Motor Starter
Motor Starter
(OP)
Hi forum members,
A conventional motor starter usuallly consists of a motor circuit breaker, a contactor and an overload device which is quite often combined in the motor breaker.The above three components are mounted in the same enclosure but I'm confronted with a problem because the motor breaker supplied is not provided with facilty to externally isolate the power source for maintenance purposes. The enclosure door has to be opened to physically isolate the circuit breaker before any repairs or maintenance is effected on this source.I am looking for the possibility to install a disconnector or isolator, with lockout and tag out facilities, to physically isolate the power source before any intervention is effected on this starter.This isolator is available at hand and my intention is to install it just before the circuit breaker.
I have seen many designs with a disconnector switch , used for isolation purposes, installed just before circuit breakers or switch fuses? Am I in the right direction?
Thanks.
Guardiano
A conventional motor starter usuallly consists of a motor circuit breaker, a contactor and an overload device which is quite often combined in the motor breaker.The above three components are mounted in the same enclosure but I'm confronted with a problem because the motor breaker supplied is not provided with facilty to externally isolate the power source for maintenance purposes. The enclosure door has to be opened to physically isolate the circuit breaker before any repairs or maintenance is effected on this source.I am looking for the possibility to install a disconnector or isolator, with lockout and tag out facilities, to physically isolate the power source before any intervention is effected on this starter.This isolator is available at hand and my intention is to install it just before the circuit breaker.
I have seen many designs with a disconnector switch , used for isolation purposes, installed just before circuit breakers or switch fuses? Am I in the right direction?
Thanks.
Guardiano





RE: Motor Starter
The NEC contains definition of "within sight of".
If this is not in NEC-land, I basically have no idea.
David Castor
www.cvoes.com
RE: Motor Starter
A photo would help - if there was one attached the link has gone bad.
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If we learn from our mistakes I'm getting a great education!
RE: Motor Starter
These installations were replaced with combination starters (a fused safety switch or circuit breaker in one enclosure) and Motor Control Centers which also have lockable disconnecting means.
As far as I know, a safety switch with lockable operating mechanism and lockable cover is still acceptable to comply with the disconnecting provisions of the electrical code and safety codes.
Bill
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"Why not the best?"
Jimmy Carter
RE: Motor Starter
Starter = On-Off device PLUS overload protection. Can be manual or magnetic.
Combination Starter - Magnetic Starter PLUS dedicated short-circuit protection, generally a MCCB or Fused Disconnect that also serves as Disconnecting Means for the Starter.
Basic NEC rules also require another disconnecting means within sight of the motor, but there are some exceptions to this.
David Castor
www.cvoes.com
RE: Motor Starter
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RE: Motor Starter
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Motor Starter
Guardiano