Djm2 Slaving From C-Trac; G-Trac2; For Direct C-Trac Control Of The G-Trac-2; Sensor Location - EngA C-TRAC2 Installation, Operation And Maintenance Manual

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DJM2 Slaving From C-TRAC

Occasionally reports are received where a C-TRAC, acting as the main temperature control
(with the DJM2 its slave) cycles from heat mode to free cool mode (neither heat nor cool light
on) then back to heat mode. This results in excessive temperature swings due to the time
delays as the C-TRAC changes modes. To reduce this ocurance:
Firstly, ensure the CONT, BMSS and BMSZ pots are correct as described in the DJM2
manual section X.
Secondly, if the above does not resolve the problem, adjust the C-TRAC COOLING
DEADBAND Pot #3 to number value eleven. Also access the C-TRAC Pot eleven on the
back of the C-TRAC and set it to number 2.
Thirdly, if the above steps do not resolve the issue, use an open sensor (contact the factory
for details).
Fourth, if after doing the above and reasonable control cannot be attained, contact the factory
about "Splitting" the C-TRAC and DJM2 apart.

G-TRAC2

The G-TRAC
slow operating ramp, hunting should be very little after the initial 15 minute start-up cycle.

For Direct C-TRAC Control of the G-TRAC-2

The G-TRAC, model 2.2 gives better control than previous versions.

Set C-TRAC cooling deadband pot 3 to 4 degrees higher than normal value.

Set C-TRAC heat envelope pot to position 1.5 (pot 11)

Heat may stay on due to G-TRAC2 integral timing, if the G-TRAC2 heat switch is left on when
the C-TRAC switches to mechanical cooling. Stage 1 mechanical cooling call should turn power
off to the G-TRAC2 terminal "HS" by opening relay contacts.

Sensor Location

Is the sensor located in a good sensing location? A good sensing location is where there is a high
volume of non stratified air, which is a good representation of the average temperature.

Mixed Air Dampers

If dampers are hunting excessively, adjust pot 3 (cooling deadband) to a wider dead band as per set up
sheet. (Adjust it towards 13.) Adjust the travel of "linkage" style actuators to maximum stroke (160ºF).

Possible C-TRAC2.1 Adjustments to Reduce Hunting

Lastly, select the next lower setting for the heat envelope pot (11). Do not set pot 11 below 1.5. Pot 11
works in conjunction with pot 3. The purpose of pot 11 is to allow an adjustment to compensate for the
"heat envelope" which is a characteristic of each heat exchanger and allows time for the heat
exchanger mass to gain or loose heat. Pot 11 is just a randomly selected number system and the
design selection is to set for a 5 to 6 degree deadband on the heating system. Set at 2 gives a wider
band; set at 5 gives a narrower band. Setting a wider band slows the control valve speed by opening
the centre band wider. Note that pot 3, the cooling deadband pot is marked in degrees. It should then
be slowly opened to a wider band (higher number) until the best control is achieved.
2 has special electronic circuitry designed to reduce hunting. As the
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C-TRAC2.1 MANUAL
G-TRAC 2 has a
March 1999 R1