Art. 430.74 (A)

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rmonroe

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We have 3-phase 480-volt 1hp fan motors through out the plant. All of these motors have magnetic starters on them. None of this motors have disconnect means except back to the breaker panel. Some of these fans are in close proximity to the panels, which supply the branch circuits.

Article 430.74 (A) ? Motor control circuits shall be arranged so that they will be disconnected from all sources?

Does this mean disconnects should be install before the magnetic starter?

Thanks

rmonroe
 
Re: Art. 430.74 (A)

Every motor requires a disconnect
Every motor controller requires a disconnect.
These disconnects must be with in sight. There are some exceptions, please refer to the following rules in 430.102 and there is a major change in the 2002 cycle from the 1999 version.
I think your question is more concerned with the above than the control circuit disconnect
 
Re: Art. 430.74 (A)

Tom

Some of these fans are mounted about floor level about 12’ to 15’. The disconnect is mounted close to the fans and the motor starters are accessible at floor level just below the fan. Would this comply with Art.430.74 (A)?

Thanks for the information.
 
Re: Art. 430.74 (A)

What is the source for the control ciruit voltage?
The disconnect for the control circuit has to be adjacent to the controller, but there are some execptions in the 2002 NEC. Does your installation qualify for the exceptions?
 
Re: Art. 430.74 (A)

The coil voltage for the magnetic starter is 480 Volts. This is your basic three wire control system using your main supply voltage for control.
 
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