Start-Up; General; Crankcase Heaters; Confirm The Input Power Phase Sequence - Carrier Omnizone 50BVC Installation, Start-Up, Service And Controls Operation And Troubleshooting

Table 15 — Thermistor Resistance vs Temperature Values for Supply-Air and Return Air Temperature Sensor
TEMP TEMP
(C) (F)
-39 -39.44
-37 -38.33
-35 -37.22
-33 -36.11
-31 -35.00
-29 -33.89
-27 -32.78
-25 -31.67
-23 -30.56
-21 -29.44
-19 -28.33
-17 -27.22
-15 -26.11
-13 -25.00
-11 -23.89
-9 -22.78
-7 -21.67
-5 -20.56
-3 -19.44
-1 -18.33
1 -17.22
3 -16.11
5 -15.00
7 -13.89
9 -12.78
11 -11.67
13 -10.56
15 -9.44
17 -8.33
19 -7.22
21 -6.11
23 -5.00
25 -3.89
27 -2.78
29 -1.67
31 -0.56
33 0.56
35 1.67

START-UP

Complete the Start-Up Checklist on page CL-1
General —
before attempting system start-up.
CRANKCASE HEATERS — The 50BVT,V,W,34-064
units include crankcase heaters. Crankcase heaters are ener-
gized as long as there is power to the unit.
Wait 24 hours before starting the compressors to permit
warming by the crankcase heaters.
AFTER 24 hours, continue with the procedures below.
CONFIRM THE INPUT POWER PHASE SEQUENCE —
The input power phase rotation sequence must be L1-L2-L3 =
ABC (or forward or clockwise) as indicated with a phase
rotation meter. Incorrect input phase rotation will cause the com-
pressors to rotate in reverse, which results in no cooling capacity.
IMPORTANT: On VAV units, fan rotation direction
CANNOT be used for the phase sequence check; fan
rotation for VAV units with a variable speed drive is
independent of the unit input wiring sequence.
RESISTANCE TEMP
(OHMS) (C)
323,839 37
300,974 39
279,880 41
260,410 43
242,427 45
225,809 47
210,443 49
196,227 51
183,068 53
170,775 55
159,488 57
149,024 59
139,316 61
130,306 63
121,939 65
114,165 67
106,939 69
100,218 71
93,909 73
88,090 75
82,670 77
77,620 79
72,911 81
68,518 83
64,419 85
60,592 87
57,017 89
53,647 91
50,526 93
47,606 95
44,874 97
42,317 99
39,921 101
37,676 103
35,573 105
33,599 107
31,732 109
29,996 111
(10,000 ohms)
TEMP RESISTANCE
(F) (OHMS)
2.78 28,365
3.89 26,834
5.00 25,395
6.11 24,042
7.22 22,770
8.33 21,573
9.44 20,446
10.56 19,376
11.67 18,378
12.78 17,437
13.89 16,550
15.00 15,714
16.11 14,925
17.22 14,180
18.33 13,478
19.44 12,814
20.56 12,182
21.67 11,590
22.78 11,030
23.89 10,501
25.00 10,000
26.11 9,526
27.22 9,078
28.33 8,653
29.44 8,251
30.56 7,866
31.67 7,505
32.78 7,163
33.89 6,838
35.00 6,530
36.11 6,238
37.22 5,960
38.33 5,697
39.44 5,447
40.56 5,207
41.67 4,981
42.78 4,766
43.89 4,561
If the compressor is rotating in the wrong direction, it may:
emit increased noise; shut down due to internal overload
protection; have only a small decrease in suction pressure when
it starts; or have only a small increase in discharge pressure
when it starts. Also, no cooling will be produced at the
evaporator. If any of these conditions occurs, refer to the
Service section to correct the compressor rotation before
continuing.
INTERNAL WIRING — Check all electrical connections in
unit control boxes; tighten as required.
RETURN-AIR FILTERS — Check that correct filters are
installed in filter tracks (see Tables 2 and 3). Do not operate
unit without return-air filters.
COMPRESSOR MOUNTING — Compressors are internal-
ly mounted on resilient rubber supports. Do not loosen or re-
move compressor holddown bolts.
REFRIGERANT SERVICE PORTS — Each refrigerant sys-
tem has a total of 2 Schrader-type service gage ports per circuit.
One port is located on the suction line, and one on the compres-
sor discharge line. Be sure that caps on the ports are tight.
24
TEMP TEMP RESISTANCE
(C) (F) (OHMS)
113 45.00
115 46.11
117 47.22
119 48.33
121 49.44
123 50.56
125 51.67
127 52.78
129 53.89
131 55.00
133 56.11
135 57.22
137 58.33
139 59.44
141 60.56
143 61.67
145 62.78
147 63.89
149 65.00
151 66.11
153 67.22
155 68.33
157 69.44
159 70.56
161 71.67
163 72.78
165 73.89
167 75.00
169 76.11
171 77.22
173 78.33
175 79.44
177 80.56
179 81.67
181 82.78
183 83.89
185 85.00
187 86.11
4,367
4,182
4,006
3,838
3,679
3,525
3,380
3,242
3,111
2,985
2,865
2,751
2,642
2,538
2,438
2,343
2,252
2,165
2,082
2,003
1,927
1,855
1,785
1,718
1,655
1,594
1,536
1,480
1,427
1,375
1,326
1,279
1,234
1,190
1,149
1,109
1,070
1,034