Ins Talla T Ion - E Le C T R I C A L - Conair Thermolator TW-S User Manual

I n sta llatio n - E l e c t ri ca l
All wiring must comply with local codes and the National Electric Code (NEC). Full Load
Amperes (FLA) and other unit electrical data are on the unit nameplate. A unit specific
electrical schematic ships with the unit. Measure each leg of the main power supply volt-
age at the main power source. Voltage must be within the voltage utilization range given
on the drawings included with the unit. If the measured voltage on any leg is not within
the specified range, notify the supplier and correct before operating the unit. Voltage im-
balance must not exceed two percent. Excessive voltage imbalance between the phases of
a three-phase system can cause motors to overheat and eventually fail. Voltage imbalance
is determined using the following calculations:
%Imbalance = (V – V ) x 100 / V
avg x
V = (V1 + V2 + V3) / 3
avg
V = phase with greatest difference from V
x
For example, if the three measured voltages were 442, 460, and 454 volts, the average
would be:
(442 + 460 + 454) / 3 = 452
The percentage of imbalance is then:
(452 – 442) x 100 / 452 = 2.2 %
This exceeds the maximum allowable of 2%.
There is a terminal block for main power connection to the main power source. The main
power source should be connected to the terminal block through an appropriate disconnect
switch. There is a separate lug in the main control panel for grounding the unit. Check the
electrical phase sequence at installation and prior to start-up. Operation of the unit with in-
correct electrical phase sequencing will result in improper pump performance. Check the
phasing with a phase sequence meter prior to applying power. The proper sequence should
read "ABC" on the meter. If the meter reads "CBA", open the main power disconnect and
switch two line leads on the line power terminal blocks (or the unit mounted disconnect).
Do not interchange any load leads that are from the unit contactors or the motor terminals.
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avg
avg
I ns ta l l a t i on I 3-5