Another accidental 30 amp into 220

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joeshannallie

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Ok yes It happen again someone accidentally wired up a 220 outlet for a 30 amp plug in for rv travel trailer. Blowed fuse and capacitor on converter board. That has been repaired and everything works fine and as it should except the tv. Small flat screen connected to regular style 110 outlet in camper. No power from tv. Took it apart and small glass fuse was blown. Replaced it and plugged it in and hit power button and instant pop of the fuse. Already checked and 110 is coming from outlets that tv was plugged into. So my question is since 110 is coming from outlet and the fuse instant pops when I plug the tv in is it more than likely something else was blown on the power board of the tv?
 

Henry J Fate

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Assuming you have proper voltage at the outlet, it will be a problem with the TV and not the power source. Depending how old the TV is, you could open it up again and look for anything that appears to be burnt or over heated on the board. Fixing it would be another process. Most of the time these flat screens are throw aways.


Just a little curios...? Did the folks responsible for the improper wiring of the electrical outlet pay for the repairs to your converter ?
 

joeshannallie

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Thanks for the info. And no the damage was not paid for. It was a family member that unknowlingly used a 30 amp double pole breaker and thought breaker automatically had to have both legs connected. Already had breaker and did not think they really just needed a single pole. Simple mistake by not knowing. Everything is fine now but the tv. Probably just order new power board for tv and that should resolve the issue. Thanks again for your input.
 

Henry J Fate

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Well I guess the good thing about this is that no one was hurt. I have seen several different problems with outlets but have not bumped into this sort of mis-wiring yet. I thoroughly check out outlets before I plug in.


It may be a good idea to check out the prices of new flat screens. Unless you have something special in size,style or function, there are some pretty good deals out there in the 110 volt line for $100 or less. 


 

Rene T

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Like Henry said, those TV's are throw away's. You can compare the price of a new board versus buying a new TV and what happens after you replace the board the TV still doesn't work.
 

John From Detroit

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Repair is like 150/hr one hour minimum plus parts  My guess is a bridge rectifier but it could be somethign more serious.

#1 reason why I tell people to put in a 50 amp RV outlet not a 30.
 

HueyPilotVN

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Back when I was a kid, well in my early twenties, I took the home study course for electronics as a hobby.  It came with a heathkit color TV and different electronic tool like meters, scope, testers, etc.

Then a fellow that had a TV repair shop sold me all his parts inventory,

I spent way too much time fixing friends and family's TVs.  Always for free.

I finally gave away everything so that I could have more free time.

I did learn one lesson.  Back then a person that did TV repair for a living had to either be very good at diagnosing problems or not very honest about charging for repairs.

I totally agree that most consumer electronics now days are less expensive to replace than repair.
 

Back2PA

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John From Detroit said:
#1 reason why I tell people to put in a 50 amp RV outlet not a 30.

Agree. Cost is only a few bucks more, almost impossible to make a mistake, and the next owners of your home may have a 50 amp rig.
 
S

sightseers

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John From Detroit said:
#1 reason why I tell people to put in a 50 amp RV outlet not a 30.

??? ?  IMO.....The 50 amp RV plug would be way more likely to be incorrectly wired to supply 220 .... they have 4 wire connections.. two 120 lines (maybe the same phase, maybe not)  ..and one neutral.. and one ground.

A 30 amp only has 3 wires.. a 120 hot (black), a neutral (white), and a ground (green).
 

Back2PA

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sightseers said:
A 30 amp only has 3 wires.. a 120 hot (black), a neutral (white), and a ground (green).


The problem comes when someone runs two 120v circuits and a neutral with no ground to a 30A receptacle - the correct way to wire an old dryer plug, and it looks just like a 30A RV plug but will supply 240v to the RV. So with only 3 wires you get 240V - happens all the time.  The receptacle is actually wired correctly for a dryer, but not an RV.
 

Alaskansnowbirds

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sightseers said:
??? ?  IMO.....The 50 amp RV plug would be way more likely to be incorrectly wired to supply 220 ....

??? A 50 amp RV plug IS 220.  With the exception of the output of an inverter generator, I've never seen a 50 amp RV plug that wasn't 220.
 
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Back2PA said:
The problem comes when someone runs two 120v circuits and a neutral with no ground to a 30A receptacle - the correct way to wire an old dryer plug, and it looks just like a 30A RV plug but will supply 240v to the RV. So with only 3 wires you get 240V - happens all the time.  The receptacle is actually wired correctly for a dryer, but not an RV.

but if two of the 3 wires on a 30 amp plug are hot...the breaker should trip instantly,  because one of those hots would be connected directly to either the neutral bus-bar (which is also bonded to ground) or the ground.

220 Dryer plugs should have 4 wires...and because of it being a wet appliance..  one of them should defiantly be a ground.
 
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Alaskansnowbirds said:
??? A 50 amp RV plug IS 220.  With the exception of the output of an inverter generator, I've never seen a 50 amp RV plug that wasn't 220.

Since there aren't any 220 circuits in most RV's..  the 50 amp plug could also just have two 50 amp 120 circuits of the same phase.
 

HueyPilotVN

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I just wired up a 30 amp dryer outlet the other day for a dryer in the garage for Renae's daughter Kelly and it only uses 3 wires.  The ground, (bare copper), is not connected.  The two 120 hot wires are on both sides and the neutral is in the middle.
 
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sightseers

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HueyPilotVN said:
I just wired up a 30 amp dryer outlet the other day for a dryer in the garage for Renae's daughter Kelly and it only uses 3 wires.  The ground, (bare copper), is not connected.  The two 120 hot wires are on both sides and the neutral is in the middle.
So you have a wet location 220 volt appliance ...that is not grounded....

it don't sound right to me.
 

jrclen

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I'm a retired master electrician. A $10 multi meter and a quick test of the receptacle outlet will show the volts before connecting the RV.
 

HueyPilotVN

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I just took a picture of the instructions for the 30 amp NEMA Dryer outlet.  The 50 amp NEMA does use the 4 wires including the bare ground.
 

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sightseers

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jrclen said:
I'm a retired master electrician. A $10 multi meter and a quick test of the receptacle outlet will show the volts before connecting the RV.

So as a master electrician... don't you think the neutral and ground wires should be joined on a 3 wire 220 dryer plug
like this ?
 

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Spridle

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sightseers said:
Since there aren't any 220 circuits in most RV's..  the 50 amp plug could also just have two 50 amp 120 circuits of the same phase.
This is a very dangerous assumption so please don't do that.

A NEMA 14-50R receptacle is used for 50 amp RVs. It is a 120/250 device with a "balanced neutral". If this device was intentionally wired without using a two pole breaker with common trip handle there is a strong possibility that the neutral in the extension cord and the home run neutral will have far in excess of 50 amps creating an substantial hazard.
The NEMA standards clearly state this as well as the code. Only use a two pole breaker as designed or risk consequences when installing a 50 amp 14-50R. Insurance adjusters do hire qualified electricians for expert witness testimony.
Always look up the NEMA configuration of your device and follow what it says. Its not open to interpretation.
Sorry if this sounds blunt, but this is very dangerous and had to speak up.

FYI the old 3 pole dryer outlets and range outlets used the neutral to bond the frame. Newer homes use a 4 pole device because bonding the frame with a neutral could be dangerous in certain scenarios.
 
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sightseers

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Spridle said:
FYI the old 3 pole dryer outlets and range outlets used the neutral to bond the frame. Newer homes use a 4 pole device because bonding the frame with a neutral could be dangerous in certain scenarios.
yes it is dangerous..especially in wet locations, (like a washer/dryer).  if the neutral should open...it could make that rubber footed metal dryer chassis.. completely charged with 220 volts.

and it's looking to go to ground through the next person that puts a hand on it.

It used to happen in houses with aluminum wiring.  I had one customer with an electric stove that would shock you when you turned it on...it was a broken neutral on a 3 wire 220 stove.
 
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