Crankcase Heat; Pre-Start Check; Startup; Operation - Rheem RHPD Series Installation Instructions Manual

XIV. CRANKCASE HEAT
Crankcase heat is standard on 7
iliary switch on the compressor contactor turns off the heater
when the compressor is running.
XV. PRE-START CHECK
1. Is unit properly located and slightly slanted toward indoor
condensate drain?
2. Is ductwork insulated, weatherproofed, with proper spacing
to combustible materials?
3. Is air free to travel to and from outdoor coil? (See Figure 5.)
4. Is the wiring correct, tight, and according to unit wiring dia-
gram?
5. Is unit grounded?
6. Are field supplied air filters in place and clean?
7. Do the outdoor fan and indoor blower turn freely without
rubbing, and are they tight on the motor shafts?
8. Is unit elevated to allow for outdoor coil condensate drain-
age during heating operation and defrost?
XVI. STARTUP
1. Turn thermostat to "OFF," turn "on" power supply at discon-
nect switch.
2. Turn temperature setting as high as it will go.
3. Turn fan switch to "ON."
4. Indoor blower should run. Be sure it is running in the right
direction.
5. Turn fan switch to "AUTO." Turn system switch to "COOL"
and turn temperature setting below room temperature.
Unit should run in cooling mode after 5 minute compressor
on-delay has expired.
6. Are outdoor fans operating correctly in the right direction?
7. Is compressor running correctly?
8. Record the following after the unit has run some time.
A. Operating Mode _______________________________
B. Discharge Pressures (High) _________________ PSIG
C. Vapor Pressure at Compressors (Low) _________ PSIG
D. Vapor Line Temperature at Compressors _________ °F.
E. Indoor Dry Bulb _____________________________ °F.
F. Indoor Wet Bulb ____________________________ °F.
G. Outdoor Dry Bulb ___________________________ °F.
H. Outdoor Wet Bulb ___________________________ °F.
I. Voltage at Contactor ________________________Volts
J. Current at Contactors ______________________ Amps
K. Model Number ________________________________
L. Serial Number _________________________________
M. Location _____________________________________
N. Owner _______________________________________
O. Date ________________________________________
9. Turn thermostat system switch to "HEAT." Unit should stop.
Raise temperature setting to above room temperature. Unit
should run in heating mode after 5 minute delay. Auxiliary
heaters, if installed, will energize 30 to 50 seconds after the
initiation of a "W3" call.
10. Check the refrigerant charge using the instructions located
on compressor access panel cover. Replace service port
caps. Service port cores are for system access only and
will leak if not tightly capped.
11. Adjust discharge air grilles and balance system.
12. Check ducts for condensation and air leaks.
13. Check unit for tubing and sheet metal rattles.
14. Instruct the owner on operation and maintenance.
15. Leave "INSTALLATION" and "USE AND CARE" instruc-
tions with owner.
⁄ & 10 ton models. The aux-
1
2
XVII. OPERATION

COOLING MODE

With thermostat in the cool mode, fan auto and the room tem-
perature higher than the thermostat setting:
A. Indoor blower contactor is energized through thermostat
contact (G).
B. Compressor contactor is energized through thermostat con-
tact (Y1). A 5 minute short cycle delay is standard on this
unit. Compressor will start immediately if test pins on the
defrost board are shorted and released.
C. Reversing valve is de-energized in the cooling mode
through thermostat contact (B).
D. Economizer enthalpy control (if installed) controls operation
of first-stage cooling and positions fresh air damper to main-
tain mixed air temperature. Second-stage cooling operates
normally as required by second stage of thermostats.
E. The system will continue in cooling operation as long as all
safety controls are closed, until the thermostat is satisfied.

HEATING MODE

With thermostat in the heat mode, fan auto and the room tem-
perature lower than the thermostat setting:
A. Indoor blower contactor is energized through thermostat
contact (G).
B. Compressor contactor is energized through thermostat con-
tact (Y1). A 5 minute short cycle delay is standard on this
unit. Compressor will start immediately if test pins on the
defrost board are shorted and released.
C. Reversing valve is energized in the heating mode through
thermostat contact (B).
D. Economizer enthalpy control (if installed) is electrically
bypassed with the heat pump control relay during heating

operation.

E. Should the heat requirement be more than the heat pump
can supply, a portion of the electric heat accessory (if sup-
plied) is energized through thermostat contact (W3).
F. The system will continue in heating operation as long as all
safety controls are closed, until the thermostat is satisfied.
G. The unit will function in a defrost mode, reversing the refrig-
erant cycle to cooling and energizing the electric heat (if
supplied) as required through the defrost relay.
H. If the refrigerant system becomes inoperable during a need
for heating, the thermostat may be set to emergency heat
which will energize the electric heat (if supplied).
At initial start-up or after extended shutdown periods make
sure the crankcase heater is energized for at least 12 hours
before the compressor is started.
XVIII. AUXILIARY HEAT
The amount of auxiliary heat required depends on the heat
loss of the structure to be heated and the capacity of the heat
pump. It is good practice to install strip heat to maintain at least
60ºF indoor temperatures in case of compressor failure. The
auxiliary heat is energized by the second stage of the thermo-
stat. The amount of electric heat that is allowed to come on, as
determined by the output of the heat pump, may be controlled
by an outdoor thermostat.
WARNING
!
ONLY ELECTRIC HEATER KITS SUPPLIED BY THIS MAN-
UFACTURER AS DESCRIBED IN THIS PUBLICATION
HAVE BEEN DESIGNED, TESTED, AND EVALUATED BY A
NATIONALLY RECOGNIZED SAFETY TESTING AGENCY
FOR USE WITH THIS UNIT. USE OF ANY OTHER MANU-
FACTURED ELECTRIC HEATERS INSTALLED WITHIN THIS
UNIT MAY CAUSE HAZARDOUS CONDITIONS RESULTING
IN PROPERTY DAMAGE, FIRE, BODILY INJURY OR DEATH.
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