Quantech QCC2015CEE, Installation, Operation And Maintenance Manual, Page: 146 / 172

QUANTECH
146
Form QCC2-NM1
Issue Date: 5/20/2021
SECTION 9 – SERVICE AND TROUBLESHOOTING
Discharge air temperature sensor
J6-5 = +5 VDC regulated supply to sensor.
J6-8 = vdc input signal to the microboard.
See Table 29 for voltage readings that
correspond to specific discharge tem-
peratures.
J6-2 = drain (shield connection = 0 VDC)
Analog inputs – pressure
Refer to the unit wiring diagram. Pressure inputs are
connected to the microboard on plugs J7 and J9. These
analog inputs represent varying DC signals corre-
sponding to varying pressures. All voltages are in ref-
erence to the unit case (ground).
System 1 discharge and suction pressures will be con-
nected to J7 of the microboard. System 2 discharge and
suction pressure transducers will be connected to J9 of
the microboard.
The discharge transducers are optional on all units. If
the discharge transducers are not installed, no connec-
tions are made to the microboard and the discharge
pressure readout on the display would be zero.
The suction pressure transducers are standard on all
QCC2s. The suction pressure transducers have a range
of 0 to 400 psig. The output will be linear from 0.5 VDC
to 4.5 VDC over the 400 psig (27.5 barg) range.
The discharge transducers have a range from 0 psig to
650 psig. The output will be linear from 0.5 VDC to
4.5 VDC over the 650 psig (41.25 barg) range. All volt-
age readings are in reference to ground (unit case).
Voltage/Resistance Correlation
TEMP°F VOLTAGE RESISTANCE TEMP°C
0 1.71 25619 -18
2 1.78 24046 -17
4 1.85 22580 -16
6 1.93 21214 -14
8 2.00 19939 -13
10 2.07 18749 -12
12 2.15 17637 -11
14 2.22 16599 -10
16 2.30 15629 -9
18 2.37 14721 -8
20 2.45 13872 -7
22 2.52 13077 -6
24 2.59 12333 -4
26 2.67 11636 -3
28 2.74 10982 -2
30 2.81 10370 -1
32 2.88 9795 0
34 2.95 9256 1
36 3.02 8750 2
38 3.08 8276 3
40 3.15 7830 4
42 3.21 7411 6
44 3.27 7017 7
46 3.33 6647 8
48 3.39 6298 9
50 3.45 5970 10
52 3.51 5661 11
54 3.56 5370 12
56 3.61 5096 13
58 3.67 4837 14
60 3.72 4593 16
62 3.76 4363 17
64 3.81 4145 18
66 3.86 3941 19
68 3.90 3747 20
70 3.94 3564 21
72 3.98 3392 22
74 4.02 3228 23
76 4.06 3074 24
78 4.10 2928 26
80 4.13 2790 27