BULLDOG SpaceKeeper Vertical – Installation Operation Maintenance Manual
13
© Copyright 2013 CGC Group Inc Installation Operation Maintenance Manual is Subject to Change without Notice- Last Revised Oct 1, 2014
FAN OPERATION
1.
A call on “G” for fan on the thermostat terminal strip will cause the fan to operate continuously
on low fan speed through K5 on multi speed units.
2.
A call on “W” for heat on the thermostat terminal strip will also cause the fan to
operate on low speed. If the heating call is still present after a 10 minute period, the multi
speed units will switch the fan to high speed through Relay K6.
3.
A call on “Y” for cooling on the thermostat terminal strip will cause the fan on multi
speed units to advance to high speed through Relay K6.
4.
Fan operation will terminate whenever all calls are dropped.
5.
When the fan is operating at high speed, both relays are energized along with their
associated LED indicators.
Note: - 460 and 575 volt units and belt drive units are single speed and K5 is used as a pilot relay
operating a separate fan contactor.
Note: On belt drive units with dual compressors, Relay K6 is used to operate second compressor.
HEATING OPERATION
1.
A call on “W” for heat will activate the fan at low speed. It will also simultaneously energize
the heat relay K2 and its associated LED. The relay K2 will provide 24V AC fused power directly
to the heat valve.
COOL START UP
1.
A call on “Y” for cooling initiates a series of checks prior to the start up of the compressor.
These are:
a.
Power ON timer – Compressor operation is delayed for approximately 5 minutes after
restoration of power. This prevents all units from coming on line at the same time
when power is restored. It also prevents compressor jolting with intermittent power.
b.
Anti-Recycle timer – There is a 5-minute anti-recycle delay timer that allows the
refrigeration cycle to achieve pressure equalization so that the compressor is unloaded
upon start up.
c.
High Pressure Switch – The high refrigerant pressure switch must be closed prior to
start up. LED 11 will be ON. High pressure switch opens at 600 ± 10 psi and closes at
450 ± 10 psi.
d.
Low Pressure Switch – The low pressure switch operates primarily as a loss of charge
protector. It must be closed for compressor start up and its LED 12 will be ON. Upon
start up, the signal from the low pressure switch is ignored for 5 minutes. In some
situations, particularly when the unit is cold, the pressure switch will open during start-
