Proto-Aire EZ I/O Manual
P/N
3090249_E
14
Electrical
Field Wiring
Maximum & Minimum Field Wire Size
Field wire size is based on the total load amperes, the largest connectable wire sizes for the
terminals. (Wire size is based on the serial plate minimum circuit ampacity.) Refer to National
Electric Code for correction and adjustment factors.
Sizing Wire and Overcurrent Protectors
Check the legend for Minimum Circuit Ampacity (MCA), Maximum Overcurrent Protective
Devices (MOPD), and total RLAs. Follow NEC guidelines.
Branch Circuit(s) must be built to the unit using information supplied on the unit data plate
for Minimum Current Ampacities (MCA) and Maximum Over Current Protective Device(s)
(MOPD).
Proto-Aire EZ components are wired as completely as possible at the factory with all work
completed in accordance with the National Electrical Code. All deviations required by governing
electrical codes will be the responsibility of the installer.
For 208-230/3/60 Compressor Units with Single Power Feed:
To each Proto-Aire EZ provide:
• One 208-230/3/60 branch circuit (neutral wire also required if low
ambient receiver heater utilized)
• One 120/1/60 dedicated GFI circuit if convenience receptacle is applied.
• One ground wire to earth ground
Oil Cycle
Discharge refrigerant carries droplets of oil from the compressor’s outlet. The Oil Separator
separates the oil from the refrigerant. The oil is stored in the Oil Separator until needed. The oil
returns to the system through the high-pressure line and oil filter.
The oil filter removes impurities from the oil. The high-pressure oil is distributed to the electronic
oil level control, which feeds oil into the compressor through a solenoid valve.
Electronic oil regulators monitor oil levels. The units are powered by a 208V power supply.
When the oil level in the compressor drops below ½ sightglass, the fill light comes on, and the oil
solenoid is energized. If after 90 seconds the oil level does not rise above ½ sightglass, the unit
opens the compressor control circuit. If oil becomes available, the electronic oil level control will
automatically re-set and the compressor will resume operation.
