EngA C-TRAC2 Installation, Operation And Maintenance Manual page 32

A
QUICK CHECK FOR C-TRAC-2.1 NORMAL OPERATING SEQUENCE
Heat light should come 'ON'
Is C-TRAC-2 calling for heat? More
than 2 VDC on "HT and B"
YES

If heat light 'ON', 2 – 10 VDC on B and HT
is modulating signal

If <1 VDC heat is not being called on

Economizer will be at minimum position
(min. position is adjusted at pot 7)
Is internal time delay light on?
YES
Internal delay
light ON/OFF
Unit is in its control dead
RE: INTERNAL TIME DELAY LIGHT

If OFF, control is satisfied. Will not change
output.

If ON, control is not satisfied and will increase or
decrease the amount of heat, economizer or
cooling to try and satisfy.
The following is a flowchart covering many general operating/troubleshooting stiuations.
If a more detailed manual is needed, contact the nearest EngA factory.

Power OFF then on to 24 VAC to H and N

Dip switch 1 'ON' only. (removes all overides)
NO
NO
Cooling stages should cycle on
(as required)
YES
Check cooling
safety switches
band and is satisfied

If call is for cooling, heat light should
eventually go off (may take 30 min)

B and HT = 0 VDC

Is cooling light on?
YES
Controller is in mechanical cooling mode.
Is compressor ambient light on?
YES
Compressors should cycle
on as called for.
YES
Normal operation
Check pressure controls on refrigeration circuits
and other safeties. Is 24 V on C and does it pass
thru C-TRAC stages 1 to 5 (contacts closed)
NO

Neither heat or cool light on - Unit is in free
cooling mode 'B' and 'ED' = 0-10 VDC. Mix box
modulates

Is internal time delay light on?
NO
Page viii
C-TRAC2.1 MANUAL
NO
NO
NO
Outside temperature is
below L.A.C. set point
YES
March 1999 R1
Replace
C-TRAC if
no lights
ever come
on