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EVACUATION/DEHYDRATION
Evacuate and dehydrate the connected refrigeration sys-
tem(s) (excluding the CHS unit) to 500 microns using a two-
stage vacuum pump attached to the service ports outside the
CHS service valves, following description in GTAC II,
Module 4, System Dehydration.
WARNING
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal
injury, death and/or equipment damage.
R-410A refrigerant systems operate at higher pressures
than standard R-22 systems. Do not use R-22 service
equipment or components on R-410A refrigerant
equipment.
IMPORTANT: Charge in Cooling mode only!
PRELIMINARY CHARGE
Before starting the unit, charge R-410A liquid refrigerant into
the high side of each CHS circuit through the liquid service
valve(s). The amount of refrigerant added must be at least
80% of the operating charge listed in Table 4 for LINEAR
line length LESS the factory charge quantity (if factory ship-
ping charge has not been removed). See the following
example.
Allow high and low side pressures to equalize. If pressures
do not equalize readily, charge R-410A vapor (using special
service manifold with expansion device) into the suction line
service port for the 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.
Example:
CHS243
60 ft (18.3 m) linear line length
Equivalent line length 90 ft (27.4 m)
Cooling Liquid Lift: 20 ft (6.1 m)
Select line sizes from Table 4 (CHS):
Liquid 1/2 in. (provides liquid lift to 24 ft (7.3 m))
Vapor 1-1/8 in.
Charge (each circuit):
1/2 in. liquid line: 30.7 lb (at 75 ft linear length)
80% of Operating Charge:
0.80 x 30.7 = 24.6 lb
Factory Shipping Charge: 9 lb
Field-Charge (each circuit):
24.6 – 9.0 = 15.6 lb
For linear line lengths longer than 125 ft (38.1 m), contact
your local representative for system charge value.
Step 6 — Install Accessories
Accessories requiring modifications to unit wiring should be
completed now. These accessories may include Winter
Start controls, Low Ambient controls, phase monitor, Com-
pressor Lockout. Refer to the instructions shipped with the
accessory. Additionally, for low ambient controls, refer to
Table 8.
12
CHS183
CHS243
NOTE(S):
a
Applies to Cooling mode of operation only.
b
Wind baffles (field-supplied and field-installed) are recommended for all units
with low ambient head pressure control. Refer to Low Ambient Control Instal-
lation Instructions (shipped with accessory) for details.
Step 7 — Complete Electrical Connections
Failure to follow this warning could result in personal
injury or death.
Do not use gas piping as an electrical ground.
Unit cabinet must have an uninterrupted, unbroken
electrical ground to minimize the possibility of personal
injury if an electrical fault should occur. This ground may
consist of electrical wire connected to unit ground lug in
control compartment, or conduit approved for electrical
ground when installed in accordance with NEC (National
Electrical Code); ANSI/NFPA 70, latest edition (in
Canada, Canadian Electrical Code CSA [Canadian
Standards Association] C22.1), and local electrical
codes.
NOTE: Check all factory and field electrical connections for
tightness. Field-supplied wiring shall conform with the limita-
tions of 63°F (33°C) rise.
FIELD POWER SUPPLY
If equipped with optional Powered Convenience Outlet:
The power source leads to the convenience outlet's
transformer primary are not factory connected. Installer
must connect these leads according to required opera-
tion of the convenience outlet. If an always-energized
convenience outlet operation is desired, connect the
source leads to the line side of the unit-mounted discon-
nect. (Check with local codes to ensure this method is
acceptable in your area.) If a de-energize via unit discon-
nect switch operation of the convenience outlet is de-
sired, connect the source leads to the load side of the
unit disconnect. On a unit without a unit-mounted discon-
nect, connect the source leads to compressor contactor
C with unit field power leads.
All units except 208/230-v units are factory wired for the
voltage shown on the nameplate. If the 208/230-v unit is to
be connected to a 208-v power supply, the control trans-
former must be rewired by moving the black wire with the
1/4 in. female spade connector from the 230-v connection
and moving it to the 208-v 1/4 in. male terminal on the pri-
mary side of the transformer. Refer to unit label diagram for
additional information.
Field power wires are connected to the unit at line-side
pressure lugs on compressor contactor C and TB1 (see wir-
ing diagram label for control box component arrangement)
or at factory-installed option non-fused disconnect switch.
Max wire size is no.4 AWG (copper only).
NOTE: TEST LEADS - Unit may be equipped with short
leads (pigtails) on the field line connection points on contac-
tor C or optional disconnect switch. These leads are for fac-
tory run-test purposes only; remove and discard before
Specifications subject to change without notice.
Table 8 — Minimum Outdoor Air Operating
Temperature
PERCENT
UNIT
COMPRESSOR
CAPACITY
100
100
WARNING
MINIMUM OUTDOOR TEMP
°F (°C)
a
Head Pressure
Standard Unit
Control
b
35 (1.7)
–20 (–28.9)
35 (1.7)
–20 (–28.9)
CHS-180-240-01SI Rev. A
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