Emergency medical services garage gfi

[charlie b]

Originally Posted by robert d

The EMS can't be having this happen. Life saving equipment needs to be charged.

You have accidentally stepped into a favorite topic of mine (i.e., the notion of "emergencies"). So before I proceed, let me say "welcome to the forum."

The tripping of the GFCI device, and the resultant delay in re-charging the "life saving equipment," is not in and of itself a threat to life. It is an inconvenience, to be sure, having to reset the trip, or look for a long extension cord so that they can plug the equipment into some other outlet. But nobody is at risk of dying. So let us keep in mind that there is a difference between an emergency and an inconvenience.

Do you know what is a threat to life? A piece of equipment (with or without big rubber tires) that has a ground fault path that permits enough leakage current to trip a GFCI. When a GFCI trips, it often means that some person's life just got saved. That is its job. So when a customer complains that a GFCI keeps tripping, the solution is not to circumvent the GFCI device (as is often done, I fear), but rather to fix the equipment, so that the GFCI will not have any leakage current to sense.

[nhfire77]

I've been in the Fire Service for 15 years. All the older truck charging GFI's trip now and then. Specifically why i do not know. What I do know: The GFI's get replaced, the trucks get fixed, but it keeps happening.

I think the GFI's are just overworked. Plugging and unplugging, a lot of times there is more than one vehicle on the same circuit.

When a one of the GFI's are replaced, it seems to alleviate the problem, for a while (a few years), then it comes back. They don't get spec grade products, we get the standard grade (budget). Maybe a better made product?

[dbuckley]

If the tripping of GFCIs is a big issue in its own right ("The EMS can't be having this happen. Life saving equipment needs to charged") then there needs to be an alarm fitted so that if the charging power fails then someone is made aware of it and is responsible for ensuring the vehicle gets charged ior if that is not possible, then arrangements for an alternative vehicle are made.

This is a different issue to the GFCI tripping - two seperate problems. You can never guarantee the GFCI (or OCPD for that matter) wont trip.

[cruzJD]

I have run into this before. There are a lot of ambulances that have an inverter pre installed so they can charge there stuff when needed. If you’re up for the job check the wiring to the inverter. I found 4 units with a miss wired inverters form the factory; we rote a report of the issue and was fixed by the installers (2 different companies). I have found receptacles can be loose and end up touching the sides of the box that we think was the problem.

The few units that have had block heaters had a plug in the grill. Most units sit in a bay that’s kept in the 60’s. Where I’m at they will use the block heaters during the winter where there on a site for long periods of time and are on stand by.

The cord and plug assemblies take a lot of abuse. Some of the newer units have an anti drive off thing that will spit the cord out when the motor is started. I have seen a lot of people that will jerk the cord out not pull on the cord end.

I do not like to install the pull down cords for this application. I would rather hang a cord form the ceiling. This lets me know it will not be walked on or tossed on to the floor repeatedly.

[mcclary's electrical]

Originally Posted by cruzJD

I have run into this before. There are a lot of ambulances that have an inverter pre installed so they can charge there stuff when needed. If you’re up for the job check the wiring to the inverter. I found 4 units with a miss wired inverters form the factory; we rote a report of the issue and was fixed by the installers (2 different companies). I have found receptacles can be loose and end up touching the sides of the box that we think was the problem.

The few units that have had block heaters had a plug in the grill. Most units sit in a bay that’s kept in the 60’s. Where I’m at they will use the block heaters during the winter where there on a site for long periods of time and are on stand by.

The cord and plug assemblies take a lot of abuse. Some of the newer units have an anti drive off thing that will spit the cord out when the motor is started. I have seen a lot of people that will jerk the cord out not pull on the cord end.

I do not like to install the pull down cords for this application. I would rather hang a cord form the ceiling. This lets me know it will not be walked on or tossed on to the floor repeatedly.

We did the training center in orange. They have the auto ejectors. The cord reels I bought would not eject properly. I had to relpace the cord end. I had reels from the ceiling, like you said. The cord won't lay on the floor and get run over.

[cruzJD]

I’m going to guess that they have the auto ejector that has a plastic pin that pushes out the plug. They also make an air ejector but they were more popular on fire trucks witch also had a pre charge air house for the braking systems.

As far as the plug ends not working with the auto ejectors I drove down to one of the EMS builders (we have 3 in town) and found out what plug bases they recommended. I don’t know off the top of my head what the part number was but I ordered a case of them at our shop.

[nhfire77]

The auto ejectors generally, stink, from what I've seen. Just add a 1 foot cord pig tail between the main cord and the truck, so when the inevitble occurance of a failure of removal before take off, you drive away with a pigtail attachEd to the truck. Every once in a while the cord ends have to be remade. That is cheaper then a broken auto ejector.

Just my 2 cents.

[Cow]

I'd probably start first by megging the wiring from L-Gr and N-Gr before calling it a GFCI problem. I'd think that'll help narrow it down right away.

[massfd]

Not the exact problem you are having but similar, Our cord reels are not GFCI protected. The Ambulance has a 4 space panel with 3 square D GFCI breakers located behind the drivers seat. We would find a few of the breakers tripped at least twice a week.

Turns out that the panel was mounted sideways so the breakers where vertical, in the vertical position the breakers will trip from the vibration and shock of over the road travel. Spun the panels around so the breakers are now horizontal and the problem was cured.

Ever want to try it, take a Square D GFCI and hold it in your hand with the load terminals facing down. Now smack it on the palm of your hand, It will trip. Does not take much to trip them vertical, try it again horizontal and you realy need to wack it hard to trip it.

[cruzJD]

Thanks massfd for the update. I had not run into that before and defiantly something that I need to remember.