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PKG-SVX027A-EN
Installation - Electrical
Unit Wiring Diagrams
Specific unit wiring diagrams are provided on the inside of
the control panel door. Use these diagrams for
connections or trouble analysis.
Supply Power Wiring
It is the responsibility of the installer to provide power
supply wiring to the unit terminal block or the non-fused
disconnect switch option. Wiring should conform to NEC
and all applicable code requirements.
Bring supply wiring through the knockout in the lower left
side of the unit control panel. Connect the three phase
wires to the power terminal block or the non-fused
disconnect switch in the control box terminals.Refer to
specific wiring diagrams and fuse information in the
control panel.
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) / 3 = 226 volts
The percentage of voltage imbalance is then:
100 * (226 — 221) / 226 = 2.2%
Phase Monitor
Unit is equipped with phase monitor in control box. The
phase monitor will protect against phase loss, imbalance
and reversal of line voltage. If a fault occurs, the red LED
will energize. While the fault condition is present, the
phase monitor interrupts the 115V control circuit. If no
faults are observed, a green LED will be energized.
Control Power
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.
Access the connection terminal block through the control
panel on the upper left side of the unit. All wiring should
conform to NEC and applicable local code requirements.
Be sure all wiring connections are secure. Reference the
unit specific diagrams inside the control panel.
WARNING
Hazardous Service Procedures!
Failure to follow all precautions in this manual and on the
tags, stickers, and labels could result in death or serious
injury.
Technicians, in order to protect themselves from
potential electrical, mechanical, and chemical hazards,
MUST follow precautions in this manual and on the tags,
stickers, and labels, as well as the following instructions:
Unless specified otherwise, disconnect all electrical
power including remote disconnect and discharge all
energy storing devices such as capacitors before
servicing. Follow proper lockout/tagout procedures to
ensure the power can not be inadvertently
energized.When necessary to work with live electrical
components, have a qualified licensed electrician or
other individual who has been trained in handling live
electrical components perform these tasks.
NOTICE
Use Copper Conductors Only!
Failure to use copper conductors could result in
equipment damage as the equipment was not
designed or qualified to accept other types of
conductors.
NOTICE
Motor Damage!
Correct phase sequence is critical. If phase sequence of
the incoming line voltage is not correct, it could result
in motor damage.
NOTICE
Component Damage!
Failure to follow instructions below could result in
immediate or premature component failures. Unit
transformers are sized to provide power to the unit
only. Do not use these transformers to supply power to
field equipment.
