Grounding – Yaskawa P7B Drive Bypass User Manual
Page 43
Electrical Installation 2 - 5
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Grounding
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Drive and Motor Ground Wire Landing
The Drive ground lug (terminal
) is connected to the enclosure. The enclosure ground lug must be connected to earth
ground. See Figures 2.1 and 2.2.
The Drive has a second ground lug to accept the motor ground lead. See Figure 2.9.
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Ground Wiring Precautions
Observe the following precautions when connecting the ground wire:
1.
208-240 VAC Drives should have a ground connection with resistance of less than 100
Ω
..
2.
480 VAC Drives should have a ground connection with resistance of less than 10
Ω
..
3.
Do not share the ground wire with other devices, such as large-current electrical equipment.
4.
Always use a ground wire that complies with technical standards on electrical equipment and minimize the length of the
ground wire. Leakage current flows through the Drive. Therefore, if the distance between the ground rod and the ground
terminal is too long, potential on the ground terminal of the Drive will become unstable.
5.
When using more than one Drive, be careful not to loop the ground wire.
Fig 2.4 Ground Wiring Examples
For grounding connection to earth ground see Figures 2.1 and 2.2.
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Control Circuit Ground Terminals
The removable Drive control terminal card provides two ground terminals (marked TB3 and TB4) to accept the control wire
shield connection. The control wire shield should be connected on this end only, the opposite end should be isolated with
electrical tape.
IMPORTANT
Grounding of the Bypass enclosure and motor is required for proper system operation.
NO
OK
OK
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