Proper voltage balance, Voltage/phase monitor – ClimaCool UCR 30, 50 and 70 tons Manual User Manual
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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 that 2% occurs. This causes motors to run at high 
temperatures and may aff ect 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
Next, 100(228-226) = 0.9%
 228
The voltage imbalance of the three phase circuit is 0.9%. This 
is well under the 2% range. 
 
Voltage/Phase Monitor
Voltage/phase monitors are factory supplied for fi eld 
installation with the CoolLogic Master Control Panel. The 
voltage/phase monitor helps guard the chiller bank against 
voltage fl uctuations, phase failure or phase reversal 
conditions. The voltage/phase monitor has three wires 
that connect to the main three phase power chiller bank 
input. Two low voltage control wires are connected to the 
CoolLogic Master Control Panel and must be run together 
with the power wiring. Do not install control wiring in the 
same conduit as line voltage wiring or with wires that switch 
highly inductive loads such as contactor and relay coils. 
WARNING!
WARNING! To avoid possible injury or death due to electrical 
shock, open the power supply disconnect switch and secure it 
in an open position during installation.
CAUTION!
CAUTION! Use only copper conductors for field installed 
electrical wiring. Unit terminals are not designed to accept 
other types of conductors.
SAFETY WARNING
High voltage is used to operate this equipment. Failure to observe standard electrical safety procedures may result 
in serious injury. Only persons qualified and / or properly trained should attempt to install, operate and maintain this 
equipment. These chillers come fully charged with refrigerant. Installation, and start – up should be accomplished by 
technicians who are fully certified to handle refrigerants, as required by 40 CRF Part 82, subpart F of the Recycling 
and Emissions Reduction Act. Scroll compressors are used in this equipment. Phase verification is required for proper 
rotation direction. Incorrect rotation will result in elevated sound and internal overload trip failure.