27
T_C-IOM-2A
Installation
Table 4
Temperature vs Resistance
Nominal Resistance
Degrees F° Degrees C°
-20°
-28.9°
170.1 K - Ohms
-15°
-26.1°
143.5 K - Ohms
-10°
-23.3°
121.4 K - Ohms
-5°
-20.6°
103.0 K - Ohms
0°
-17.8°
87.56 K - Ohms
5°
-15.0°
74.65 K - Ohms
10°
-12.2°
63.80 K - Ohms
15°
-9.4°
54.66 K - Ohms
20°
-6.7°
46.94 K - Ohms
25°
-3.8°
40.40 K - Ohms
30°
-1.1°
34.85 K - Ohms
35°
1.7°
30.18 K - Ohms
40°
4.4°
26.22 K - Ohms
45°
7.2°
22.85 K - Ohms
50°
10.0°
19.96 K - Ohms
55°
12.8°
17.47 K - Ohms
60°
15.6°
15.33 K - Ohms
65°
18.3°
13.49 K - Ohms
70°
21.1°
11.89 K - Ohms
75°
23.9°
10.50 K - Ohms
80°
26.7°
9.297 K - Ohms
85°
29.4°
8.247 K - Ohms
90°
32.2°
7.330 K - Ohms
95°
35.0°
6.528 K - Ohms
100°
37.8°
5.824 K - Ohms
Temperature
Use the checklist provided below in conjunction with the “Gen-
eral Unit Requirements” checklist to ensure that the unit is prop-
erly installed and ready for operation.
HAZARDOUS VOLTAGE!
DISCONNECT ALL ELECTRIC POWER INCLUDING REMOTE
DISCONNECTS BEFORE SERVICING.
Failure to disconnect power before servicing can cause
severe personal injury or death.
[ ] Check all electrical connections for tightness and “point of ter-
mination” accuracy.
[ ] Verify that the condenser airflow will be unobstructed.
[ ] Verify that the condenser fan and indoor blower turn freely
without rubbing and are properly tightened on the shafts.
[ ] Check the supply fan belts for proper tension and the fan
bearings for sufficient lubrication. If the belts require adjust-
ment, or if the bearings need lubricating, refer to the mainte-
nance section of this manual for instructions.
[ ] Verify that a condensate trap is installed and the piping is
properly sized and pitched.
[ ] Verify that the correct size and number of filters are in place.
[ ] Inspect the interior of the unit for tools and debris and install all
panels in preparation for starting the unit.
Voltage Imbalance
Three phase electrical power to the unit must meet stringent re-
quirements for the unit to operate properly. Measure each leg
(phase-to-phase) of the power supply. Each reading must fall
within the utilization range stamped on the unit nameplate. If any
of the readings do not fall within the proper tolerances, notify the
power company to correct this situation before operating the
unit.
Excessive three phase voltage imbalance between phases
will cause motors to overheat and eventually fail. The maximum
allowable voltage imbalance is 2%. Measure and record the
voltage between phases 1, 2, and 3 and calculate the amount
of imbalance as follows:
% Voltage Imbalance =
100 X
AV - VD
where;
AV
AV (Average Voltage) =
Volt 1 + Volt 2 + Volt 3
3
V1, V2, V3 = Line Voltage Readings
VD = Line Voltage reading that deviates the farthest from
the average voltage.
Example: If the voltage readings of the supply power
measured 403, 402, and 389, the average volts would be:
403 + 402 + 389 = 398 Avg.
3
VD (reading farthest from average) = 389
The percentage of Imbalance equals:
100 X 398 - 389 = 2.2%
398
The 2.2% imbalance in this example exceeds the maximum al-
lowable imbalance of 2.0%. This much imbalance between
phases can equal as much as a 20% current imbalance with a
resulting increase in motor winding temperatures that will de-
crease motor life. If the voltage imbalance is over 2%, notify the
proper agencies to correct the voltage problem before operat-
ing this equipment.
Summary of Contents for Precedent TSC060
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