ELECTRICAL WIRING
53
ENGLISH
CAUTION
!
• Use the 2-core shield cables for communication cables. Never use them together with power
cables.
• The conductive shielding layer of cable should be grounded to the metal part of both units.
• Never use multi-core cable.
• As this unit is equipped with an inverter, to install a phase leading capacitor not only will
deteriorate power factor improvement effect, but also may cause capacitor abnormal heating.
Therefore, never install a phase leading capacitor.
• Make sure that the power unbalance ratio is not greater than 2 %. If it is greater the units
lifespan will be reduced.
CAUTION
!
When the 400 volt power supply is applied to “N” phase by mistake, check damaged parts in
control box and replace them.
Precautions when laying power wiring
Use round pressure terminals for connections to the power terminal block.
Round pressure terminal
Power cable
When none are available, follow the instructions below.
- Do not connect wiring of different thicknesses to the power terminal block. (Slack in the power
wiring may cause abnormal heat.)
- When connecting cable which is the same thickness, do as shown in the figure below.
- For wiring, use the designated power cable and connect firmly, then secure to prevent outside
pressure being exerted on the terminal block.
- Use an appropriate screwdriver for tightening the terminal screws. A screwdriver with a small
head will strip the head and make proper tightening impossible.
- Over-tightening the terminal screws may break them.
