# engine block heater trips gfi



## BlackHowling (Feb 27, 2013)

Heater coil may have a little leakage causing gfi to trip


----------



## finster (Nov 16, 2013)

BlackHowling said:


> Heater coil may have a little leakage causing gfi to trip


Its brand new though. And its been a pattern with his other trucks.


----------



## Big John (May 23, 2010)

If you've got a good GFCI tester, confirm the proper trip point of the GFCI:










Or else, just move to a different GFCI and see if the problem follows it. It if it does, the block heater has a >4mA ground fault.


----------



## oliquir (Jan 13, 2011)

check resistance with meter between hot and ground on heater, you should get infinite, even if it is brand new it can be defective


----------



## Wirenuting (Sep 12, 2010)

We had them here years ago. When the block heaters went bad it hurt like a mother some mornings until we installed GFCI's. 
You can guess what was wrong.


----------



## TOOL_5150 (Aug 27, 2007)

Wirenuting said:


> We had them here years ago. When the block heaters went bad it hurt like a mother some mornings until we installed GFCI's.
> You can guess what was wrong.


You didnt have shoes on.


----------



## Wirenuting (Sep 12, 2010)

TOOL_5150 said:


> You didnt have shoes on.


 We parked the trucked nose to tail and touching 2 was shocking at times. The guy in the garage who made the cords for the plugs was nice enough to solidly ground the trucks frame. The bad part was the conduit that ran down the walls and loading dock was rotted and falling apart in spots. There was no ground wire run back to the panel.


----------



## TOOL_5150 (Aug 27, 2007)

thats really not a good situation right there.


----------



## chicken steve (Mar 22, 2011)

95% of my _'gfci tripping'_ calls are simply due to them doing their job

in fact, i really think there should be a _'thank your gfci day' _ for all the incessant complainers out there to realize they may not have been around to _beeeaatch _w/o them


~CS~


----------



## Big John (May 23, 2010)

chicken steve said:


> 95% of my _'gfci tripping'_ calls are simply due to them doing their job.


 True of virtually every protection scheme I can think of: GFCIs, fuses, motor overloads, breakers, protective relays, you name it. Rule #1: It's most likely not a problem with the protective device.


----------



## BBQ (Nov 16, 2010)

Big John said:


> True of virtually every protection scheme I can think of: GFCIs, fuses, motor overloads, breakers, protective relays, you name it. Rule #1: It's most likely not a problem with the protective device.


But what is depressing is that often the same people who would never even consider doing away with any of those items have no problem with getting rid of the GFCI.


----------



## TOOL_5150 (Aug 27, 2007)

BBQ said:


> But what is depressing is that often the same people who would never even consider doing away with any of those items have no problem with getting rid of the GFCI.


Thats not depressing, thats natural selection.


----------



## Deep Cover (Dec 8, 2012)

I installed an outside GFI for a block heater a couple years back. Months after, our office person called me and asked why I put a GFI in for the block heater. I said, well, because it's required to be a GFI. She told me that I had to go back and change it out to a regular receptacle because most block heaters will trip a GFI. She also told me that an inspector told them it was OK.

I told her to have someone else do it. She did. Not for this reason in particular, but I do not work there anymore.


----------



## Cl906um (Jul 21, 2012)

i know its off subject a bit, but in my house my garage door openers, my basement freezer, and sump pump are not on gfi's. to me, i want all these systems to work. i have heard that newer motors aren't supposed to nuisance trip. why chance it. whether it being a buttload of spoiled meat, or having to get out of my car when its snowing to beat hell, to come home to a flooded basement. i liked the old ways. have a single outlet for each. maybe i will do assured grounding quarterly on all these...:thumbup:


----------



## wendon (Sep 27, 2010)

cl219um said:


> i know its off subject a bit, but in my house my garage door openers, my basement freezer, and sump pump are not on gfi's. to me, i want all these systems to work. i have heard that newer motors aren't supposed to nuisance trip. why chance it. whether it being a buttload of spoiled meat, or having to get out of my car when its snowing to beat hell, to come home to a flooded basement. i liked the old ways. have a single outlet for each. maybe i will do assured grounding quarterly on all these...:thumbup:


Does your state have an exception for that?


----------



## Dan Wheeler (Nov 22, 2013)

I just had a call about a month ago or so saying their outside receptacle was not working.
Went there and found the hot wire was corroded.
Told them I had to put in a gfci and did.
Got call next day, saying their block heater was tripping it, they said anything they plug in would not work.

Went back thinking maybe faulty gfci, pressed reset and plugged stuff in, all worked fine, even ran my heat gun.

Told caretaker what was happening and they said to leave it, renter probably had their cord sitting in water, or block heater, was old diesel truck.


----------



## five.five-six (Apr 9, 2013)

chicken steve said:


> 95% of my _'gfci tripping'_ calls are simply due to them doing their job
> 
> in fact, i really think there should be a _'thank your gfci day' _ for all the incessant complainers out there to realize they may not have been around to _beeeaatch _w/o them
> 
> ...


When I was in the aquarium hobby I had some very long winded inter-webs arguments with people that hated GFIC, every now and then one of them would stop posting here or there. No obituary or nothing, they just stopped posting.


----------



## BBQ (Nov 16, 2010)

cl219um said:


> i know its off subject a bit, but in my house my garage door openers, my basement freezer, and sump pump are not on gfi's. to me, i want all these systems to work. i have heard that newer motors aren't supposed to nuisance trip. why chance it. whether it being a buttload of spoiled meat, or having to get out of my car when its snowing to beat hell, to come home to a flooded basement. i liked the old ways. have a single outlet for each. maybe i will do assured grounding quarterly on all these...:thumbup:


Yeah, for sure. 

It would be much better for you or a family member to get a shock or even killed vs replacing some spoiled meat or the hell of stepping out of the car in the snow.:jester:

I am sure you have the sump pump on battery back up and auto generator as well in case of utility failure. :whistling2:


----------



## BBQ (Nov 16, 2010)

TOOL_5150 said:


> Thats not depressing, thats natural selection.


As long as it happens to the person who takes out the GFCI I agree with you.














:jester::laughing:


----------



## HARRY304E (Sep 15, 2010)

BBQ said:


> But what is depressing is that often the same people who would never even consider doing away with any of those items have no problem with getting rid of the GFCI.


As long as other types of Receptacles are available they will keep doing it.


----------



## Cl906um (Jul 21, 2012)

wendon said:


> Does your state have an exception for that?


Nope


----------



## Cl906um (Jul 21, 2012)

BBQ said:


> Yeah, for sure.
> 
> It would be much better for you or a family member to get a shock or even killed vs replacing some spoiled meat or the hell of stepping out of the car in the snow.:jester:
> 
> I am sure you have the sump pump on battery back up and auto generator as well in case of utility failure. :whistling2:


This has been the norm for years. Probably lobbyists for gfi recepts making it the law of the land. Just like arc fault interrupters . Who can afford all that? Shoemakers kids go without shoes you know....


----------



## Big John (May 23, 2010)

There's evidence that GFCIs work, and it's easily proven. Never seen that with AFCIs.


----------



## Cl906um (Jul 21, 2012)

I have seen many motors nuisance trip gfi recepts. It used to be an exception to have single designated outlet for them. I have no idea why they changed it.


----------



## Cl906um (Jul 21, 2012)

BBQ said:


> Yeah, for sure.
> 
> It would be much better for you or a family member to get a shock or even killed vs replacing some spoiled meat or the hell of stepping out of the car in the snow.:jester:
> 
> I am sure you have the sump pump on battery back up and auto generator as well in case of utility failure. :whistling2:


There are 2300, 4160 volt motors all over mills, and nobody dies when they fault. What planet are you on? That's what the equipment ground is for.


----------



## Big John (May 23, 2010)

I have never seen a motor nuisance trip a GFCI. I have seen many motors trip GFCIs because they had legitimate ground faults. 

And your MV motors operate protection and shut down when they fault. A lot of LV equipment can develop ground faults without operating overcurrent, so the dangerous condition remains.


----------



## Cl906um (Jul 21, 2012)

Big John said:


> I have never seen a motor nuisance trip a GFCI. I have seen many motors trip GFCIs because they had legitimate ground faults.
> 
> And your MV motors operate protection and shut down when they fault. A lot of LV equipment can develop ground faults without operating overcurrent, so the dangerous condition remains.


I went to a guys cottage that inspector had me add a three way in his basement. I noticed the recept tripped when I plugged my drill in. I open the freezer and did it stink.reset gfi and left them a note saying do not eat. So I can say I seen it first hand. Supposedly newer motors aren't supposed to be as bad. Why chance it?


----------



## Big John (May 23, 2010)

The problem is the old motors are tripping GFCIs because they leak ground fault current, it's not really nuisance tripping. There are a couple documented cases of people being killed by their old fridges. 

The example I always use is think of a construction site: Guys running all kinds of motor-driven tools all over the place. If there was ever gonna be a place where nuisance trips would show up, it'd be there, and I never saw that problem.


----------



## Cl906um (Jul 21, 2012)

Big John said:


> The problem is, the old motors are tripping GFCIs because they leak ground fault current, there are a couple documented cases of people being killed by their old fridges.
> 
> The example I always use is think of a construction site: All those guys running all kinds of motor-driven tools all over the place. If there was every gonna be a place where nuisance trips would show up, it'd be there, and I never saw that problem.


You never seen a job site gfi trip? Man you are making me feel old. Been in the trade for twenty years. Seen gfi recepts on job trip tons. Mostly from being overloaded though. Trip before the breaker.


----------



## mbednarik (Oct 10, 2011)

GFCI receptacles do not contain any overcurrent protection at all. I just finished a 63,000 sq ft warehouse and they had me install 2 dedicated 120v receptacles for a portable stretch wrapping machine. Just a standard 5-15 plug on the machine so I installed GFCI receptacles. Spec for all of the other rec's were to be GFCI protected due to their employees frequently using extension cords, so I installed GFCI receps on those too. I got a call asking to remove the GFCI's because the machine trips them instantly. I have not been onsite yet to analyze the machine, but if I had to lay money on it there is something wrong with the machine.


----------



## Cl906um (Jul 21, 2012)

mbednarik said:


> GFCI receptacles do not contain any overcurrent protection at all. I just finished a 63,000 sq ft warehouse and they had me install 2 dedicated 120v receptacles for a portable stretch wrapping machine. Just a standard 5-15 plug on the machine so I installed GFCI receptacles. Spec for all of the other rec's were to be GFCI protected due to their employees frequently using extension cords, so I installed GFCI receps on those too. I got a call asking to remove the GFCI's because the machine trips them instantly. I have not been onsite yet to analyze the machine, but if I had to lay money on it there is something wrong with the machine.


I realize they have no over current protection. When they are loaded up with octopus of cords they seem to trip before the breaker though. Could just be some leakage current from all the tools running in combination.


----------



## mbednarik (Oct 10, 2011)

I have a customer which has 14 4 plex rec's scatter throughout his yard for Christmas stuff. He had many bad GFCI's and someone told him to install a GFCI breaker on that setup. I talked him out of the GFCI breaker for the cumulative leakage problem. I threw away the no name home depot GFCI's and installed some nice WR P and S GFCI's and all is better. They add had in use covers before but no drain holes at all.


----------



## Big John (May 23, 2010)

cl219um said:


> You never seen a job site gfi trip...?


 Not on a bunch of nuisance trips where there was no ground-fault involved. The majority of trips I ran into were easily identifiable as ground faults: 

_"You can't run your extension cords through the water; you can't use the drill you repaired with JB Weld; you shouldn't run that table saw you inherited from your great-grandfather."_


----------



## BBQ (Nov 16, 2010)

cl219um said:


> There are 2300, 4160 volt motors all over mills, and nobody dies when they fault. What planet are you on? That's what the equipment ground is for.


How many of those motors are cord and plug connected?:whistling2:


The reason the NEC pushes GFCIs for cord and plug connected loads is due to the grounding pin breaking off the cord cap or the wire EGC being broken.


----------



## BBQ (Nov 16, 2010)

cl219um said:


> I went to a guys cottage that inspector had me add a three way in his basement. I noticed the recept tripped when I plugged my drill in. I open the freezer and did it stink.reset gfi and left them a note saying do not eat. So I can say I seen it first hand. Supposedly newer motors aren't supposed to be as bad. Why chance it?


Let me follow your logic here, you have seen spoiled food in a freezer so you would not chance using a GFCI.

You do understand that if the freezer that is tripping the GFCI loses its EGC connection will become energized to the touch without the GFCI right?



> Two electricians have been charged in the death of Raul Hernandez at a Houston hotel swimming pool. Police said shoddy work by the electricians led to Hernandez's electrocution.





> The Houston Chronicle reported that the electricians have been charged with criminally negligent homicide.





> An investigation by police, the city's Public Works and Engineering Department and the Texas Department of Licensing and Regulation also determined the wiring to the pool light lacked a ground fault circuit interrupter......



http://m.ecmweb.com/around-circuit/electricians-charged-houston-pool-electrocution

More info here http://www.chron.com/news/houston-t...harged-in-electrocution-of-man-at-4968736.php

So which would you rather take a chance on, spoiled meat or a homicide charge?


----------



## Ultrafault (Dec 16, 2012)

BBQ said:


> So which would you rather take a chance on, spoiled meat or a homicide charge?


What kind of meat?


----------



## BBQ (Nov 16, 2010)

Ultrafault said:


> What kind of meat?


Good point. :laughing:


----------



## don_resqcapt19 (Jul 18, 2010)

I have as much confidence in the safety of an appliance with a three wire cord, where I know the EGC path is good, as I do in the safety of a GFCI protected appliance. The issue is the fact that the EGC path is often compromised or non-existent, so the code requires GFCI protection. 

In fact the EGC prevents the shock whereas the GFCI only limits its duration.


----------



## Semi-Ret Electrician (Nov 10, 2011)

cl219um said:


> You never seen a job site gfi trip? Man you are making me feel old. Been in the trade for twenty years. Seen gfi recepts on job trip tons. Mostly from being overloaded though. Trip before the breaker.


True, it's hard to tell a brick foreman his saw is bad.


----------



## Semi-Ret Electrician (Nov 10, 2011)

don_resqcapt19 said:


> I have as much confidence in the safety of an appliance with a three wire cord, where I know the EGC path is good, as I do in the safety of a GFCI protected appliance. The issue is the fact that the EGC path is often compromised or non-existent, so the code requires GFCI protection.
> 
> In fact the EGC prevents the shock whereas the GFCI only limits its duration.


True, now we have to install a GFCI in unfinished basements. 

It's a hand me down and has worked for years. 

A week later the GFCI trips and the HO wants to sue for $1000 worth of bad food.


----------



## BBQ (Nov 16, 2010)

Semi-Ret Electrician said:


> True, now we have to install a GFCI in unfinished basements.
> 
> It's a hand me down and has worked for years.
> 
> A week later the GFCI trips and the HO wants to sue for $1000 worth of bad food.


So lets say the same unit has a line to line fault that trips the breaker.


Would you still be concerned about being sued?


----------



## MTW (Aug 28, 2013)

don_resqcapt19 said:


> I have as much confidence in the safety of an appliance with a three wire cord, where I know the EGC path is good, as I do in the safety of a GFCI protected appliance. The issue is the fact that the EGC path is often compromised or non-existent, so the code requires GFCI protection.
> 
> In fact the EGC prevents the shock whereas the GFCI only limits its duration.


Good point. But doesn't GFCI add protection in those situations where only a 2-wire cord is present?


----------



## Semi-Ret Electrician (Nov 10, 2011)

BBQ said:


> So lets say the same unit has a line to line fault that trips the breaker.
> 
> 
> Would you still be concerned about being sued?


L-L faults don't occur every time a storm rolls over. IMO a good EGC would be better than a GFCI for this application, like a fire pump.

And if a customer looses a $1000 of food on something I worked on last week, that too would worry me.


----------

