electrical
Installation requirements
Supply Power Wiring
It is the installer’s responsibility to provide power supply wiring to the unit terminal block or the
1.Verify the power supply available is compatible with the unit nameplate ratings. The supply power must be within 10%of the rated voltage listed on the unit nameplate.
2.Reference the electrical data in Table I-
3.If using a
4.Complete the unit power wiring connections onto either the main terminal block or the
WARNING
Ground Wire!
All
WARNING
Grounding Required!
Follow proper local and state elec- trical code on requirements for grounding. Failure to follow code could result in death or serious in- jury.
5.Provide proper unit grounding in accordance with local and national codes.
Electrical Data Calculations
RLA = rated load amps
Compressor LRA = locked rotor amps Fan motor LRA = locked rotor amps, N.E.C. Table 430 - 151
FLA = Full load amps, N.E.C. Table 430 - 150
Voltage utilization range is ±10% Minimum circuit ampacity (MCA)
=1.25 x largest motor amps (FLA or RLA) + the sum of the remaining motor amps.
Maximum fuse size (MFS) and maximum circuit breaker size (MCB) = 2.25 x largest motor amps (FLA or RLA) + the sum of the remaining motor amps.
Note: If the rating value determined does not equal a standard current rating of over current protective device, use the next lower standard rating for the marked maximum rating.
Voltage Range
Voltages must be within +- 10% the nameplate voltage. Ensure the unit voltage is balanced by measuring at the compressor terminals. Voltage imbalance on three phase systems can cause motor overheating and premature failure. Maximum allowable imbalance is 2.0%.
Voltage Imbalance
Read the voltage at the compressor terminals to determine if it is balanced. Voltage imbalance on three phase systems can cause motor overheating and premature failure. The maximum allowable imbalance is 2.0%. Voltage imbalance is defined as 100 times the sum of the deviation of the three voltages from the average (without regard to sign) divided by the average voltage. For example, if the three measured voltages are 221, 230, and 227, the average voltage would be:
(221 + 230 + 227) = 226 volts
3
The percentage of voltage imbalance is then:
100 *
226
In this example, 2.2% imbalance is not acceptable. Whenever a voltage imbalance of more than 2.0% exists, check the voltage at the unit disconnect switch. If the imbalance at the unit disconnect switch does not exceed 2.0%, faulty unit wiring is causing the imbalance. Conduct a thorough inspection of the unit electrical wiring connections to locate the fault, and make any repairs necessary.
WARNING
Live Electrical Components!
During installation, testing, servicing, and troubleshooting this equipment, it may be necessary to work with live electrical components. Have a qualified licensed electrician or other individual who is properly trained in handling live electrical components perform these tasks. Failure to follow all electrical safety precautions when exposed to live electrical components could result in death or serious injury.
WARNING
Hazardous Voltage!
Disconnect all electric power, including remote disconnects before servicing. Follow proper lockout/ tagout procedures to ensure power cannot be inadvertently energized. Failure to disconnect power before servicing could result in death or serious injury.
CAUTION
Use Copper Conductors Only! Unit terminals are not designed to accept other type conductors. Failure to use copper conductors may result in equipment damage.
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