Rapid Shutdown using E-stop and Electrically Operated Breakers

[kingpb]

Can you use a dedicated E-Stop (Properly labeled) located outside at the service entrance to open Switchboard electrically operated breakers that are connecting the PV arrays to the main building switchboard. In this case I have two arrays connected to a switchboard using two power circuit breakers.

 

[petersonra]

You can certainly do it. Whether it meets the code requirements for an emergency shutdown is something else.

 

[petersonra]

You can certainly do it. Whether it meets the code requirements for an emergency shutdown is something else.

I looked in article 691. It includes this verbiage.

TURN RAPID SHUTDOWN SWITCH TO THE “OFF” POSITION

I don't see how you could claim that depressing the estop PB is the same as turning a switch.

 

[kingpb]

I don't see how you could claim that depressing the estop PB is the same as turning a switch.
[/QUOTE]

Valid Point, I would need to specify an NEC compliant switch; doing a quick Google, looks like the major manufacturers do make them

 

[jaggedben]

A pushbutton is totally a switch. Whether it clearly indicates its position is a matter of how it is constructed and marked.

 

[petersonra]

A pushbutton is totally a switch. Whether it clearly indicates its position is a matter of how it is constructed and marked.

Just how would you turn a push button to the off position? The code very clearly uses the term turn.

 

[GoldDigger]

Just how would you turn a push button to the off position? The code very clearly uses the term turn.

You are saying that you could not use a toggle switch? That does not turn either. Maybe they do not want a handle sticking out that can be accidentally hit?

 

[petersonra]

You are saying that you could not use a toggle switch? That does not turn either. Maybe they do not want a handle sticking out that can be accidentally hit?

It does use the word turn.

 

[GoldDigger]

It does use the word turn.

But we turn off a light switch even when it is a toggle or even a push button.
Agreed, not exactly the same as turn to the off position.

 

[kingpb]

Probably one of those AHJ questions to install what they want.

I personally don't see the difference between an E-stop to kill the main on the main service, and to do the same thing on the PV system; but the fact they specifically worded it to "turn" makes me leary.

The only thing I can think of is that a pushbutton is not inherently obvious that it has been pushed from a distance, or it could be pushed in, then pulled back out. A turned switch to off position is very obvious and verifiable.

 

[petersonra]

Probably one of those AHJ questions to install what they want.

I personally don't see the difference between an E-stop to kill the main on the main service, and to do the same thing on the PV system; but the fact they specifically worded it to "turn" makes me leary.

The only thing I can think of is that a pushbutton is not inherently obvious that it has been pushed from a distance, or it could be pushed in, then pulled back out. A turned switch to off position is very obvious and verifiable.

I doubt they actually thought it out that far.

My opinion is that a shunt trip breaker for this kind of application introduces an additional hazard in the event of fire. What happens if the fire destroys the power supply being used for the shunt trip/ Then you push the PB or turn the switch and nothing happens.

 

[paulengr]

I doubt they actually thought it out that far.

My opinion is that a shunt trip breaker for this kind of application introduces an additional hazard in the event of fire. What happens if the fire destroys the power supply being used for the shunt trip/ Then you push the PB or turn the switch and nothing happens.

UV trip, too. Problem solved.