Manual 2100-420H
Page 29 of 34
CHECKING TEMPERATURE SENSOR
1. Disconnect temperature sensor from board and from
outdoor coil.
2. Use an ohmmeter and measure the resistance of the
sensor. Also use ohmmeter to check for short or
open.
3. Check resistance reading to chart of resistance use
sensor ambient temperature. (Tolerance of part is ±
10%.)
4. If sensor resistance reads very low, then sensor is
shorted and will not allow proper operation of the
heat pump control.
5. If sensor is out of tolerance, shorted, open, or reads
very low ohms then it should be replaced.
SOLID STATE HEAT PUMP CONTROLTROUBLESHOOTING PROCEDURE
1. NOTE: A thorough understanding of the defrost
cycle sequence is essential. Review that section
earlier in this manual prior to troubleshooting the
control. Turn on AC power supply to unit.
2. Turn thermostat blower switch to “fan on” – the
indoor blower should start. (If it doesn’t,
troubleshoot indoor unit and correct problem.)
3. Turn thermostat blower to “auto” position. Indoor
blower should stop. NOTE: Many models have a
1-minute blower time delay on “off” command;
wait for this to time-out.
4. Set system switch to “heat” or “cool”. Adjust
thermostat to call for heat or cool. The indoor
blower, compressor and outdoor fan should start.
NOTE: If there was no power to 24 volt transformer,
the compressor and outdoor fan motor will not start for
5 minutes. This is because of the compressor short
cycle protection. TABLE 6
TEMPERATURE (F) VS RESISTANCE (R) OF TEMPERATURE SENSOR
FR FR FR F R
0.52- 0.42- 0.32- 0.22- 0.12- 0.02- 0.91- 0.81- 0.71- 0.61- 0.51- 0.41- 0.31- 0.21- 0.11- 0.01- 0.9- 0.8- 0.7- 0.6- 0.5- 0.4- 0.3- 0.2- 0.1- 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.70.8 0.9 0.01 0.11 0.21
178691 990091 585381 813771 982171 784561 409951 925451 553941 473441 675931 659431 605031 912621 980221 801811 272411 575011 010701 475301 062001 46079 18939 80019 93188 17358 99628 12108 23677 03257 01927 07607 70586 81466 99346 94426 56506 54785
0.31 0.41 0.51 0.61 0.71 0.81 0.91 0.02 0.12 0.22 0.32 0.42 0.52 0.62 0.72 0.82 0.92 0.03 0.13 0.23 0.33 0.43 0.53 0.63 0.73 0.83 0.93 0.04 0.14 0.24 0.34 0.44 0.54 0.64 0.74 0.84 0.94 0.05
58965 48255 04635 15025 41505 82094 09574 00264 55844 45534 59224 77014 89893 75783 25673 38563 84553 54543 47533 43623 32713 04803 68992 75192 55382 77572 32862 29062 38352 69642 03042 48332 85722 05122 16512 98902 53402 69891
0.35 0.25 0.35 0.45 0.55 0.65 0.75 0.85 0.95 0.06 0.16 0.26 0.36 0.46 0.56 0.66 0.76 0.86 0.96 0.07 0.17 0.27 0.37 0.47 0.57 0.67 0.77 0.87 0.97 0.08 0.18 0.28 0.38 0.48 0.58 0.68 0.78 0.88
47391 76881 57381 98971 43471 48961 74561 22161 01751 01351 12941 44541 77141 02831 47431 73131 01821 29421 38121 38811 19511 70311 13011 26701 10501 74201 00001 0679 6259 9929 7709 2688 3568 9448 0528 7508 9687 6867
0.98 0.09 0.19 0.29 0.39 0.49 0.59 0.69 0.79 0.89 0.99 0.001 0.101 0.201 0.301 0.401 0.501 0.601 0.701 0.801 0.901 0.011 0.111 0.211 0.311 0.411 0.511 0.611 0.711 0.811 0.911 0.021 0.121 0.221 0.321 0.421
7057 4337 5617 0007 0486 3866 1356 3836 9326 8906 1695 7285 7965 0755 6445 6235 8025 4905 2894 3784 7674 3664 2654 4644 7634 4724 2814 3904 6004 1293 8383 7573 8763 1063 6253 2543