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Working on a vintage fan - whole thing is electrified when plugged in. What am I doing wrong?

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BillGunn

Aug 16, 2016
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I'm working on a vintage METAL box fan from the 1950's that has a 3 speed variable switch. The switch has three prongs with wires that lead down to a copper coil. This is held together with a bracket that then itself fits into a metal box that hides everything.

Upon taking apart the fan to clean it up I did three things - I disassembled the motor and cleaned it (Which I did correctly), I replaced the power cord, and I accidentally pulled a wire off of the switch's prong which required me to disassemble it and attempt to reattach the wire. I manage to reattach it. I took the fan outside and plugged it up with the switch box lying separately on the ground and the fan seemed to function fine, I even touched the actual fan itself (not the switch. Which means the issue is in switch, not the motor). So, thinking I had successfully fixed it, I brought it in, reassembled it (I.E. reattached the switch assembly to the fan housing), and gut instinct told me to take a voltage detector to the frame before touching it - that voltage detector went off within a foot radius of it. This was with the actual fan turned off.

I took it back apart, and examined everything. No wires had come loose inside of the metal box. The switch assembly bracket was touching the side of the box, though.

My thoughts are that I wired the power cord on in reverse, seeing as the fan housing should act as a ground (and thus I have hot electricity running through it in reverse), but I have no idea. My experience dealing with electricity is a big fat 0%. I could not even tell you the difference between an AC current and a DC current, aside from the fact one comes from a wall and the other a battery. Although I do want to repair this thing myself, because 1: I have no money to hire an electrician. and 2: I wish to learn how to tinker with things like this.

This whole thing seems incredibly dangerous even if it was functioning perfectly. It appears that if somebody were to knock it off of a shelf hard enough and knock a connection loose, it would probably electrocute the crap out of you, even on a good day. So any tips to make it safer (as I intend to use this thing) would be great!

Also, could somebody explain to me how this switch works, and what exactly the coil does?
 

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dorke

Jun 20, 2015
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Welcome to EP.
The best advise I can give you is to take it to a proper electrician for fixing.
This isn't something a person with "big fat 0% experience" shouldn't handle ,it can kill you!!!
 

BillGunn

Aug 16, 2016
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Welcome to EP.
The best advise I can give you is to take it to a proper electrician for fixing.
This isn't something a person with "big fat 0% experience" shouldn't handle ,it can kill you!!!

Which is why I come here to discuss and learn. I've also taken many precautions and have been very careful.

It is a switch, and two wires leading to a motor, this is the exact kind of project that somebody with little experience should learn on. With proper precautions (which I do take), and patience, this can safely be done with help.

EDIT: Also, Dorke, I have called around to several certified electricians, and even hung and asked around at places like Best Buy, Radio Shack, and Anthony's (a repair shop) and they all just gave me a big shrug of the shoulder and said they didn't, nor did they know anybody, who worked on them. This is a project that is truly a Do-It-Yourself (with the help of the internet) kind of job. Make no mistake - I am also concerned about my lack of experience, and I will do my best not do anything that will get me killed. I will NOT do anything that I feel is truly beyond my ability.
 
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Minder

Apr 24, 2015
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It should not make any difference which way you connect the power cord except the ground wire should have continuity to the metal case and any metallic part that can be touched.
Although technically the switch should be in the live conductor.
The fan housing should be at ground, but not considered a conductor.
As long as the ground pin on your cord has continuity to all the parts mentioned, it should be safe regardless of how bad a design it is.
If a ground does exist it will then blow a fuse, (or should do)!.
M.
 

BillGunn

Aug 16, 2016
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It should not make any difference which way you connect the power cord except the ground wire should have continuity to the metal case and any metallic part that can be touched.
Although technically the switch should be in the live conductor.
The fan housing should be at ground, but not considered a conductor.
As long as the ground pin on your cord has continuity to all the parts mentioned, it should be safe regardless of how bad a design it is.
If a ground does exist it will then blow a fuse, (or should do)!.
M.

I have wired this fan in the exact manner that it was when I found it. The cord I have is a two prong and lacks a ground. Should I find a cord with a ground pin, and then connect that to the metal case?
 

Minder

Apr 24, 2015
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It probably pre-dates the requirement for 2 wire appliances to be double insulated, and get away without using a ground.
You should use a 3 conductor cord, and ground to the metalic case, but don't be surprised if it blows a fuse.
It sounds as though regardless of how the original was wired and whether you erred at all, it should be grounded.
M.
 

BillGunn

Aug 16, 2016
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It probably pre-dates the requirement for 2 wire appliances to be double insulated, and get away without using a ground.
You should use a 3 conductor cord, and ground to the metalic case, but don't be surprised if it blows a fuse.
It sounds as though regardless of how the original was wired and whether you erred at all, it should be grounded.
M.

Why would it blow a fuse if it is grounded? I'm curious.

Also, do you believe it would be possible to modernize this thing? How would one go about doing that?

Thanks for your time, sir.
 

Minder

Apr 24, 2015
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If there is a ground fault on it where you would receive a shock, the ground conductor avoids this, but if there is voltage present on the case the current (short circuit) will flow to ground instead of through you!.
Usually blowing a fuse, if the leakage current is high enough.
Modernizing it is fitting a 3 core cable.
M.
 

BillGunn

Aug 16, 2016
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If there is a ground fault on it where you would receive a shock, the ground conductor avoids this, but if there is voltage present on the case the current (short circuit) will flow to ground instead of through you!.
Usually blowing a fuse, if the leakage current is high enough.
Modernizing it is fitting a 3 core cable.
M.

Alright! This is the kind of information I was looking for. Thank you very much.

If everything is wired correctly, why would the metal case be conducting, though? I looked it over, and there are no wild loose connections. I cannot see any source for this. Is it normal for old appliances like this to have a current going through it?

My brother actually reached down and grabbed it while it was running (despite several warnings from me) , and he received no electric shock. So the current may not be sufficient enough to shock a person. (Although I am not going to risk it.)

I actually just purchased a book used by military personnel how to quickly learn the basics of electrical wiring, so hopefully I'll come back this with a bit more knowledge on the subject.
 

Minder

Apr 24, 2015
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To check insulation you need a special meter called a megger, this tests the actual insulation by applying a high voltage and recording the leakage resistance, if any.
If he did not receive a shock it could be he was sufficiently isolated from earth ground or the leakage is at a small level.
But with an old appliance like that it is best to play safe and earth ground it.
M.
.
 

BillGunn

Aug 16, 2016
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To check insulation you need a special meter called a megger, this tests the actual insulation by applying a high voltage and recording the leakage resistance, if any.
If he did not receive a shock it could be he was sufficiently isolated from earth ground or the leakage is at a small level.
But with an old appliance like that it is best to play safe and earth ground it.
M.
.

Do you believe it would be possible to better insulate the switch housing in order to prevent this leakage? It is made of metal.

I had this idea of spraying the inside with a material like liquid rubber, or truck bed liner.
 

BillGunn

Aug 16, 2016
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To check insulation you need a special meter called a megger, this tests the actual insulation by applying a high voltage and recording the leakage resistance, if any.
If he did not receive a shock it could be he was sufficiently isolated from earth ground or the leakage is at a small level.
But with an old appliance like that it is best to play safe and earth ground it.
M.
.

Also, when I first posted this, the current was traveling through the fan when the switch was "Off", and then I flipped the ?polarity? of the cord around (Just swapped the wires) and after that the current flowed through it when it was "On". Why would this be?

(I did this on a wooden elevated porch, wearing rubber boots, and I would unplug it for each time I changed the switch.)
 

Bluejets

Oct 5, 2014
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It is more than obvious that you have no idea about the dangers involved here or indeed how "non-contact voltage detectors" work. As has been said previously , take it to a qualified electrician, not radio shack, not local diy handy man who al shrug at any request for a megger test as it is obvious they are not qualified to comment anyhow. Do yourself and everyone around you and leave it to those who know. You ask what you are doing wrong, there is your answer.
 

BillGunn

Aug 16, 2016
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It is more than obvious that you have no idea about the dangers involved here or indeed how "non-contact voltage detectors" work. As has been said previously , take it to a qualified electrician, not radio shack, not local diy handy man who al shrug at any request for a megger test as it is obvious they are not qualified to comment anyhow. Do yourself and everyone around you and leave it to those who know. You ask what you are doing wrong, there is your answer.


"take it to a qualified electrician, not radio shack, not local diy handy man who al shrug at any request for a megger test..."

I have not found a single electrician willing to work on it, or even look at it. Was that not obvious in my post?

"no idea about the dangers involved here..."

I do know the dangers involved. I have personally felt the kick of a 220v outlet pulsing through my body before, and I have a permanent heart arrhythmia that will most likely kill me to show for it. What about you?

You seem to have this image of an idiot who is going at this willy nilly. I will not do anything beyond my ability. Am I ignorant about the subject? Yes. Which is precisely why I am trying to grasp it. I haven't made a single move on this fan since I opened this discussion, and I will not until I speak with more people and am sure of what is going on. I safely made an observation, and I am sharing this observation. If I had wired this fan myself, I wouldn't be attempting this, but the fan is wired as it was new. This is why I am trying to understand why it is doing what it is doing. If anything, at this point I am just curious.

"You ask what you are doing wrong, that is your answer."

You know, this fan was in functioning condition when I pulled it out. Majority of people, most likely even you, would have made physical contact with it without a second thought. I had the foresight to insulate it, insulate myself, and plug it into a fused outlet and ensure that there were no currents running through the metal chassis before touching it. I caught it before a horrible accident could have happened.

So, I am terribly sorry, but I would have to kindly disagree with you.
 

Bluejets

Oct 5, 2014
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As with Minder and several others here, I am a qualified electrician and as such one gets to know those unqualified sometimes merely by their attitude to electrics.
You have already stated initially you believed the item to be dangerous and yet you freely admit the both you and your brother have had a "touch" of the device in question but are now curious as to why you were not zapped.

You also freely admit to have had a touch-up at some stage from playing with things you don't know anything about but still you do not learn.

I believe no one here will comment any further on this other than to say, seek professional help.
 

BillGunn

Aug 16, 2016
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As with Minder and several others here, I am a qualified electrician and as such one gets to know those unqualified sometimes merely by their attitude to electrics.
You have already stated initially you believed the item to be dangerous and yet you freely admit the both you and your brother have had a "touch" of the device in question but are now curious as to why you were not zapped.
I believe no one here will comment any further on this other than to say, seek professional help.

I did not touch this device. Not once. I have stated this. And as for my brother, I warned him over and over. He insisted calling me "paranoid" and "worried", and then did it. Even after he did not die from electric shock I still did not lay my hand on any part of the fan when it had live electricity going to it.

"And as such one gets to know those unqualified by their attitude to electrics"

I have had nothing but questions and curiosity. As I stated, over, and over, and over, I will not do anything with this fan until I am confident in doing it. Likely, I will not do anything with it until I can find somebody to supervise me. I came to this forum to understand, or try to solve, what is happening. Admittedly this is not as clear in this, as I have asked for solutions.

I know this much

1: The source of the current in the frame must be found and fixed.

2: The casing for the switch must be insulated properly.

3: (Thanks to Minder), the fan must be grounded.

4: I have also found the wires inside of it to be quite corroded, and a few in need of replacement. I know a corroded wire provides greater resistance, increasing heat, and with the aged nature of the wires, an increased likelihood of fire. I believe a few connections need to be re-soldered as well, as they are quite weak and could come loose.

I inspected the motor and found very little corrosion. It runs strong, and quietly.

You have do not know me, because if you knew my nature you would know how careful I am when treading into territory that I do not understand. I insulated myself, Rubber gloves, ear muffs, goggles, thick rubber work gloves, and a pair of boots. The fan was sat on a wooden box that sat on 4 rubber feet.

This thread was more or less a way to try and understand the workings of the fan from qualified people.

I figured this fan, with it's relatively simple nature, would be a good first step into understanding how these electric things work, and repairing it (if possible) would give new life to a fan that has been in my family since 51'.

But I guess I won't. I'll assemble it, and put it on my shelf and not touch it again. Thanks for the advice you did give. I'm not angry, just a bit disappointed.
 
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