# gas pump kill switch



## Galt (Sep 11, 2013)

stop sw in series with contactor aux. pole and coil. will also need start switch.


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## papaotis (Jun 8, 2013)

sounds a little more complicated than i was told by owner! i will check into it more though.


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## frenchelectrican (Mar 15, 2007)

papaotis said:


> ive been asked to install that energency switch at a convenience store in a small town. never done one. simply aint possible the way it was described to me. any quick pointers on how this done is easily?


Papaotis.,,

It is pretty straight foward on the set up.,

the emergecy switch is very simple.,

you will need a shunt breakers or use subpanel with one breaker to feed the gas pump panel and wired all the emergecy stop in series so if any of the switch tripped it will trip the breaker to shut the power off.

But check with your local codes I am not sure what they are required in your location but majorty of the details will be in the NEC but I could not remember which section it is but I do know it in two spots .,

the number of emergercy stop button or switch useally at least two I know for sure one inside and one at outdoor location maybe more if required.


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## papaotis (Jun 8, 2013)

thanks frenchie, i am going to have to study this more. i was told that one panel (there are three) controlled all the outside stugg, but according to the labeling that is definetly not the case! he wanted the switch to kill everything outside, i dont see it happening :blink:


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## MechanicalDVR (Dec 29, 2007)

papaotis said:


> thanks frenchie, i am going to have to study this more. i was told that one panel (there are three) controlled all the outside stugg, but according to the labeling that is definetly not the case! he wanted the switch to kill everything outside, i dont see it happening :blink:


Just like French said, it is always done with shunt trip breakers. If not one for the main panel that feeds all the others then you can install shunt trip breakers in each panel and use a multi pole contractor or series of relays operated by the stop switch to trip each shunt trip breaker. Everything out at the fuel islands has to shut off with one switch.


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## frenchelectrican (Mar 15, 2007)

papaotis said:


> thanks frenchie, i am going to have to study this more. i was told that one panel (there are three) controlled all the outside stugg, but according to the labeling that is definetly not the case! he wanted the switch to kill everything outside, i dont see it happening :blink:


Ya welcome Papaotis .,,

the quickest way if you are famauir with shunt breakers it pretty much giveaway clue but over the years whoever done to that place can really mess up set up.,

everything outside ??? hope not those them light at all.,, that the only item that stay on when the emergecy switch or button been hit.,
the gas pumps will shut off plus storage tank transfer pump will go off same time as the em switch or button been hit ., that I do know but anything else it kinda up to the fire marshal or inspector.,,

I know my Philippine electrical code stated here the gas pump and underground tank pumps must be shut off with emergecy switch or button tripped but the light useally stay on ( only the ceileing lumainaires or pole lumaiaires can stay on but lights on pump itself ., no not with emergecy circuit)

overall basically two most common verison it been done is use shunt breakers or use the contractor to feed the panel.


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## papaotis (Jun 8, 2013)

yeah, thats what i was thinking is that it should not shut off EVERYTHING outside!


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## MechanicalDVR (Dec 29, 2007)

papaotis said:


> yeah, thats what i was thinking is that it should not shut off EVERYTHING outside!


a) All electrical installations shall comply with the edition of NFPA 70 in effect at the time of installation of the electrical equipment and shall further comply with the applicable requirements of Section 175.425. 

b) Every self-service motor fuel dispensing facility shall maintain a control station in a location readily accessible to the attendant. Separate fueling areas more than 100 feet apart and designated by signage so indicating may have separate control stations if each separate fueling area complies with this Subpart B and 41 Ill. Adm. Code 174, 175 and 176.

c) A method that does not require coins or currency to activate shall be provided for the attendant to contact the fire department.

d) Conspicuously marked and easily accessible emergency shutoff switches must be provided at each facility and shall be:

1) Located so that at least one emergency shutoff is at least 20 feet but not more than 100 feet from each dispenser. 

2) Interconnected so that activation of one shutoff activates all the shutoffs whenever more than one emergency shutoff switch is provided.

3) Equipped with an additional emergency shutoff at the control station, which shall be conspicuously marked and readily accessible to the attendant, whenever the control station is less than 20 feet from any dispenser or a security booth is provided for the attendant. The emergency shutoff shall be located in a position to allow all dispensing devices to be readily visible to the attendant, or as approved by OSFM, and where a security booth is provided, the control station and emergency shutoff shall be inside the security booth.

e) Power for illumination of dispensing areas required by this Subpart B shall not be affected by activation of any of the electrical shutoffs when the illumination is located outside of hazardous (classified) locations or is intrinsically safe.

f) Resetting from an emergency electrical shutoff condition shall require manual intervention by the owner or attendant and shall be accomplished only after the condition that caused it to be activated has been corrected.

g) All dispensing units shall be readily visible from the control station without assistive devices. However, as an alternative, in the event that the attendant's view of a dispenser is permanently obstructed, or if a dispenser is located so that activity at the dispenser is not readily visible, closed-circuit cameras that provide a view of each side of the dispensing unit and project an image on a screen at least 6 inches in diagonal located at the control station may be used. The cameras shall be allowed to sweep to provide a view of multiple dispensing locations, but must provide a view on the screen of each dispensing unit at least every 30 seconds. In lieu of the closed-circuit camera, the facility may elect to have an emergency electrical shutoff switch that shall be located at least 20 and not more than 50 feet from the dispenser that has a permanently obstructed view. Using an emergency shutoff switch in lieu of the closed-circuit camera pursuant to this subsection (g) must be approved in advance by OSFM. If a closed-circuit camera or viewing screen is inoperable and cannot provide surveillance of dispensing units to the attendant at the control station, and an emergency electrical shutoff switch has not been approved by OSFM and provided in lieu of the camera as provided in this subsection (g), self-service dispensing of fuel at these dispensers is prohibited.


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## Cow (Jan 16, 2008)

MechanicalDVR said:


> Just like French said, it is always done with shunt trip breakers. If not one for the main panel that feeds all the others then you can install shunt trip breakers in each panel and use a multi pole contractor or series of relays operated by the stop switch to trip each shunt trip breaker. Everything out at the fuel islands has to shut off with one switch.


I've never used a shunt for a fuel island and have never seen one installed that way.

We use contactors with an e-stop wired in series with the coil.


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## MechanicalDVR (Dec 29, 2007)

Cow said:


> I've never used a shunt for a fuel island and have never seen one installed that way.
> 
> We use contactors with an e-stop wired in series with the coil.


It's normally shunt trips out this way. If you use a contractor, is it a manual reset contractor?


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## Cow (Jan 16, 2008)

MechanicalDVR said:


> It's normally shunt trips out this way. If you use a contractor, is it a manual reset contractor?


The e-stops used are of the 2 position push pull maintained variety. So when the e-stop gets pulled back out, the coil is re-energized and the fuel system is powered again.


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## frenchelectrican (Mar 15, 2007)

Cow said:


> The e-stops used are of the 2 position push pull maintained variety. So when the e-stop gets pulled back out, the coil is re-energized and the fuel system is powered again.


In my area we can use either way but most gas station I dealt with it useally have 2 postion but however it do have a key to get it back out so sorta like a saftey step to verify it to make it safe to get it back on.


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## MechanicalDVR (Dec 29, 2007)

Cow said:


> The e-stops used are of the 2 position push pull maintained variety. So when the e-stop gets pulled back out, the coil is re-energized and the fuel system is powered again.


I was under the impression that it needed to have a manual reset and not just pulling the button back out.

"Resetting from an emergency electrical shutoff condition shall require manual intervention by the owner or attendant and shall be accomplished only after the condition that caused it to be activated has been corrected."

*To me that was the whole reason for the shunt trip breaker, it couldn't just be reset by a customer.*


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## hardworkingstiff (Jan 22, 2007)

frenchelectrican said:


> Papaotis.,,
> 
> It is pretty straight foward on the set up.,
> 
> ...


If you do it with shunt trip breakers and you lose control power, you no longer have a working E-stop and you don't know it because everything keeps working.

If you use a relay and let the control circuit go through the E-stops, then if you lose control power the relay drops out and someone knows to fix the E-stop circuit.

IMO, shunt trip breakers should not be allowed for this application.


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## hardworkingstiff (Jan 22, 2007)

MechanicalDVR said:


> I was under the impression that it needed to have a manual reset and not just pulling the button back out.
> 
> "Resetting from an emergency electrical shutoff condition shall require manual intervention by the owner or attendant and shall be accomplished only after the condition that caused it to be activated has been corrected."
> 
> *To me that was the whole reason for the shunt trip breaker, it couldn't just be reset by a customer.*


To meet that requirement, I wired the contactor like a motor starter start/stop station with the start button under the attendants control and the E-stop is wired like the stop button of the motor starter example. So it's easy to have just one start location and as many as you want stop locations.


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## splatz (May 23, 2015)

Could you use SPDT E-stop switches? You could wire the Run terminals in series with the motor starter, the Stop terminals in parallel with the shunt trip terminals. This won't run if any switch is in the Stop position, and won't restart until the switch is returned to the Run position AND the breaker is reset.


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## Big John (May 23, 2010)

I know shunt-trips are common for E-stop and it's a widely accepted practice, but it's a fail-dangerous design. If I were responsible for coming up with how this safety system operated, I would want one where any interruption of the curcuit caused the pumps to shut down.

The best (and most expensive) option is what Splatz suggested: Both shunt-trip and contactor controls.

Alternately, I would put in contactors with a seal-in relay that could only be reset with a button behind the attendants station, then protect it with a regular breaker.


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## wcord (Jan 23, 2011)

The shunt trip to shut down the panel is one way.
we've done a few garages where the E-stop was tied into the Veeder Root system. That way only the pumps were turned off


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## inetdog (Apr 13, 2016)

Do you usually wire the emergency stop to also interrupt the neutral, or do you reserve that function only for the maintenance disconnect?


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