PTEC M 1A 60 Schematic Diagrams PTEC and PTHC Condensate Pump with Power Vent One Stage Heat...
Page 61: ...61 PTEC M 1A Schematic Diagrams PTEC and PTHC Condensate Pump with Power Vent Two Stage Heat...
Page 62: ...PTEC M 1A 62 Schematic Diagrams Hydronic...
Page 63: ......
