ClimaCool IOM AR2 SERIES - Manual (Page 11)

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ELECTRICAL CONNECTION
The compliance of the installation to relevant electrical codes
is the responsibility of the installer . Before carrying out any
electrical work, confirm that the main power supply is isolated .
The installer must ensure that the correct electrical drawing is
available .
Module Power Wiring
The power for each module should be taken from a customer
supplied, fused main power supply panel . It is further
recommended that the incoming power be supplied from a
properly sized disconnect switch . It is the responsibility of the
installer to provide adequate fusing or circuit breaker protection
for the incoming power to each module . Proper grounding of the
module is mandatory . A typical power wiring schematic is located
on page 63 - Power Distribution .
Module Control Wiring
After the power wiring has been run, the control wires can then
be connected . The wires should be carefully marked and installed
onto the terminals shown on the wiring diagram . External control
wires should be connected to the relevant terminals and devices .
All control wiring and external wiring to the sensors should not
be run in the same conduit as the power wiring .
Control Wiring Sizes and Lengths
When running control wires, proper gauged wires should be
used . The control wiring for the compressor contactors must be
in accordance with the minimum wire gage shown on the wiring
diagram . With 14 AWG the maximum distance allowed is 250
feet . With 16 AWG, 100 feet is acceptable . You should not exceed
50 feet when using 18 AWG . These lengths and gages are for the
use of 24 volt control circuits .
Electrical Phase Sequencing
Proper clockwise rotation for scroll compressor motors
is important to prevent damaging the compressors . If you
have access to a phase sequence indicating instrument it is
recommended to use this following the manufactures directions .
If not, you may “bump test” the compressors one at a time
with pressure gauges attached to the high and low gauge ports
of the compressors to check for proper rotation . Energize the
compressor for a few seconds to ensure the discharge pressure
gauge increases significantly . If the discharge pressure docs not
increase, proper rotation is reversed . You can quickly reverse
compressor rotation by opening the main electrical disconnect
and switching any two of the main power supply leads feeding
that compressor’s contactor .
Proper Voltage Balance
Occasionally, in three phase circuits, a voltage imbalance occurs
between phases . It is not recommended to operate equipment
when an imbalance greater than 2% occurs . This causes motors
to run at high temperatures and may affect their longevity . The
following example describes how to calculate the average voltage
of the three phases to see if the imbalance is greater than 2% .
Example: Line one = 226V; Line two = 230V; Line three = 228V
The average is: 226+230+228 = 228V
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Next, 100 x (228-226) = 0 .9%
228
The voltage imbalance of the three phase circuit is 0 .9% . This is
well under the 2% range .
Checking
Before power is applied to the system, the wiring should he
visually inspected for loose connections or frayed terminal
connections . All control wiring should follow wiring instructions
supplied in the project submittal package .
Electrical Connection