22
P5417050-rev.1
8. Electrical Wiring
8.1 General Check
1. Make sure that the field-selected electrical components: (main power switches, circuit breakers,
wires, conduit connectors, and wire terminals) are properly labeled in accordance with electrical data
as specified in the Engineering Manual. Make sure that the components comply with the National
Electrical Code (NEC).
2. Confirm that the power supply voltage is within ±10% of the rated voltage.
3. Verify the capacity of the electrical wires.
If the power supply capacity is too low, the system cannot be started due to a voltage drop.
4. Verify that the ground wiring is securely connected.
●
All electrical work must be done as outlined in this manual and in accordance with this manual.
Substandard work can result in fire and damage to the unit.
●
Use specified cables between units and choose the cables correctly. If not, an electrical shock or
fire may occur.
●
Do not open the service cover or access panel for the indoor or outdoor units without turning OFF
the main power supply. It can result in an electrical shock.
●
Turn OFF the main power switch of the indoor unit and the outdoor unit before attempting any electrical
wiring work or a periodical check is performed. Not doing so will result in an electric shock or a fire.
●
Check to ensure that the indoor fan and the outdoor fan have stopped before attempting any
electrical wiring work or for any scheduled electrical work that is being performed.
●
Tighten screws according to the following torque.
M3.5: 0.9 ft·lbs (1.2 N·m)
M4: 0.7 to 1.0 ft·lbs (1.0 to 1.3 N·m)
●
Secure all cables together with zip-ties and seal the connecting hole against moisture and insects.
●
Run the electrical wiring through the connecting hole in the side cover when using conduit.
●
Secure the wired controller cable using the cable band inside the electrical box.
8.2 Electrical Wiring Capacity
8.2.1 Field Minimum Wire Sizes for Power Supply
•
This equipment can be installed with a Ground Fault Circuit Breaker (GFCI), which is a recognized
measure for added protection to a properly grounded unit. Install appropriate sized breakers/fuses/
overcurrent protection switches, and wiring in accordance with local, state and NEC codes and
requirements. The equipment installer is responsible for understanding and abiding by applicable
codes and requirements.
•
Do not operate the system until all check points have been cleared.
▫ Confirm that the electrical resistance is more than one megaohm by measuring the resistance
between ground and the terminal of the electrical parts. If it is less than one megaohm, do not
operate the system until the source of the electrical drain is found and repaired.
▫ Confirm that the stop valves of the outdoor unit are fully opened, and then start the system.
▫ Apply power to the outdoor unit(s) at least 12 hours prior to operation of the system for preheating
of the compressor oil.
•
Do not touch any of the parts by hand at the discharge gas side, since the compressor chamber and
the pipes at the discharge side are heated to temperatures higher than 194
o
F (90
o
C).
