DIAGNOSTIC CHECK POINTS (con’t)
E4
Thermister inputs (measured with thermisters disconnected).
1 to 8
3 to 4.5 VDC – TE2 (Evaporator Thermister #2)
2 to 9
3 to 4.5 VDC – TC1 (Compartment Thermister #1)
3 to 10
3 to 4.5 VDC – TE1 (Evaporator Thermister #1)
4 to 11
3 to 4.5 VDC – TC3 (Compartment Thermister #3)
5 to 12
3 to 4.5 VDC – TE3 (Evaporator Thermister #3)
6 to 13
3 to 4.5 VDC – TC2 (Compartment Thermister #2)
7 to 14
3 to 4.5 VDC
Compressor Relay
(use E3 – 16 as common for measurements)
Com
115 VAC continuous (power line supply).
NO
115 VAC when compressor is running.
NC
Not
connected.
Alarm wires (check for continuity – these are contact closures only)
Black Common
Red
Normally closed (in no – alarm condition)
White
Normally open (in no – alarm condition)
Display Board
(IDB5D –4330)
E1
Display Board receive
1 +5VDC
2 data
signals
3 ground
E2
Futaba VFD display data connection
TE = Thermister / Evaporator -- Cut-in (39
°
F minimum) for Evaporator Temperature
TC = Thermister / Compartment – Compartment cut-out Temperature.
Thermister Tolerance
±
2 degrees.
15
