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LEGEND AND NOTES FOR TABLES 14-17
LEGEND
FLA
— Full Load Amps
LRA
— Locked Rotor Amps
MOCP — Maximum Over Current Protection
NEC
— National Electrical Code
RLA
— Rated Load Amps
NOTES:
1. The MCA and Fuse values are calculated in accordance with the
NEC Article 440.
2. Motor RLA and LRA values are established in accordance with
Underwriters Laboratories (UL) Standard 1995.
3. The 575-v units are UL, Canada-listed only.
4. Unbalanced 3-Phase Supply Voltage. Never operate a motor
where a phase imbalance in supply voltage is greater than 2%.
Use the following formula to determine the percentage of voltage
imbalance.
max voltage deviation from average voltage
% Voltage
= 100 x
Imbalance
Example: Supply voltage is 230-3-60
AB = 224 v
A
B
C
BC = 231 v
AC = 226 v
MOTOR
(224 + 231 + 226)
Average Voltage =
Determine maximum deviation from average voltage.
(AB) 227-224 = 3 v
(BC) 231-227 = 4 v
(AC) 227-226 = 1 v
Maximum deviation is 4 v.
Determine percent of voltage imbalance.
% Voltage Imbalance = 100x
This amount of phase imbalance is satisfactory as it is below the
maximum allowable 2%.
IMPORTANT: If the supply voltage phase imbalance is more than 2%,
contact your local electric utility company immediately.
Step 8 — Wind Baffles for Low Ambient
Control
Units with low ambient control (either as a factory-in-
stalled option or a field-installed accessory) require the
addition of wind baffles to ensure full range low ambient
operation. Material data and dimensions for wind baffles
are included in the Appendix C section, Low Ambient
Control, starting on page 50. Fabricate the wind baffles
and mount per instructions.
PRE-START-UP
IMPORTANT: Before beginning Pre-Start-Up or Start-Up,
review Start-Up Checklist at the back of this book. The
Checklist assures proper start-up of a unit and provides a
record of unit condition, application requirements, system
information, and operation at initial start-up.
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage.
Do not attempt to start the condensing unit, even mo-
mentarily, until the following steps have been completed.
Compressor damage may result.
18
average voltage
681
=
=
227
3
3
4
= 1.78%
227
Specifications subject to change without notice.
System Check
1. The electrical power source must agree with the
unit's nameplate rating.
2. Check all air handler(s) and other equipment auxil-
iary components. Consult the manufacturer's instruc-
tions regarding any other equipment connected to
the condensing unit. If the unit has field-installed
accessories, be sure all are properly installed and
correctly wired. If used, the airflow switch must be
properly installed.
3. Check tightness of all electrical connections.
4. Be sure liquid line and low side of the system are
properly leak checked and dehydrated.
5. Be sure the unit is properly charged. See "Prelimi-
nary Charge", below.
6. Open the liquid line and suction line service valves.
7. The crankcase heater must be firmly attached to the
compressor crankcase. Be sure the crankcase is
warm (heater must be on for 24 hours before starting
compressor).
Turn On Crankcase Heater
Turn on the crankcase heater for 24 hours before starting
the unit to be sure all the refrigerant is out of the oil. To ener-
gize the crankcase heater, proceed as follows:
1. Set the space thermostat set point above the space
temperature so there is no demand for cooling.
2. Close the field disconnect.
Preliminary Charge
Before starting the unit, charge liquid refrigerant into the
high side of the system through the liquid service valve. The
amount of refrigerant added must be at least 80% of the op-
erating charge listed in the Physical Data table (Tables 5
and 6). Allow high and low side pressures to equalize be-
fore starting compressor. If pressure do not equalize readily,
charge vapor on low side of system to assure charge in the
evaporator. Refer to GTAC II, Module 5, Charging, Recover,
Recycling, and Reclamation for liquid charging procedures.
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage.
Prior to starting compressor, a preliminary charge of
refrigerant must be added to avoid possible compressor
damage.
START-UP
The compressor crankcase heater must be on for 24 hours
before start-up. After the heater has been on for 24 hours,
the unit can be started. If no time elapsed since the prelimi-
nary charge step was completed, it is unnecessary to wait
the 24-hour period.
Preliminary Checks
1. Check that electric power supply agrees with unit
nameplate data.
2. Verify that the compressor crankcase heater is
securely in place.
3. Check that the compressor crankcase heater has
been on at least 24 hours.
4. Recheck for leaks using the procedure outlined in the
Pre-Start-Up section, Leak Test and Dehydration. If
any leaks are detected, repair as required. Evacuate
and dehydrate as described in the Leak Test and
Dehydration section.
CAS-072-153-01SI Rev. A
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