burning out neutrals....

[Dg01501]

Ok so heres the issue...I work at dangelos part time and over the years we have had the same two steamers and randomly they would burn out the neutrals in the cord cap. The owner had tried to change plugs....cord caps....circuits. nothing has been working. So today I smelt an electrical burn smell and saw that the steamer cord cap was charred black. I shut the breaker off and tool the cord cap off and examined it. The connections were tight but the neutral wore going to the steamer was charred. So I decided to check the plug in the wall to see if that neutral was burnt up as well..it wasnt. Well there was another steamer running in the building so.I decided to get my meter out. I have a plug in device that allows me to read the amps on a circuit without splitting the wires. And I measured 15 amps on the hot....which is ok......but I was reading 120 amps on the neutral!!!!!!!! Why would this be happening. Bad steamer?? The breakers have never tripped cuz of this.

 

[kbsparky]

Maybe they had a neutral to ground fault in the equipment? Did you measure any current on that neutral with the equipment plugged in, and the power switched off?

 

[cadpoint]

Sounds like bad equipment, the only other thing I can suggest is US Consumer Product Safety Commission.

 

[defears]

Bad or no main bonding jumper at service or sub panel. Or rouge amperage from welders.

 

[kwired]

Ok so heres the issue...I work at dangelos part time and over the years we have had the same two steamers and randomly they would burn out the neutrals in the cord cap. The owner had tried to change plugs....cord caps....circuits. nothing has been working. So today I smelt an electrical burn smell and saw that the steamer cord cap was charred black. I shut the breaker off and tool the cord cap off and examined it. The connections were tight but the neutral wore going to the steamer was charred. So I decided to check the plug in the wall to see if that neutral was burnt up as well..it wasnt. Well there was another steamer running in the building so.I decided to get my meter out. I have a plug in device that allows me to read the amps on a circuit without splitting the wires. And I measured 15 amps on the hot....which is ok......but I was reading 120 amps on the neutral!!!!!!!! Why would this be happening. Bad steamer?? The breakers have never tripped cuz of this.

That is not possible unless maybe there is voltage on the equipment ground because a fault eleswhere, an open circuit in the EGC someplace, and a neutral to ground fault exists in the steamer. 15 amps incoming on the hot and 120 going back on neutral leaves 105 unaccounted for. It has to come from somewhere. Is there any current on the equipment ground conductor? Your line splitter probably does not give you a place to measure the EGC. Many of those devices have a single turn and a 10 turn place to clamp onto, make sure you did not mistakenly do that or your meter reading will be 10 times higher than the actual current - although you should have read 150 if everything was alright and that is what you did.

 

[mbrooke]

If the readings are correct there is a neutral to ground fault in the steamer along with an open or loose neutral at the service entrance or subpanel. If that is the case the neutral current is trying to get back to the source and is using any ground path it can find. This needs to be corrected because 120amps is a serious fire hazard on a 12 or 10 gauge wire.

 

[Dg01501]

I appreciate the feedback. I'm going back tomorrow night to double check and make sure I didn't use the wrong side of the meter. Otherwise if I was right ill definately check that neutral out. Thanks ill post my findings

 

[copper chopper]

might be something else

might be something else

as a former service truck driver I have encountered a similar case in a water heater.. since you said its a steamer then there may be a bad element on the unit and causes excessive current on the neutral but not on the hot to trio the breaker... after I replaced the element it was fine...........

 

[hurk27]

What is the voltage and current rating of this steamer?

Without knowing what kind of circuit is feeding this steamer something is not adding up.

I sat here and mapped out several diagrams trying to duplicate this and I only came up with one thing that would cause more current on the neutral then the hot on a 120 volt appliance, a lost neutral at the service will only produce more current on the grounding, faulting the neutral to ground will only cause the neutral to share the current with the EGC, but not increase the current over the hot, if the neutral is lost after the main bonding jumper such as if there is a service disconnect and a sub panel then there are other loads sharing this neutral from other circuits then I can see it, but then the EGC would also have this high current on it too?

One test you should do is to put your amp probe on the main incoming neutral at the sub panel feeding this equipment, if you get very little to no reading then you found the problem as far as the high current goes, but this is still saying there is a neutral to EGC fault in these steamers also that needs to be addressed? what is strange is that if you have un plugged these steamers you should have had a voltage reaction on any of the loads on this subpanel, as in any lost neutral situation the voltage on a heavily loaded phase will will drop and the voltages on the other phase will rise, how much will depend upon how balance this panel is, and with the info of this current it doesn't seem too balanced?

 

[WorkSafe]

I'll be the a$$ and ask if you, (apprentice electrician according to your profile), are the one performing this type of troubleshooting and work at a commercial business? I thought only licensed electricians can do commercial work? Seems like a liability the owner should not be taking, no offense.

 

[RCinFL]

Does the steamer also have a 240 vac feed? I don't know how big your steamer is but generating steam require a lot of power. 120 vac @ 15 amps limit on plug outlet is barely enough to run a typical household steam iron. Anything larger would need 240 vac.