Manual

(2)When the cooling setpoint has been satisfied ......... :
The compressor and condenser fan will de-energize immediately.
The evaporator blower motor will have a delay off and will de-ener-
gize after 30 seconds.
Heat Mode (Heat Pump Only): Energized (R,G,Y)
De-energized (O)
(a) When high and low voltage have been applied to unit
for more than 3 minutes:
(1) On a call for heating ......... :
The compressor and condenser fan will energize (there will be a 3
minute delay on 4Ton model with anti-cycle timer). The evapora-
tor blower motor will have a delay on and will energize after 30 se-
conds. The delay on for the compressor and the condenser fan can
be by-passed by jumpering the test pins on the defrost control
board.
(2) When the heating setpoint has been satisfied ......... :
The compressor and condenser fan will de-energize immediately.
The evaporator blower motor will have a delay off and will de-ener-
gize after 30 seconds.
Defrost Mode:Energized (R,G,Y) De-energized (O) Defrost
Sensor Closed
(1)
On a call for defrost .........
When the defrost sensor c!oses in the heating mode,there is a 30,
60 or 90 minute delay before the defrost mode begins. This delay
is selected by the position of a jumper on the defrost board
In normal defrost mode, the following sequence will occur after the
set delay:
1. Condenserfan off.
2. Reversing valve energized to cooling and auxiliary electric
heat ("W" circuit) is energized.
3. After defrost sensor opens or a maximum of 10 minutes; the
condenser fan is energized immediately. After a 10-12 second
delay the reversing valve is then de-energized to the heat mode.
Electric strip heat is also de-energized except as required by ther-
mostat.
To check out the defrost mode, place jumper across the two tabs
marked "DF". This simulates the defrost sensor closing. The delay
can be by- passed by jum pering the test pins on the defrost control
board (this reduces the delay from 30 minutes to 7 seconds, from
60 minutes to 14 seconds and from 90 minutes to 21 seconds). In
the defrost mode the reversing valve will energize and the con-
denser fan will de-energize.
NOTE: If the jumper on the defrost delay selection is left in the "TEST"
mode, the board will default to 90 min. delay until power is off.
(2) When defrost has been completed .........
This condition will be maintained until the defrost sensor opens or
until the defrost mode operates for 10 minutes (or 2 seconds if test
pins are jumpered), whichever comes first.
Adding Accessories
Low/High Pressure Controls
This unit is equipped with extra !ow and high pressure ports located inside
the unit panel where the external high and low pressure ports are installed.
This allows for installation of high and low pressure controls or low ambi-
ent controls.
14. Operation
Scroll Anti-Cycle Timer (Where Applicable)
Single phase units with scroll compressors may be equipped with an anti-
cycle device which delays the start of the compressor in the event of a
power interruption. This equalizes pressure throughout the system and
prevents possible reverse rotation ofthe scroll compressor. Later produc-
tion scroll compressors are equipped with an anti-reverse device to pre-
vent the compressor from running backwards, so an anti-cycle timer is not
needed on these models.
CAUTION
Do NOT operate unit on cooling when the outdoor temperature isbe-
low 60°F. This is necessary to prevent possible damage to the com-
pressor.
Loss of Charge Pressure Switch
Scroll compressor bearing units are equipped with a low pressure switch
on the liquid line (high side) which has been installed to prevent system
damage due to a loss of charge. The switch will open and de- energize the
contactor if the high side pressure drops below the set point of the switch.
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