Yaskawa VCD 723 - Manual (Page 31)

2 Installation and Start-up
25 Pre-Power Check
9/15/93
The VCD 723 must be solidly grounded using the main circuit ground terminal
G (E).
●
Ground wire resistance should be 100 ohms or less.
●
NEVER ground the VCD 723 in common with welding machines, motors,
or other large current electrical equipment. Run the ground lead in a separate
conduit from leads for large current electrical equipment.
●
Use ground lead size listed in table 6, and make the length as short as
possible.
● Where several VCD 723 drives are used side by side, all should be grounded
directly, or daisy chained to earth ground (see Figure 5). DO NOT FORM A
LOOP WITH THE GROUND LEADS.
Grounding
CORRECT CORRECT NOT
ACCEPTABLE
GROUND
POLE
GROUND
POLE
GROUND
POLE
LA-10
Figure 5. Proper Grounding of Three VCD 723 Drives
❏ Make sure wires are properly connected.
❏ Verify ground connections to the drive.
❏ Disconnect motor from its load. To ensure safety, prior to test operation,
disconnect the coupling or belt which connects the motor with the machine
so that motor operation is isolated. If an operation must be performed while
the motor is directly connected to the machine, use great care to avoid any
possible hazardous condition.
❏ For 460V, 15HP and above verify that the power voltage select connector in
the VCD 723 is positioned correctly for the input power line voltage (see
Figure 6). Voltage is preset to 460V at the factory. Reposition if required.
❏ Check that all mechanical connections inside VCD 723 are tight.
Pre-Power
Check
CAUTION
To prevent damage to the drive, the following checks must be
performed before applying input power.