Control Input Check (Aquastat Sensor); Fluid Sensor Temperature To Resistance Table - Emerson Liebert iCOM Training And Service Manual

Control Input Check (Aquastat Sensor)

The iCOM control system may be supplied with the either the Glycool or Dual
Cooling option. These options are supplied with an additional sensor to provide an
input to the control board. This additional sensor measures either the chilled glycol
or chilled water temperature. The control input check allows the end user to better
troubleshoot the glycol or dual cooling type units. The sensor is located on the
entering glycol or chilled water line to the unit. The return air sensor is used as an
input to the unit control software program to calculate the needed capacity. This
optional sensor wired to Plug P7 on the unit control board. The chart that follows
can help to troubleshoot this circuit.
Use the table below to check the fluid thermistor sensor for accuracy. To read the
resistance value of the thermistor it must be electrically removed from the circuit.

Fluid Sensor Temperature to Resistance Table

Temperature
ºF
32ºF
34ºF
36ºF
38ºF
40ºF
42ºF
44ºF
46ºF
48ºF
50ºF
52ºF
iCOM
Aquastat Sensor
Resistance Temperature
Value Ohms
32,650
30,859
29,176
27,595
26,109
24,712
23,398
22,160
20,996
19,899
18,872
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Control Training and Service Manual
Resistance
ºF Value Ohms
54ºF 17,903
56ºF 16,990
58ºF 16,128
60ºF 15,315
62ºF 14,547
64ºF 13,823
66ºF 13,139
68ºF 12,492
70ºF 11,884
72ºF 11,309