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40 www.DaikinApplied.com
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EPROM Memory Indicator (
ee
)
The EPROM Memory Indicator occurs when an unusual electrical event has scrambled
the EPROM memory within the controller board. In the event that this happens, the
controller board must be replaced.
Configuration Display (
--
)
The Configuration Display occurs when the display file “**.cfg” is incorrect or has not
been downloaded with the appropriate file from service tools.
Troubleshooting Temperature Sensors
The UVC is configured to use passive positive temperature coefficient (PTC) sensor
whose resistance increases with increasing temperature. The element has a reference
resistance of 1035 ohms at 77°F (25°C). Each element is calibrated according to the
tables shown.
Use the following procedure to troubleshoot a suspect sensor.
1.
Disconnect both sensor leads from the UVC.
2.
Using some other calibrated temperature sensing device, take a temperature
reading at the sensor location.
3.
Use the temperature reading from Step 2 to determine the expected sensor
resistance from Table 22.
4.
Using a calibrated ohmmeter, measure the actual resistance across the two sensor
leads.
5.
Compare the expected resistance to the actual resistance.
6.
If the actual resistance value deviates substantially (more than 10%) from the
expected resistance, replace the sensor.
Table 22: Temperature versus resistance
°F (°C)
Resistance in ohms
°F (°C)
Resistance in ohms
–40 (–40)
613
113 (45)
1195
–31 (–35)
640
122 (50)
1237
–22 (–30)
668
131 (55)
1279
–13 (–25)
697
140 (60)
1323
–4 (–20)
727
149 (65)
1368
5 (–15)
758
158 (70)
1413
14 (–10)
789
167 (75)
1459
23 (–5)
822
176 (80)
1506
32 (0)
855
185 (85)
1554
41 (5)
889
194 (90)
1602
50 (10)
924
203 (95)
1652
59 (15)
960
212 (100)
1702
68 (20)
997
221 (105)
1753
77 (25)
1035
230 (110)
1804
86 (30)
1074
239 (115)
1856
95 (35)
1113
248 (120)
1908
104 (40)
1153
Summary of Contents for MicroTech II
Page 2: ......
