Fuel Panel

[jap]

Power to a subpanel which feeds a fuel Island.
The 1p breakers in the subpanel are Switched Neutral.
The 2p breakers are standard.
This panel is being fed from a 2 pole 100 amp shunt trip breaker in the MDP.
An Emergency Power Off button located outside to activate the Shunt Trip.

Authority is siting this is a violation and the neural must be run through a contactor to physically disconnect the neutral to the Subpanel and the Shunt Trip is a violations since it does not disconnect the Neutral to the Fuel Panel.

Is this correct?

 

[iwire]

Yes it is correct.

514.11 Circuit Disconnects.

(A) General. Each circuit leading to or through dispensing equipment, including equipment for remote pumping systems, shall be provided with a clearly identified and readily accessible switch or other acceptable means, located remote from the dispensing devices, to disconnect simultaneously from the source of supply, all conductors of the circuits, including the grounded conductor, if any. Single-pole breakers utilizing handle ties shall not be permitted.

 

[Ragin Cajun]

This looks like one of those yes and no situations.

"Each circuit" does disconnect the hot and neutral via the 2 pole breaker, so the requirement is met - for "each circuit".

The code doesn't mention anything regarding the panelboard feeding the individual breakers for "each circuit". Am I drawing a fine line? Or, is the AHJ using an excessively broad brush?

RC

 

[iwire]

This looks like one of those yes and no situations.

"Each circuit" does disconnect the hot and neutral via the 2 pole breaker, so the requirement is met - for "each circuit".

The code doesn't mention anything regarding the panelboard feeding the individual breakers for "each circuit". Am I drawing a fine line? Or, is the AHJ using an excessively broad brush?

RC

Many, if not most modern dispensers have more than one circuit feeding them, that rules out individual breakers.

The last ones I worked on had three separate circuits running to each dispenser.

In that case they used one, 6 pole switch per dispenser to meet the requirement.

 

[jap]

The EPO button outside,shunt trips the 100 Amp Breaker feeding the subpanel, which contains all of the circuits, (Switched Neutrals for the single Poles) feeding the fuel equipment.
The concern was with the disconnecting the Feeder Neutral to the subpanel.

Even though you kill the 100 amp feeder to the subpanel which feeds all of the fueling equipment you havent disconnected the Neutral in the 100 amp feeder to the subpanel.
Although when you kill the power to the subpanel, one would assume there would be no Neutral Current to contend with.

By the wording it looks as though a means would be needed to physically disconnect the neutral from the MDP for the feeder to the subpanel,even though the shunt trip breaker has killed all the Ungrounded Conductors to the subpanel.

 

[jap]

when you shut off the individual breakers in the subpanel you are in fact disconnecting the neutral through the switched neutral breakers.
but
if you shunt tripped the feeder breaker to the panel in an emergency situation you have not disconnected the neutral if the branch breakers are still in the "on" posistion.

I've never thought of this, this way until now.

 

[kwired]

when you shut off the individual breakers in the subpanel you are in fact disconnecting the neutral through the switched neutral breakers.
but
if you shunt tripped the feeder breaker to the panel in an emergency situation you have not disconnected the neutral if the branch breakers are still in the "on" posistion.

I've never thought of this, this way until now.

The EPO button is nothing more than a control it is not a disconnecting means. It could be a normally open or held closed switch and drive a contactor instead of a shunt trip breaker, then it would be even more obvious that it is a control and not a disconnect.

The switched neutral breaker is a disconnect. The reason we disconnect the neutral in a hazardous location is if we are working on the equipment and we shorted the neutral conductor to a grounded object - if that neutral conductor had a little voltage on it for any reason (and they often do because of voltage drop on the service or feeder they are connected to) you have an ignition source for the hazardous location should it spark when it touches a grounded object. The EPO button is not for disconnecting the equipment so it can be worked on, it is for simply opening operating circuits to make equipment stop running in emergency situations.

A switched neutral breaker wouldn't necessarily have to be used on the branch circuits that do have them if there were other "disconnecting means" that interrupted the neutral.

 

[jap]

The EPO button is nothing more than a control it is not a disconnecting means. It could be a normally open or held closed switch and drive a contactor instead of a shunt trip breaker, then it would be even more obvious that it is a control and not a disconnect.

The switched neutral breaker is a disconnect. The reason we disconnect the neutral in a hazardous location is if we are working on the equipment and we shorted the neutral conductor to a grounded object - if that neutral conductor had a little voltage on it for any reason (and they often do because of voltage drop on the service or feeder they are connected to) you have an ignition source for the hazardous location should it spark when it touches a grounded object. The EPO button is not for disconnecting the equipment so it can be worked on, it is for simply opening operating circuits to make equipment stop running in emergency situations.

A switched neutral breaker wouldn't necessarily have to be used on the branch circuits that do have them if there were other "disconnecting means" that interrupted the neutral.

I understand and agree with all of the above. Every fueling area that I've seen has an EPO Button for Emergency Shutdown, which means its electrically activating something somewhere wheter it be a Shunt Trip Breaker or a Contactor or so forth to shut down all the power to the fueling area.. Therefore the device it is controlling must disconnect the neutral also.It would either have to be controlling a Contactor where the Neutral is switched through one of the poles, or, if a single phase feeder to the subpanel,I guess one could use a 3pole shunt trip breaker and switch the neutral through one of the poles. I wouldnt use the EPO as a disconnecting means to work on the equipment neither, but , that doesnt seem to take away from the fact that it seems whatever the EPO is controlling must disconnect the Neutral also. And that seems to be what the AHJ is siting.

 

[kwired]

I understand and agree with all of the above. Every fueling area that I've seen has an EPO Button for Emergency Shutdown, which means its electrically activating something somewhere wheter it be a Shunt Trip Breaker or a Contactor or so forth to shut down all the power to the fueling area.. Therefore the device it is controlling must disconnect the neutral also.It would either have to be controlling a Contactor where the Neutral is switched through one of the poles, or, if a single phase feeder to the subpanel,I guess one could use a 3pole shunt trip breaker and switch the neutral through one of the poles. I wouldnt use the EPO as a disconnecting means to work on the equipment neither, but , that doesnt seem to take away from the fact that it seems whatever the EPO is controlling must disconnect the Neutral also. And that seems to be what the AHJ is siting.

Where does it say a control device must interrupt all conductors including the grounded circuit conductor? If that were true than any contactor used for regular control would also have to interrupt the grounded conductor.

An EPO is not a disconnecting means, it is just a control device. An EPO near a piece of machinery (outside of a classified area) is no different. When you are servicing that equipment you do not LOTO the EPO you LOTO the disconnecting means for that equipment, as the EPO doesn't necessarily remove all energy sources, it simply opens things that were deemed necessary to stop the equipment.

 

[GoldDigger]

An EPO is not a disconnecting means, it is just a control device. An EPO near a piece of machinery (outside of a classified area) is no different. When you are servicing that equipment you do not LOTO the EPO you LOTO the disconnecting means for that equipment, as the EPO doesn't necessarily remove all energy sources, it simply opens things that were deemed necessary to stop the equipment.

I can see a possible source of confusion here, in that one could see the function of the EPO as being solely to stop the machinery from operating (the common understanding) or also to also remove all sources of power in the event of a fire of electrical origin.
The latter function would, strictly speaking, require interrupting the neutral too if (big if) there is a neutral fault somewhere in the system that has applied voltage to the neutral.
I am not arguing for this, just suggesting that this inspector may have that incorrect understanding (or, of course, have no understanding at all. )

 

[jap]

I can see a possible source of confusion here, in that one could see the function of the EPO as being solely to stop the machinery from operating (the common understanding) or also to also remove all sources of power in the event of a fire of electrical origin.
The latter function would, strictly speaking, require interrupting the neutral too if (big if) there is a neutral fault somewhere in the system that has applied voltage to the neutral.
I am not arguing for this, just suggesting that this inspector may have that incorrect understanding (or, of course, have no understanding at all. )

This is very well put and exactly where the confusion lyes.
He indicated that the 2p 100 amp Shunt Trip Feeder Breaker, which is activated by the EPO Button for emergency off purposes,does not disconnect the neutral to the fueling island in an emergency power off situation and I'd have to agree.
Although the 1p Switched Neutral Breakrs and the standard 2p Breakers in the subpanel are what are generally shut off to service the equipment not the main feeder to the subpanel where everything would go down.

 

[jap]

He's siting if the EPO is pushed and the branch breakers in the subpanel are still in the "On" Position, the neutral has not been disconnected,,,,,,, and in that particular scenario he is correct.

 

[texie]

Power to a subpanel which feeds a fuel Island.
The 1p breakers in the subpanel are Switched Neutral.
The 2p breakers are standard.
This panel is being fed from a 2 pole 100 amp shunt trip breaker in the MDP.
An Emergency Power Off button located outside to activate the Shunt Trip.

Authority is siting this is a violation and the neural must be run through a contactor to physically disconnect the neutral to the Subpanel and the Shunt Trip is a violations since it does not disconnect the Neutral to the Fuel Panel.

Is this correct?

As others have said, the inspector is correct. Art. 514.11 is pretty clear-you must disconnect ALL conductors.
As a side note, do you have any other circuits to the dispensers such as data and/video, etc? If so, they also have to be switched with the EPO.

 

[jap]

The Fuel Dispenser crew takes care of the cabling, although I dont know how they incorporate disconnecting that,that's their issue to contend with.

 

[texie]

The Fuel Dispenser crew takes care of the cabling, although I dont know how they incorporate disconnecting that,that's their issue to contend with.

Well, there may be more than one contractor involved, but the code requires all circuits to be switched by the EPO regardless of who does it.
That said, I realize this is frequently violated. But that does not change the requirements.

 

[jap]

Well, there may be more than one contractor involved, but the code requires all circuits to be switched by the EPO regardless of who does it.
That said, I realize this is frequently violated. But that does not change the requirements.[/QUOte

Water is a conductor also and there's a spout next to the gas pumps. We may have to shut it off also along with unplugging the speaker wires and disconnecting the Video Calbes.

 

[iwire]

Where does it say a control device must interrupt all conductors including the grounded circuit conductor?

It does not, but I don't think the OP has clarified how many circuits run to each dispenser.

If there is only one circuit to each disperser I agree the breaker alone may satisfy 514.11

However if there is more than one circuit per dispenser the breakers do not provide a simultaneous means of disconnection, therefore in the OPs case the EPO will have to do that job and it will have to open the neutral.

 

[texie]

It does not, but I don't think the OP has clarified how many circuits run to each dispenser.

If there is only one circuit to each disperser I agree the breaker alone may satisfy 514.11

However if there is more than one circuit per dispenser the breakers do not provide a simultaneous means of disconnection, therefore in the OPs case the EPO will have to do that job and it will have to open the neutral.

The EPO must open "everything", including neutrals.

 

[iwire]

The EPO must open "everything", including neutrals.

I don't see any wording that it has to be the EPO that does that.

 

[texie]

I don't see any wording that it has to be the EPO that does that.

514.11(B) or (C) refers you back to (A) which requires everything.
The real rub here is the new language in 2011 that makes it clear that "everything" even includes data, video, etc. Right now there are very few products available to accomplish this.