BULLDOG SpaceKeeper Vertical – Installation Operation Maintenance Manual
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© Copyright 2013 CGC Group Inc Installation Operation Maintenance Manual is Subject to Change without Notice- Last Revised Oct 1, 2014
The CGC board has an optional input terminal strip that allows for two types of remote shutdown. These
are a) compressor shutdown and b) unit shutdown.
The advantage of these inputs is that many units can be connected in parallel and when powered by an
independent 24V AC signal, one or both of these actions can be implemented. Common uses are:
a.
Duty cycling for demand control
b.
Global night setback
c.
Heating-only mode during emergency power periods
The CGC controller is also set up so these shutdown functions can be initiated individually with on board
24V power. This capability allows unit or compressor shutdown based on a door switch, a light switch, or
occupancy switch. A separate 24V power supply is required if two or more units are being shutdown.
FAULT ALARM OUTPUT
The CGC board is provided with a fault alarm indication and output. The fault alarm relay provides
normally open and normally closed contacts for use in transmitting fault conditions. NOTE: The fault
alarm is energized for NORMAL, and de-energized for fault. As such if the unit is not powered, if the
board fuse is blown, or if the electronics are damaged, a fault condition will be indicated.
The fault relay is paralleled with the Fault LED which will be ON when no fault condition exists.
Other fault conditions are:
Hard lockout due to high or low pressure switch being open for 10 minutes or longer.
Hard lockout due to three high or low pressure shutdowns in a 24 hour period.
High level condensate for in excess of 15 minutes.
ALTERNATE FUNCTIONS
Dehumidification cycle – When provided with an appropriate thermostat/humidistat, as well as
dehumidification software and additional components, the CGC unit will provide space
dehumidification. This is an optional feature.
Two compressor units – All units larger than 5 tons include single speed belt drive fans. Twin tandem
compressors are standard on units 15 tons (SKV180) and larger, and optional on units between 6
(SKV070) and 12.5 (SKV150) ton units. These twin compressor units are controlled individually
through on board relays K4 and K6 (this is a specially programmed board that uses relay K6 to
activate the second compressor, rather than it being used to activate high fan speed). The control
algorithms for these types of units will alternate which compressor is activated first, thereby allowing
for equally distributed wear. Because tandem compressors share a refrigeration circuit, the standard
single compressor algorithms are used to monitor and protect the compressors.
