24 VAC GFI Required??? Shock Hazard?

[mjwalsh]

HELP------ I am being ganged up on in the final stages of a car-dog wash remodeling process. My Bismarck electrical contractor confirmed that the local Bismarck electrical inspector is requiring the coin box 24 VAC circuit & 24 VAC vending equipment out in all potentially wet areas such as car washes or outdoors & even dog washes to have a Ground Fault Interruptor installed. All 120 VAC items in the wash area such as lights & blowers etc. have a GFI circuit breaker so that has been addressed & is a non issue.

Since it appeared to be an easy accommodation a GFI was installed on the circuit to all the 24 VAC items. The problem is the electronics generates a greater amount of voltage leakage than the SUPER SENSITIVE 5 milliamps of the GFI. So guess what---the GFI trips & we are out of business unless a huge amount of expense is invested experimenting with other UL approved 24 VAC components.

My electrical contractor says that the State of North Dakota Electrical Board tends to come down even harder & he says that there is no greater authority than the State Electrical Board. The electrical contractor tends to have the reputation of being the oldest & highest ranked electrical contractor here in Bismarck. The contractor says that they have done the wiring for full services carwashes & the GFI for 24 VAC had not been required before but it is now required for all new & remodels.

I tried to explain to the inspector that it is impossible to completely seal the 24 VAC off because some openings are necessary. I also explained there is the chance the public could deliberately spray into the necessary openings but because it is only 24 VAC & it is fused with a 5 amp fuse there is no danger. He insists the code requires UL Nema Wet enclosure even for 24 VAC.

 

[mjwalsh]

24 VAC GFI Required??? Shock Hazard? Continued.

Continued from previous post

I asked to speak to the chief building inspector here in Bismarck who had granted the original permit & he said that the chief is not certified in electrical work so the chief would not be qualified to make that specialized judgement.

 

[ken-pro]

Being from Canada, our standards are probably a little different, but I can tell you what we have to do to satisfy inspectors here.

All equipment that connects to a voltage source greater than 32 volts must have an appropriate inspection and sticker - While the low voltage components themselves do not require approval the transformer setup does.

Our inspector requires us to use a 'Class 2' low voltage circuit - This is a special type of low voltage circuit with either a certified transformer OR specific fusing, labeling, grounding etc...

Because a transformer is a big block of copper and iron it would be possible for high voltage to travel to the low voltage circuit in the event of a transformer failure - This would be bad as there could potentially be 220 or 440 volts in a low voltage panel.

To prevent this we are required to:
Use a CSA / UL approved transformer and fuses etc...
Fuse the primary (High voltage) side of the transformer
Fuse the secondary (Low voltage) side of the transformer
Ground the body of the transformer
Ground the Secondary Neutral
Label all fuses OR use Tamper Proof Fuses

Building a low voltage circuit this way makes it quite safe, and makes it impossible for high and low voltage to cross at a faulty transformer. The grounding of the secondary neutral also eliminates floating and stray voltage, and is standard on most car wash setups that I've seen (Although not all of them). I'm not sure if you are setup this way, but I'm hoping this info might help you.

I have never heard of using a GFCI for a 24 volt setup, but anything is possible I guess.

 

[mjwalsh]

Thanks Neighbor to the North --- Kevin,

All the requirements that you listed have been met. Everything you said is consistent with other credible information that I have gathered. As a distributor & one who works closely with manufacturers & insurance companies you are very credible. You among many others, both nationally & internationally, especially would have a compelling interest to strike a balance between safety & unnecessary expense & the known fact that GFIs can be too sensitive with certain types of equipment. Unexpected & unnecessary tripping of the 24 VAC controls in our industry could have all kinds of negative implications & could in themselves creat a hazard with unexpected sudden power loss. For example, to totally cover the circuit the battery backup or generator source would also have to be included with a GFCI breaker. For those less familiar, a GFI 110 VAC is the outlet version of the ground fault interruptor. GFCI is the breaker verson.

I am tempted to take my shoes off in front of the inspector----stand in water---- & have a coworker stick the fused hot 24 VAC on the stainless steel surface while I am touching it to prove that the level of risk is acceptable.

 

[rph9168]

I once saw a demostration for a GFI where a guy held on to a live wire and jumped into a swimming pool. Luckily it worked and I bet he sold a lot of GFI's that day. Not sure I would try it but you are welcome to give it a go.

 

[mjwalsh]

I once saw a demostration for a GFI where a guy held on to a live wire and jumped into a swimming pool. Luckily it worked and I bet he sold a lot of GFI's that day. Not sure I would try it but you are welcome to give it a go.

I said I was tempted not that I would actually do it of course there might be people who might start chanting hurry up "Go for it".

Seriously, does that mean they actually guarantee that electrocution can not happen with a GFI? If it only helps to minimize the risk, it seems that a shower or tub area with a 110 VAC GFI close by could be a decision that would yield a greater risk than having 24 VAC close by. It could actually be a worthwhile University or Independent Study instead of people shooting from the hip.

 

[mjwalsh]

I see where either acronym GFCI & GFI turns out to be used for both the breaker approach & & for the individual electrical outlet approach. GFCI acronym appears to be more used for the breaker version.

 

[Randy]

Is the equipmnt you installed UL/ETL listed? In Washington state your screwed if you try to install anything that isn't UL/ETL listed. There's a new car wash that I know of that has a reclaim system installed that's not UL/ETL certified. The inspector will not sign off on his electrical permit and now the state is talking about fining him $100 per day until it's removed or certified. Both the distributor and the reclaim equipment manufacture have gone bankrupt so now he’s left holding the bag.

 

[mjwalsh]

Randy,

In Washington State would the inspector pass if all the components are UL approved within a 7 foot by 20 inch by 7 foot height stainless steel enclosure. Would they say "no go" if a customer could potentially deliberately spray into the opening on our bill acceptor & coin acceptor? Would they say "no go" because they were concerned about the rubberized coils of a few of our kip or dema solenoids could potentially get splashed on?

Keep in mind that the stainless steel enclosure is the only issue & there is no voltage greater than 24 VAC in this area. The fuse(110 VAC side) on one of the transformers is one half of an amp & on the one that serves the car wash solenoids & the acceptors etc is only 1 amp on the primary 110 side. The craziest part of this ordeal is that the enclosure is in the dog wash portion of the car wash & 24 VAC transformers are located over 10 feet away in a 100% dry area which is behind our laundry clothers dryers. If Bill wants to move this post to the Pet Wash Forum it would be Ok. I posted on this portion because of what the electrical contractor said that GFIs would be required on each circuit for all future car wash coin boxes & outdoor entrance payment boxes for the drive through car washes even if these boxes contain no voltage over 24 VAC!


I did find out that it is a scientifically proven fact that even while standing in water with bare feet & touching the hot &/or both the hot & neutral the human body has high enough ohm resistance so the shock will only affect or be felt by the skin where it is touched. Higher voltages than 40 can potentially do some damage & even fatality though. I also found out that GFIs have a significant over 20% failure rate & that is why they require people to constanly test & reset them to make sure they do not have just the illusion of safety vs an actual safety gain.

 

[mjwalsh]

Previous post continued.

Everytime we as an industry give these inspectors a way to not use better sense we lose a little more of our livelihood! There should be some check & balance to protect us from an inspector who is not putting the facts together & using the UL/ETL argument unnecessarily. To allow that would open the door for every time we improve on the OEMs product---- unnecessary red tape would occur. Randy, based on the information about 24 VAC only & no other public safety hazards----would you not use your position with the Car Wash Association to make any effort to stop the inspector clique from get away with really poor judgement?

 

[mjwalsh]

coin box enclosure people at risk?

I would think leaders or people involved in any coin box enclosures, which nowadays have more openings than ever, would be concerned about legal precedents that tend to gradually creep from one state to another.

On the other hand, if people involved in coin boxes are absolutely sure from testing that GFCIs will not cause unnecessary tripping of the breaker or outlet, then in that case don't be concerned about what I have posted. In my case, the GFI is tripping. I have invested in an over $400 device on its way UPS next week that supposedly measures the leakage between hot & neutral ---- in an effort to isolate what is causing the over 5 milliamp trip condition.

 

[ken-pro]

MJ - I have been thinking about our phone discussion last week. I would suggest you remove the connection between the primary and secondary neutral terminals on the transformer. This connection is usually used to prevent a floating voltage, but grounding the secondary side of the transformer does the same thing. Removing this connection will allow the primary and secondary to be isolated, and may prevent the GFI from kicking out - Which would solve your problem.

Also - Is this system UL/ETL approved? There are authorities who will perform a special inspection on a single piece of equipment for a somewhat reasonable fee - As a small equipment manufacturer this is how I get my equipment approved here in Canada.