Carrier 38AUM Series, Installation, Operation & Maintenance Manual, Page: 15 / 44

Example:
38AUMD16
60-ft (18.3 m) linear line length
Equivalent line length 90-ft (27.4 m)
Liquid Lift: 20-ft (6.1 m)
Select line sizes from Table Piping Recommendation (38AUMD):
Liquid 1/2 in
Suction 1-1/8 in.
Charge
Circuit 1: 24.5 lbs (at 75-ft linear length)
Circuit 2: 22.9 lbs
Initial charge = 60% of Operating Charge:
Circuit 1: 0.60 x 21.0 = 14.7 lbs
Circuit 2: 0.60 x 19.3.0 = 13.7 lbs
Field-Charge
Circuit 1: 24.5 – 14.7 = 9.8 lbs
Circuit 2: 22.9 – 13.7 = 9.2 lbs
For linear line lengths longer than 125 ft (38 m), contact your local Carrier representative for system charge value.
Step 7 — Install Accessories
Accessories requiring modifications to unit wiring should be completed now. These accessories may include Winter
Start controls and Low Ambient controls. Refer to the instructions shipped with the accessory.
Step 8 — Complete Electrical Connections
Note: Check all factory and field electrical connections for tightness. Field-supplied wiring shall conform with the
limitations of 63°F (33°C) rise.
All Units — All field wiring must comply with NEC and all local codes. Size wire based on MCA (Minimum Circuit
Amps) on the unit informative plate. See Fig: Power Wiring Connections for power wiring connections to the unit
contactor and terminal block and equipment ground. Provide a ground-fault and short-circuit over-current protection
device (fuse or breaker) per NEC Article 440 (or local codes). Refer to unit informative data plate for MOCP (Maximum
Over-current Protection) device size. Refer to unit label diagram for line-side information. Affix the crankcase heater
warning sticker to the unit
disconnect switch.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could cause 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), and local electrical codes.
WARNING
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could cause in personal injury or death.
Using unit-mounted convenience outlets: Units with unit-mounded convenience outlet circuits will often require that
two disconnects be opened to de-energize all power to the unit. Treat all units as electrically energized until the
convenience outlet power is also checked and de-energization is confirmed. Observe National Electrical Code Article
210, Branch Circuits.
WARNING
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