Shunt trip breaker

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KMark5710

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Had an electrical contractor stop by and ask this question today. He has a 480-volt panel with a shunt trip breaker. The controls for the shunt trip breaker are 120-volt. He wanted to know if that would be an issue. He was concerned about having 120-volts present in the 480-volt panel whenever someone turned off the panel's main breaker. Any thoughts? Where can I find this in the code?

My immediate response was to place a warning tag about control power being present.
 
augie47

augie47

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Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
In the sitution with the panel I know of no requirement, but if he's concerned he can add a warning plaque such as the one mentioned in 430.75
Many shunt trip breakers are activated under abnormal conditions and often by momentary devices so the voltage is seldom present.
 
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