Love becomes Electric – Electrical Safety and your sewing machine

*Note:  The photo above is of a mis-assembled power connector.  This is an example of what not to do, or Love becoming Electric – which is the topic of this conversation today.

Today, I want to talk about the electrical connections in your vintage machines.  In particular, the topic will be when you’re using the machine and you feel a tingle, or a light shock, or buzzing sensation.

A couple of months ago, someone brought a website to my attention.  The site positions itself and the owner as an expert in the field of vintage sewing machines, but they’ve made a statement that I have some concerns about as it pertains to this topic.  I want to clear up some misconceptions about electricity and how it pertains to vintage sewing machines.

I’m paraphrasing how the site worded their statements, but I’m staying true to what was said.

Please note:  I don’t want to start a war, I want people to be safe. This is why I’m not linking to the site, or quoting it.

The site mentions a few causes of the shock.  Among them:
  • the wires in the foot controller could be wired improperly.
  • the non-polarized cord could be plugged in wrong, and that turning it upside down can alleviate the issue.
I have no doubt that this person is good with the machines, but electrically, the advice is unsound.
Dangerously unsound.

First, a little bit of electrical theory.

Back in roughly the 30’s up until about 1962, in North America, new construction in houses could be done with unearthed sockets or what we would refer to typically as a “non-polarized plug”.  This meant that the cord could be plugged into the wall in either direction, and it would work just fine.  After this standard came in, devices continued to be shipped with  non-polarized cords.  In fact, several of the new and fairly new computer and electronic devices in our house have non-polarized plugs.  Frankly, if it was possible to get an electrical shock from a device because it was plugged in backward, these plugs would have been banned by now, not grandfathered by the building code.  There would be no non-polarized plugs on the ends of any of our devices.

After all, some countries in North America have gone so far as to ban Kinder Eggs.

Dangerous heart stopping, electrocution causing plugs would be banned for sure.

The cords were not polarized in the past, because it was not the “standard”.

The fact is, with non-electronically sensitive devices, like a vintage sewing machine –  it truly does not matter which way you plug into an alternating current (AC) power receptacle.

With AC power, there is no constant positive and negative, hence no right or wrong way to plug the cord in.

Lincoln Electric, the makers of welders, says this about electrical polarity:

Alternating current (AC) flows half the time in one direction and half the time in the other, changing its polarity 120 times per second with 60-hertz current.

You don’t get to choose which way it flows by plugging in one way or the other.

This is also the reason a sewing machine motor doesn’t run in reverse if plugged in one way or the other, or if we switch the wires at the machine side.

The other thing to note about AC power, is that it requires a very small amount of it to disrupt the human heart. Less than 1 amp. Your wall plug is likely capable of supplying between 15 and 20 of those amps.

Typically, with 120volt service (In North America, this is what your wall plug is using, but not your dryer), you will be “thrown clear” in a potential electrocution situation, but it’s still not good for your heart, muscles, tissues, or peace of mind.

And it hurts.

A lot.

Yes, unfortunately I speak from experience.

So let’s look at that.  How did I shock myself?  I thought I’d unplugged a machine, when in fact, I did something I’d never done previously, and not since, for the reason you’re about to read:

Instead of unplugging the machine from the wall, for some reason – I’ll claim it was lack of sleep – I unplugged from the machine and began working on the plug that had an open circuit (loose wires).  It took me almost a minute, but eventually the inevitable happened.  I shorted the 2 poles of the connector with my fingers.  Luckily, as mentioned above, with 120V, typically the spasm will cause you to unclench, and I dropped the connector.    As it was, when it initially happened, I couldn’t breathe for a few seconds, I curled up on the floor for “a bit” and my upper body, especially my chest, ached for days afterward.  This did NOT trip the breaker, and typically won’t.

That scenario went straight past buzz to pain, but it’s all varying degrees of the same thing.  When there’s a short in your machine, it’s being “shocked” with power the same way I was above.  When you touch the machine while it’s being shocked, you become a part of the circuit, and get shocked, or “buzzed” too.

This is not to be played with. I don’t want to sound all doom and gloom, but it’s dangerous to believe that which way you plug it in will make the difference. It would likely be mandatory to change a plug out to a polarized one if simply plugging it in “wrong” could cause electrocution and fires.

Now let’s look at the statements.

1.  the foot controller being wired backwards, or incorrectly.

The Singer bakelite foot pedal can’t be wired in reverse.

For example, you will notice that there is no mention of being careful which wire to put to which connector in either of these articles:
http://blog.sew-classic.com/2010/01/…g-machine.aspx
http://blog.sew-classic.com/2009/11/…r-control.aspx

For the same reason as mentioned above – AC current doesn’t have constant polarity. All a foot pedal does is break one of the power wires going to the motor and add in some sort of resistance to allow variability of speed.

2. the electrical buzz goes away when I reverse the cable in the plug on the wall

I suspect the reason the problem went away when you unplugged and plugged it in the other way is that the wires that were shorting together were nudged apart by the movement, and are no longer shorting. This is a temporary condition, the cord or the wiring inside MUST be addressed for safety.

Typically the shock is caused by a wire that’s bare (rubbed so the wire is showing, or the insulation is simply missing) or loose and touching somewhere it shouldn’t.  When this happens, the power follows the shortest route to “ground”.  That’s through the body of the machine, and then through you.

So where could these bare wires be?

There are three main places where wiring are most likely to be compromised on a vintage sewing machine.

Working our way from least expensive to most:

  • This wire -could- be in the pedal, but if it is, it’s likely to be the cord that’s the issue – If the cord set has a broken wire, it’s the easiest repair on the planet. Anyone can do it. It’s not a delicate operation that requires any special skills. It’s a simple job and the cord is held on by 2 screws.  If you can manage a screwdriver, and take it “slowly” the first time, you can do this.  The hardest part is routing the new cord so it sits flat.  This is typically the least likely place for the issue to be.  Here’s why: The last machine I serviced for a cord / pedal issue, the symptom was “machine went berserk, I had to unplug it to stop it” Most often, a short between the machine and the pedal manifests this way. Yours could be the exception though, so it warrants a look.
    • I suppose it’s theoretically possible to have the pedal be the issue if the cushions on the bottom of the pedal were missing AND the cushion screws were sticking out and touching metal or water AND there was something wrong inside the pedal causing that screw to be touching part of the mechanism that’s carrying power. I really doubt that perfect storm would ever occur though.
  • A heavily damaged connector.  There’s bakelite between those connectors for a reason.  With featherweights, for instance, the male connectors often get broken putting the machine into the case.  I’ve had 15s and such with broken connectors too, and I can only assume that they were bashed into a wall or a table at one point.  I often wonder how the table or wall fared in that battle.  The female connectors are broken mostly from being too rough connecting and disconnecting from the machine.
  • The wiring going to the motor or the light – the thumb nuts where you connect the cord to the machine – the ones that you see when you turn the machine over to oil / grease the bottom – could be hiding some bad wiring, or the rest of the wiring from the motor and light to the connector could be damaged.  This is usually the most likely place, because usually the bare wire has got to be “touching” the item it’s using for ground (in this case, the body of the machine), which is what’s giving you the “buzz”.  It’s possible too that the connectors are loose enough that the wires have slipped from where they’re supposed to be and touching each other.  Simply tightening them is not enough, you need to put the wires back where they belong.

With most vintage machines, none of these scenarios is difficult to fix.  As with any electrical repair though, if you’re not sure of your abilities, it’s better to have someone qualified look at it.  I would have no concerns whatsoever though in encouraging someone to change a foot control cord using Jenny’s instructions above.

So, what if you decide not to fix it, and put it away for a bit?  I would suggest that if this machine goes on the shelf, put a note with it, saying that it needs some electrical work. Better still if you know what it is, mention that too, or at least that it’s a shocking little thing. This way, down the road, if the machine goes to someone else without being fixed, they don’t have to relearn what you have here today.

 One last point:

Singer and other manufacturers over the years have all recommended unplugging machines when not in use.  This is largely to prevent fire risk.  The carbon pile / bakelite button foot controllers, especially when improperly adjusted, can generate significant heat even when not being used, and potentially start a fire.

Many people think that by flipping the “switch” on the machine, they’ve cut the power off from it.  Especially with vintage machines, this is often not true.  A lot of the time, all that’s happened is the light turned off.  Go ahead, give it a try.  Press the pedal with the switch turned off.  You may be surprised.

37 thoughts on “Love becomes Electric – Electrical Safety and your sewing machine”

  1. Excellent article and I would like to add a few things for clarification. In North America there are normally 2 black and one white wire plus a ground going into a house. The white wire is the neutral and is bonded to the ground at the main panel box only. The two black wires each have a potential of 120 volts to the neutral but between them the potential is 240 volts. At the wall outlet there is a ground, a neutral and a hot. The neutral is the wider slot and the hot is the narrow slot and the round one is the ground. The purpose of the polarized plug is to ensure the plug is put in one way only and the hot line stops at the switch. The rest of the appliance has no power. Also if its a light only the centre pin is hot when the switch is turned on. If any wires in the appliance contacts the frame after the switch the appliance will not become a shock hazard. When I replace a plug on anything I always make sure the narrow pin on the plug is the one that goes to the switch. A ground fault interrupter measures the flow of electricity in the hot line and neutral and if there is a difference shuts down. Ie: hot through you to ground. If the flow of electricity is hot through you to neutral nothing happens, you still get a shock. If there is the slightest flow to ground also then it will shut down. If the circuit you are using has no gfci you can purchase one on a power bar or short extension cord. When rewiring a vintage machine or replacing the plug I would run the hot to the foot control so the rest of the machine is not hot when it is not running. Wiring in other parts of the world I am not familiar with. Sorry this is so long but I hope it helps.

    1. All very good points. I usually don’t go into that much detail about power because it’s somewhat out of scope of the machines but I see absolutely nothing wrong with what you’ve stated above. 🙂

  2. Hi, I found this interesting topic meanwhile I was finfing out about theproblem of my mother’s singer sewing machine. I thonk it can be a 201, no way to know, around 1963. It stopped working, ot looked like a foot problem and we went to a shop where repair sewing machines. The old guy tested in front of me and it worked fine. Said that there was no problem rxcept maybe the gear, so he should see the entire machine.
    As the cord has a little damage, I decided to cut off that part and assamble the 3 plug thing again. Then the machine started running and the only way to stop it was unplugging from the wall again. I tried 3 times, all the same. I thought that maybe I had reverted the wires so started all over again, but this time the machine dfidn’t work.
    As far I could see the gear was not the problem, so I don’t want to come back to the workshop. Could you give me some idea?
    (I apologize for my poor English)

    1. Hi Laura,

      Since the cord worked before you cut it and doesn’t any longer, I’m thinking that you have some wires switched. I looked up where you are – Argentina? Does that mean you have 220V power? If yes, then the wiring diagram I posted a link to for Youle in the response below won’t work for you – perhaps there’s an electrician who can help you? For vintage sewing machine power problems, they’re simple electrical issues – not electronically sensitive issues – any electrician or small appliance repair person should be able to wire it for you.

      In general though, a racing machine indicates that the foot control wire has been bypassed or something has otherwise shorted. A non-working controller usually indicates that there’s an open circuit – either by a connection that was not tightly made, a broken wire or a mistake in wiring.

  3. Hi 🙂 I just dropped into your blog while looking for information about how to be safe with the electrics of my sewing machine. First of all, sorry for my mistakes, english is not my mother tongue.

    I bought a vintage sewing machine a few weeks ago. I rapidly noticed that I was receiving very small “buzz” while touching some parts of the machine. I immediately stopped using it (I’m pretty much scared of electrical accidents).

    I noticed the wire from the plug to the machine was damaged in some places.

    I replaced the wire with a new one, which has an earth, and connected the earth wire to the body of the machine, as adviced by a friend (he doesn’t know a lot about electricity, just the basics).

    I’d like to know wether this is a good thing or not ? Can I consider myself safe with this machine now ? I used it again and got no buzz again. Also, I’m still not totally sure wether I was buzzed by the machine or that was static electricity (I’m very sensitive to static electricity, particularly when the weather is dry).

    1. Hi Youle,

      There’s nothing wrong with your English!

      You’re wise to be concerned about electrical problems – they’re pretty much the only part of a sewing machine that can kill you.

      I’ve seen several people talk about / ask about earthing a vintage sewing machine and interestingly all of them have been from the UK or Europe somewhere. I’d hesitate to advise you on this because I can’t see what you’re doing. The best thing I can suggest is talking to someone who does have training in electrical work – that may be an electrician or even a small appliance repair person. If you’re lucky, maybe there’s a family friend in one of those fields who can advise you?

      Either way, I will always advocate erring on the side of caution. If it was a static discharge – you’ve done nothing bad by replacing the cord – I make sure all cords that show signs of damage are replaced.

      1. Hi again !
        Thanks for your answer. After I continued looking for information. Normally, equipments without an earth, are “double-isolated”, and it is forbidden to earth them. What I’m not sure about, is wether vintage sewing machine are double-isolated or not. And you’re right, I’m from Europe (France).

        Anyway, I think I’ve done something wrong because now, when I start sewing and the light of the machine is on, it is getting “off” when I push on the foot control. I have to redo the work.

        I will try to find someone that knows more about electricity, your advice is a good one, I didn’t have the idea of asking a repair shop owner, will do that as soon as possible.

        1. From what I recall – a vintage machine is not likely to be double isolated but check with someone who’s qualified for code in your area. Most double insulated appliances I see have a plastic shell – thus disqualifying most vintage sewing machines. I think you will find that the machine predates the code talking about double isolation. If I knew where my electrical code book was, I’d go look it up. Alas…

          I’m not sure which machine you’re working on but usually what causes the light to go off when you press the pedal is that you reversed 2 of the wires – the one that connects to the pedal and the one for the light. I have linked to a 120V version of the proper wiring for a featherweight or similar Singer machine (the principle is the same for most vintage machines but may be arranged differently) but I don’t have a link for a 220V version so I could only really make very basic suggestions. The 120V version is at the bottom of this page: http://ismacs.net/singer_sewing_machine_company/singer_featherweight_sewing_machine.html

          In that diagram – your light should be on 1 and 3. My guess is that your light is on the European 220V equivalent of 2 and either 1 or 3. I think the last time I accidentally swapped 2 wires, it was 2 and 3 I switched and 1 was correct. This is the easiest mistake to make because of the underwriter’s knot. If you trace it wrong, you can swap the wires very easily.

  4. What is going on with the reversing plug “fixes” the shock scenario:

    There is some kind of connection between the wiring and the metal body of the machine. It could be a direct short (Yes, a short between a hot lead (or a neutral for that matter) and an ungrounded cabinet will NOT pop a breaker), or it could be “leaky” wire insulation, carbon build up somewhere, or even in the motor. Point is, its there.

    Reversing the plug may “fix” this as this changes the so-called “polarity” of the circuit – the short/leaky connection is reversed to be closer to ground potential so the user no-longer feels it. In fact, some old equipment such as AC/DC tube radios often had one side of the AC line connected directly to the chassis ON PURPOSE. If the radio shocked you, you reversed the plug!

    It is, of course, a VERY good idea to find and fix this type of situation before someone gets hurt…

  5. Hello! I have a question regarding an old-ish overlocker I have. I touched the foot while using it one day and it buzzed me, just a little. My husband came and had a wee look and found that the earth wire in the plug was loose, would that explain it?

      1. I have been too chicken to try -_-‘ I will do so and see. He said the whole inside of the machine looked like it had been spit shined, it was that clean. So I’m hoping that’s all!!

  6. Hi there! So I have been googling and found my way here, and there’s some good info, but I have a specific and very concerning issue, I’m hoping maybe your knowledge can solve. Yesterday we found a vintage white dressmaster rotary, the 127 model. I tested it at the thrift store, and it worked like a charm, so we brought it home. Well today, I went to plug it in, and the power in that part of the house turned off! I assumed I tripped the breaker, but resetting it didn’t seem to help. So, that’s another issue I’ll deal with soon. But meanwhile, I’ve been continuing to try to get the machine running. I have been plugging it into a power strip, which then will trip every time, along with sparks, and now even what looks like the tips of the prongs on the power cable slightly melting. Based on what I’m reading here, I assume there is some cross wiring happening, but I don’t know where! It may have been a bad idea, but I unplugged the 3 hole female end of the connector for the pedal and power cord from the motor and plugged in the power cord, hoping to narrow down where it could be, and had the same results. If you know of a way to narrow down where the fault may be, or the next step to logically take, I would appreciate the help very much. We are not well off, and I’d like to be able to fix it myself, for as little as possible, but of course, I understand if that’s not possible. Sorry this was so long!! Thanks!
    Stephan

    1. Hi Stephan, first off – please don’t plug that machine in again until you get the electrical sorted. It’s quite frankly dangerous at this point.

      As in heart stopping electrocution / fire causing dangerous.

      Somewhere, you have a dead short.

      Essentially what’s happening is that the machine either with everything else on the circuit or on its own (most likely) is overloading the circuit causing the breaker to trip. A vintage domestic sewing machine shouldn’t draw more than around an amp – or between 1/10 and 1/20th what the average breaker can handle. Were you unable to get that breaker to reset, or just hadn’t gotten to it yet when you posted this? Either way, continuing to test this machine despite sparks and to the point of parts failure (melting plugs) will undoubtedly cause even more damage to the machine and possibly you and your home.

      You need to first evaluate all of the wiring to see if it looks like it’s broken, melted, torn, insulation missing, etc. This includes any internal wiring if applicable for the light.

      Next, you need to make sure any faults are corrected. Since money’s an issue, I suggest either:

      1. Putting it aside until you can afford to have someone look at it if your electrical skills are not up to the task* – and please be very honest in this area. As you’ve already seen – this is very dangerous territory.

      *While I do normally actively promote self-help as far as most sewing machine maintenance, I cannot in good conscience advise you to take this on yourself without being able to personally evaluate your electrical skill level.

      It takes about 0.10amps to stop a human heart – or 1/10th of an amp which is roughly 1/100th to 1/200th what that breaker is currently trying to supply to that machine and there’s a good chance the body of that machine is live.

      or 2. See if you can barter with an electrician friend for some sort of service or product in your possession.

      Please put your safety first. And please let me know you’re still out there and OK after messing with the electrical on this machine!

      1. Thank you for your concern. I had stopped by the time I commented initially, and at that I had just been stubborn in continuing as long as I had, it’s just that it worked perfectly at the thrift store! 🙁 anyway, in answer to your questions: the circuit did not come back on, regardless of resets, and still today it is not working. There was already a bad plug that I assume is on that same circuit, so I believe the shorted machine just pushed it over the edge, which is really unfortunate considering it’s what the fridge would normally be plugged into (using a power strip with a long cord attached to another plug for the fridge currently…). Once the circuit broke, I tried conneting the sewing machine to a power strip, which would then trip the strip itself every time. And again, this is when I noticed the slight melting on the tips of the machine’s plug. And that’s when I opened communication here. So don’t worry, I won’t be carrying on with plugging it in.
        And yes, what I was able to notice was that there are cracks in the insulation of the cords of both the power and the pedal, and in attempting to solve it covered the power cord with electrical tape, to no avail. Do you think such a a significant issue could just be the result of the cracked insulation, and if covering the pedal cord with electrical tape would possibly solve it? At this point I’m feeling like I may have to replace both cords, which I’ve never done, but I have soldered before, and am competent, though clearly a bit too daring.
        Thanks again for all the info.

        1. I’d be inclined to say something got disrupted between the store and home. It could be as simple as a wire that slipped loose from somewhere and is shorting or it could be it was about to fail but they were lucky at the shop to not have what you had happen.

          Is the breaker one of the toggles? Does it stay in the on position or does it reset only half way? Half way usually indicates that the short problem is still there. All the way but no power may mean you need a new breaker. I’ve had both situations here. If I recall, the burned out breaker was courtesy of an outdoor plug that shorted in the winter. The good news is that the breaker has done its job in all cases. It stopped a massive draw and the fire that can go with it.

          A fridge draws a lot of power on its own. Mine says that it uses 7.9A. I wouldn’t usually try to test much equipment at all on the same circuit as the fridge.

          Cracked insulation could potentially be enough if it’s cracked enough to be allowing the wire to arc to something else. I think it’s more likely to be 2 wires rubbing together somewhere, but to the body or to the motor is also possible. It could also be a fault in the light or in the motor itself. We often go after the wiring first because it’s most visible and most likely to suffer damage. Keep in mind many of the above scenarios can also “charge” the body of the machine providing a route to ground through your body.

          Typically, if you put electrical tape on top of a problem wire, you’re just hiding the problem from view – so no, I wouldn’t think that will resolve anything properly. You need to go over the machine with a fine tooth comb and find where the short is and resolve it properly. Wire, shrink tube and even a couple of plugs is very cheap insurance vs. a fire insurance claim or a death due to fire or electrocution.

          One thing to keep in mind: A kludge looks like a kludge. A proper fix never looks like a kludge. Electrical tape on top of a set of misbehaving wires is always a kludge.

          1. Thanks so much for all of this! Ok, so to narrow it down, there’s literally only three wires that I can see, one connecting power to the motor, one connecting the pedal, both of which share the same 3 prong female harness to connect to the male prongs on the motor, and one coming directly out of the motor to the light. There’s no way to detach the light that I can see so it may be difficult to rule that out. But meanwhile, as per my original post, when I unplugged the harness connecting the power and pedal to the motor, therefor leaving the female end bare, I had the same symptoms of tripping the power strip. Is it safe to therefor assume that the issue lies in these 2 cables, or is the tripping an inevitability simply because they were detached from the motor, and therefor the power had nowhere to go?
            As far as the circuit breaker, I still haven’t isolated exactly which of them it is, but none of them are stuck halfway, nor did resetting any of them help, therefor if one of them is bad as you’ve said, I don’t even know which one! Haha all I know is the fridge went out when that particular plug did, therefor they are connected somehow, assuredly by the circuit breaker. Anyway, I may have to get an electrician on that regardless…
            You are a wealth of knowledge, and I appreciate you sharing and attempting to help with this bizarre issue. 🙂

            1. Where are you at with this now?

              By your description – you’re dealing with 3 SETS of wires – hot and neutral to the motor, hot and neutral to the light and more than likely a power and return to the pedal. These will combine – usually at some sort of junction – to lead all of the hot wires to the single hot wire leading to the wall and all of the neutral wires to the single neutral leading to the wall. How this is set up on this particular machine, I couldn’t say. I can’t in good conscience advise you on it because I can’t see it. It may be as it was from the factory or it may have been altered since. It’s clearly not operating correctly though and is dangerous as it sits. I will say these few things though:

              1. You can’t treat a set of wires the same as a single wire. The logic will never work.
              2. No, an open circuit (“power had nowhere to go”) should not cause a breaker to trip. An open circuit is basically the same as nothing being plugged in – no circuit is being made so the “tap” hasn’t been turned on and nothing is flowing.
              3. A short will trip a breaker.

              I really think if you’re going to get an electrician in that it would be a good idea to have him/her look at the machine for 2 reasons – it started the problem and may help lead your electrician to the full scope of the problem and he/she will have a solid understanding of electrical theory and its role in the problems you’re experiencing with the machine.

              1. Hey! First and foremost I want to thank you again for all your knowledge and genuine concern. I meant to let you know that a couple weeks ago I went ahead and just replaced the wires for both the pedal and the lead to power. What happened was I removed the casing of the plug where they join, saw that it appeared there may be a short between two wires there, but when I went to chop the insulated cables to start with a fresh area, I realized the casing of each positive and negative had deteriorated, to the point it appeared the entire cable was one long short! Must’ve been hanging on by a thread (pun intended) at the thrift store when I tested it. Anyway, went to the local hardware store, found some equivalent guage insulated cords, and attached them in the same fashion as the old ones, which mind you was no easy task. Little pesky screws and all. But got it done, put it all back together, plugged the machine into a surge protector, and voila! No trips, no sparks, just smooth needle movement!
                Gotta say, I’m proud of my work, but more importantly, this really nice vintage sewing machine gets a second life, and the friend whom I recommend purchase it in the first place gets to put it to use! I’m really thankful, and relieved. And again, I have you to thank, if nothing more than for the inspiration. Thanks so much!

                  1. Funny you should mention that. So far no, as in still no power to that part of the house, but tomorrow I’m planning to do some diagnostics. The basic plan is shut off power to the whole house (not knowing which breaker is associated) and then pull the plug assembly where the problem occurred out and just see what it looks like. If there’s a clear shirt there, I can take steps to replace it, then hope for the best, if not, probably have to get an electrician involved…

                    1. I think it’s going to be something other than a shorted plug. A shorted plug would pop a breaker for sure. Maybe a plug that’s now an open circuit and the fridge one is downstream of it… like Christmas lights when one burns out they all go out… Troubleshooting that could be a bear though if it’s not the one you were playing with. None of the plugs are GFCIs are they? That could just be a reset situation. Either way, with this much disrupted and the former state of the machine, you’re lucky you didn’t set something alight.

                    2. No gfcis, pretty old house. One of the plugs in that area had already “gone bad” according to the owner (I’m actually just a guest in the house…) anyway, I will get to it and see what I see. Unfortunately it didn’t happen today, so we’ll see.

  7. What a great article and thank you for the clarification about how AC works. I think I had seen the site you refer to and I though something didn’t seem right about that. I’m curious as to what you think about just replacing these older pedals on VSMs with newer electronic pedals that don’t have the same risk in terms of electrocution and/or fire hazard.

    1. Hi Donna! Thanks for stopping by! 🙂 As for the pedals, as long as you get the ones that are made for two wire if that’s what the vintage machine is (some of the Kenmore machines went to 3 wire at some point where I’d still call them vintage), I think they’re perfectly fine. Some people say they have better control with the electronic pedals, and they’re certainly not as warm with prolonged use. Lower risk is always a good thing to me. 😉

  8. Thanks for your thoughts. I am familiar with the site you mentioned and also read her suggestions which, frankly, scared me. Although I have no connection to Sew Classic, I have found her instructions great. Since electricity isn’t my strong suit and I need to replace a motor on an old Kenmore 158, can you tell me if it matters which of the motor leads is connected to the terminal posts. The same question for a Singer motor…. I know that the motor leads connect to the black and red posts on the Singer, but I don’t know if it matters which of the leads coming off the motor attaches to the terminals…same being true of the Kenmore Thanks

    1. Hi!

      I have no affiliation to Sew Classic either, though I’ve sent a lot of business to her for people in the US. 😉

      The 158 Kenmores are made by Maruzen / Jaguar. The thing about Kenmore machines (and don’t get me wrong, they’re some of my favorite machines to use and service) is that their designs and configurations changed so many times that it’s really impossible for me to say without seeing the motor. It’s -probably- not an issue, but I wouldn’t want to say that and have you try it and have trouble. That said, there are a lot of replacement motors that can be bought that have an end on them so you don’t have to wire, just install, perhaps one is available for your model?

      Depending on the Singer and its vintage the answer is the same. There were so many changes to the machines as time went on that I can only say fairly definitively for the black machines – 66, 201, 15, Featherweight, etc – that it doesn’t matter. Once we move on out of that vintage, the wiring changed a lot, and in some cases make it so you can’t plug in backwards (wires too short to do backwards, etc) so I’ve not bothered testing them.

  9. The plug in the photo at the top of this article has the metal screw terminals installed back to front, leading to a dangerous bare live terminal protruding from the plug if plugged into the wall but not connected to the machine. The plug needs to be (while not connected to the mains) disassembled and the terminals rotated in the channels so that they do not protrude from the plug.

    1. Hi Ben, You are correct. I meant to mention that this plug was one of the “bad” examples. It was a photo I added when I changed the theme to one that used banners and forgot to edit the post. Thanks for pointing it out.

        1. I have a bad habit of leaving my own machines like this if I’ve found them like this and they don’t need to be rewired (one in a hundred machines) , “I know better” and all that, but for customer machines, they’re always fixed. A case of do as I say don’t do as I do. 😉

          I amended the post though, right at the top. Thanks for the reminder.

    1. Thanks for dropping by Lisa! I’m really glad to help. I saw the website address you put in, hopefully no one was hurt, prompting you to start this research??

  10. This post is certainly a keeper. I’ve also shocked myself by not taking the plug out of the wall socket before working on the wiring. That was a big oops.

    1. Hey Virginia, Thanks for your comment. I’m glad you enjoyed the article. I’ve been told that what you and I both did is called “sparkling”. I have come to the conclusion that sparkling sucks. 😉

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