SpaceKeeper Cons ole (SKC) – Ins tallation Operation Maintenance Manual
10
OPERATION
condition can be obs erved on the thermos tat connection LEDs . (Note: A heat
pump thermos tat may caus e this s cenario).
2. Revers e Cycle Call – Poorly located automatic changeover thermos tats (ie.
thermos tats mounted on a wall oppos ite a dis charge grill, or a thermos tat in a
doorway to outs ide) can trigger heating and cooling mode changes many times
an hour. The CGC controller has a 10-minute anti-mode change timer when
changing from cooling to heating operation. The controller will not accept a
change in mode until 10 minutes have elaps ed s ince termination of the
oppos ite call.
Thermostat Connections
The CGC control board has been des igned to operate with mos t standard 24V AC
thermos tats . Thes e thermos tats are powered directly from the CGC board and provide
s ignals to the appropriate terminals depending on the operation at hand - Heat (W),
Cool (Y), Fan (G) or Aux (A). While most present-day thermos tats are compatible withthe
CGC control board, there are others that may not work properly. The following shouldbe
checked for s atisfactory performance prior to ins tallation:
1. Heat Pump Thermos tat – Some heat pump units do not have heat relays
(therefore are not compatible with s tandard thermos tats) and require “Heat
Pump Thermos tats ”. Thes e thermos tats call for both heating and cooling on
one of the s ignal wires . Thes e thermos tats are completely incompatible with
CGC’s controller.
2. Mercury bulb thermos tat - This type is problematic but can be us ed.
Unfortunately, the anticipators are a problem. Heat anticipators mus t be in
s eries with a high current relay or valve to function, s o do not perform on an
electronic circuit. This will res ult in larger than normal temperature s wings .
The cool anticipator, if overs ized, can bleed enough current to indicate a
cooling call even after it has been terminated.
3. Battery powered thermos tats – Thes e thermos tats were developed as
replacements for old mercury bulb thermos tats that had 4 wire connections
while 24V electronic thermos tats required 5 wires. Thes e will work with a CGC
board, although CGC does not recommend them. They require periodic battery
replacement, which is something that s hould be avoided if poss ible.
4. Power s tealing thermostats – This type of thermostat is electronic and was
als o developed as a replacement for old mercury bulb thermos tats . Thes e too
are problematic in that they bleed a small amount of current down the s ignal
wires and this may be interpreted as a s ignal for heat or cool.
5. Triac s witched controllers – This is a commonly used s witching device and all
controllers tes ted to date have functioned flawless ly. CGC recommends that
