25
RSMD2R Technical Guide
TROUBLESHOOTING
Suction Pressure Transducer Testing
Suction Pressure Transducer Testing
for R410-A Refrigerant
The Evaporator Coil Temperature is calculated by converting
the Suction Pressure to Temperature. The Suction Pressure is
obtained by using the Suction Pressure Transducer, which is
connected into the Suction Line of the Compressor.
Use the voltage column to check the Suction Pressure Transducer
while connected to the RSMD2R Module(s). The VCCX2 and the
RSMD2R Module(s) must be powered for this test. Read
voltage with a meter set on DC volts. Place the positive lead
from the meter on the SP1/SP2 terminal located on the RSMD2R
Module(s) terminal block. Place the negative lead from the meter
on the ground (GND) terminal located adjacent to the SP1/SP2
terminal on the RSMD2R Module(s) terminal block. Use a
refrigerant gauge set and/or an accurate electronic thermometer
to measure the temperature or suction line pressure near where
the Suction Pressure Transducer is connected to the suction line.
Measure the Voltage at the SP1/SP2 and GND terminals and
compare it to the appropriate chart depending on the refrigerant
you are using. If the temperature/voltage or pressure/voltage
readings do not align closely with the chart, your Suction Pressure
Transducer is probably defective and will need to be replaced.
See the Suction Pressure Transducer, Pressure, Temperature, and
Voltage Chart for R410-A Refrigerant testing. The charts show
a temperature range from 20°F to 80°F. For troubleshooting
purposes, the DC Voltage readings are also listed with their
corresponding temperatures and pressures.
Table 4: Coil Pressure/Voltage/Temp for Suction
Pressure Transducers - R410-A Refrigerant
Suction Pressure
Transducer Coil
Pressure – Temperature – Voltage Chart for
R410-A Refrigerant
Temperature °F
Temperature
ºC
Pressure
PSI
Signal
DC V
olts
21.19
-6.1
80.94
1.8
24.49
-4.4
87.16
1.9
27.80
-2.8
93.39
2.0
30.99
-1.1
99.62
2.1
33.89
0.6
105.84
2.2
36.80
2.2
112.07
2.3
39.71
3.9
118.29
2.4
42.30
5.6
124.52
2.5
44.85
6.7
130.75
2.6
47.39
8.3
136.97
2.7
49.94
9.4
143.2
2.8
52.23
11.1
149.42
2.9
54.50
12.2
155.65
3.0
56.76
13.3
161.88
3.1
59.03
15
168.10
3.2
61.17
16.1
174.32
3.3
63.19
17.2
180.55
3.4
65.21
18.3
186.78
3.5
67.23
19.4
193.00
3.6
69.24
20.6
199.23
3.7
71.15
21.7
205.46
3.8
72.95
22.2
211.68
3.9
74.76
23.3
217.91
4.0
76.57
24.4
224.14
4.1
78.37
25.6
230.36
4.2
80.18
26.7
236.59
4.3
Summary of Contents for RSMD2R
Page 1: ...RSMD2R Technical Guide...
