Eprom Memory Indicator (Ee); Configuration Display; Troubleshooting Temperature Sensors - Daikin MicroTech II Operation And Maintenance Manual

OM 752-4

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
–40 (–40) 613
–31 (–35) 640
–22 (–30) 668
–13 (–25) 697
–4 (–20) 727
5 (–15) 758
14 (–10) 789
23 (–5) 822
32 (0) 855
41 (5) 889
50 (10) 924
59 (15) 960
68 (20) 997
77 (25) 1035
86 (30) 1074
95 (35) 1113
104 (40) 1153
°F (°C) Resistance in ohms
113 (45) 1195
122 (50) 1237
131 (55) 1279
140 (60) 1323
149 (65) 1368
158 (70) 1413
167 (75) 1459
176 (80) 1506
185 (85) 1554
194 (90) 1602
203 (95) 1652
212 (100) 1702
221 (105) 1753
230 (110) 1804
239 (115) 1856
248 (120) 1908
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