C _ = BRN(COMMON=)
W1_4. - _VLO.[S_TE_P_2_.
Wl_ = VVHT_SZEPjL ....
TO
UNIT POWER
WIRING
FUSE BLOCK
F3_[YEL
LI_.--_ _
q
I
I
i CONTACTOR 2
. YEL YEL
I
I
J
CONTACTOR 1
-BRN
:l °l
AYTQ:LIM!T BLK
C00014
Fig. 15--Accessory Electric Heater Wiring
FOR 208/230-V
The motor leads are color-coded as lollows:
3-SPEED 2-SPEED
black = high speed black = high speed
blue = medium speed
red = low speed red = low speed
To change the speed of the blower motor IBM), remove the fan
motor speed leg lead li"om the indoor (evaporator) fan relay (IFR)
and replace with lead Ik)r desired blower motor speed, lnsuh_te the
removed lead to (n,oM colztact with chassis parts.
FOR 460-V MOTORS
The motor leads are color coded as Ik)llows:
3-SPEED (060 ONLY) 2-SPEED
black = high speed black = to purple
yellow = line
orange = medium speed purple = to black
blue = low speed red = line
To change the speed of the blower motor IBM) from low speed to
high speed, remove the red lead li"om the indoor-fan relay (A1FR).
Insulate the red lead to avoid contact with any chassis parts.
Separate the black lead li"om the purple lead. Connect the black
lead to the IFR. Insulate the purple lead to avoid contact with any
chassis parts.
Step S--Unit Controls
All compressors have the R)llowing internal-protection controls.
HIGH-PRESSURE RELIEF VALVE
This valve ()pens when the pressure dilli_rential between the low
and high side becomes excessive.
COMPRESSOR OVERLOAD
This overload interrupts power to the compressor when either the
current or internal temperature become excessive, and automati-
cally resets when the internal temperature drops to a salt: level.
This overload may require tap to 60 minutes (or longer) to reset;
therefiwe, if the internal overload is suspected of being open,
disconnect the electrical power to the unit and check the circuit
through the overload with an ohmmeter or continuity tester.
Step 6--Sequence of Operation
FAN OPERATION
The FAN switch on the thermostat controls indoor l_m operation.
When the FAN switch is placed in the ON position, the IFR
(indoor-lhn relay) is energized through the G terminal on the
thermostat. The normally-open contacts close, which then provide
power to the indoor (evaporator) fan motor (IFM). The IFM will
run continuously when the FAN switch is set to ON.
When the FAN switch is set to AUTO, the thermostat deenergizes
the IFR (provided there is not a call lor cooling). The contacts open
and the 1FM is deenergized. The IFM will be energized only when
there is a call lot cooling, or if the unit is equipped with accessory
electric heat, the indoor-fan motor will also run while the acces-
sory electric heat is energized.
NOTE: 50ZP060 unit is equipped with a time-delay relay. On this
unit, the indoor fan remains on lkw 30 seconds after G or Y is
deenergized.
COOL1NG
On a call lbr cooling, the compressor contactor (C) and the 1FR are
energized through the Y and G terminals of the thermostat. On
units with a compressor time-delay relay, there is a 5-minute (+ 45
sec) delay between compressor starts. Energizing the compressor
contactor supplies power to the compressor and the outdoor
(condenser) fan motor (OFM). Energizing the IFR provides power
to the 1FM.
When the need lor cooling has been satisfied, the OFM, compres-
sor, and 1FM (FAN on AUTO) am deenergized. If the unit is
equipped with a 30-second delay, the indoor fan will remain
energized Ibr 30 seconds alter the compressor is deenergized (060
unit only).
HEATING
If accessory electric heaters are installed, on a call lor heat the
thermostat energized the W relay which energizes the electric
heaters. The IFR is energized which starts the indoor-fan motor. If
the heaters are staged, W2 is energized when the second stage of
heating is required. When the need Ii)r heating is satisfied, the
heater and 1FM are deenergized.
II
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