Example of earthing (grounding)
Make the separate earth (ground) connection for the converter, inverter, and reactor wherever possible.
The earthing (grounding) cable should be as close as possible to the power cables, and all these cables should be in
The converter and the dedicated reactor are allowed to have the common (single-point) earth (ground) system (unless the
reactor is earthed (grounded) by being mounted on a panel of the enclosure).
If the inverter and the converter are installed far apart and the main circuit cables between them (P to P and N to N) are too
long to store in an enclosure, the inverter earthing (grounding) cable is allowed to be connected to the converter and run
as close as possible to the main circuit cables in parallel.
When the main circuit cables are short enough to store in an enclosure, the inverter is allowed to join in the common
(single-point) earth (ground) connection (c).
The motor earthing (grounding) cable is allowed be connected to the inverter earth (ground) terminal.
Connection of the converter and the
Connection in common bus regeneration mode
When the multifunction regeneration converter is used in common bus regeneration mode, multiple inverters can be
connected to the converter. (The allowable number or permissible total capacity of inverters to be connected differs according
to the converter capacity and the harmonic suppression function condition. Refer to
the total capacity of the connected inverters must not exceed the applicable inverter capacity.
• For the multiple inverter connection, place the higher capacity inverter in the lower number axis.
• Junction terminals and cross wiring may be required for the wiring of the multiple inverters. For the gauge of cable used
between the two junction terminals, refer to the descriptions in the following figure. Total capacity of higher-number axis
inverters must be considered for the cable selection.
• It is recommended to install a fuse on each inverter power cable used between the inverter and the junction terminal, as
shown in the following figure. Select a fuse according to the motor capacity. (Refer to
When using a motor whose capacity is smaller than the inverter capacity by two ranks or more, select the fuse with the
capacity that is one rank lower than the inverter capacity.
• Keep the wiring length (total length of cables) of each main circuit terminal (P/+ or N/-) between the converter and each
inverter within 5 m or less when converter's harmonic suppression function is disabled or within 50 m or less when the
function is enabled.
• The total wiring length between terminals P/+ or terminals N/- on the converter and connected inverters should not exceed
the length shown in the following table.
Harmonic suppression enabled
Connection of the converter and the multiple inverters
Harmonic suppression disabled
INSTALLATION AND WIRING
: Earthing (grounding) cable
156.) Select the converter so that