How do I wire this?

[alistermorton]

The capacitors cause a phase shift in the windings to create the rotating field. As Tim says, look up synchronous AC motors.

[nuttytechy]

I'm clearly no expert

 

Seems fine with me. It does indeed look a bit weird to somebody expecting two wires to run straight to the motor, so I think it's a fair question.

 

Actually - Big Clive's channel is an excellent way to understand how some of the Chinese designs actually do pretty clever things a bit craftily. Especially the ones where he pulls something apart and then details how the circuit works. He gets surprised too on many occasions by the innovative ways they do things - I watched a great one on a faulty led string light - where all the individual filaments inside the glass appeared to be in series - and he worked out that this meant it would need over 600V to light them up - and that's exactly what the circuit inside did!

 

My experience with Chinese things is that they don't pay much attention to earthing at all. Metal cases could easily be grounded, but never assume they actually are. Sometimes inside there's even a ground connection - but the box isn't drilled to bolt the tag to.

 

We diverted into PAT - which is always a bad move as it produces so many arguments, we also crept into CE=China Export, which is a European explanation of something that doesn't exist. Tiny changes in font, and we're convinced CE is not the standards mark and is some kind of Chinese export marking. One of my Chinese sources laughed when I asked a question on it. The CE marking on most cheaper, short run products is simply stamped on, and any paperwork simply printed off with old product text deleted and new one stuck on - just the same as happened years ago with BS Kitemarks. We shouldn't get uptight about this. I PAT new stuff, and occasionally one fails - usually because the chassis is missing the earth. Fixing it generates a PAT pass. Do we need to go further? We're quite happy building our own bits and pieces at whatever technical level we are competent at individually. I can't see much difference with Chinese kit - once you take sensible precautions, and don't see the CE mark as a PAT pass.

 

 

I only mentioned PAT because it being a motor with metal housing and we have no idea on how it is going to be used, it will be safe to have it earthed. I had a class ii dvd player which I wasn't happy about it because after time there would be mild shocks from it as it was leaking current onto the metal housing and as my kids were using it also then instead of doing the nice thing of fixing it, I said to the wife that we must get a new dvd player plus tv and surround sound system. I sort of turned a mountain out of a molehill ** laughs out loud **. Everything has a shelf life including class ii and once something breaks down and it involves kids... Excluding the wife ** laughs out loud ** then I would rather have the item tripping out a breaker than having one of my children being subjected to electrocution.

[Shez]

I had a class ii dvd player which I wasn't happy about it because after time there would be mild shocks from it as it was leaking current onto the metal housing

That's actually fairly normal when you connect together several class II AV appliances. The mains filtering results in a usually measurable 120v appearing on the chassis / signal ground. The available current is far too low to cause injury but you will get a tingle from it.

[Karel Bata]

This is a mirrorball hanging from an inaccessible point (no one will touch it) and the case is earthed. If it weren't I'd likely have put an earth in myself. http://www.blue-room.org.uk/public/style_emoticons/default/wink.gif

[ImagineerTom]

I was very careful in my choice of words - asking for advice on the internet about an unknown device is fine; by specific problem was your boasts that you are a competent person and routinely do pat / pat style inspections because you know what you’re doing.

 

The fact you can’t recognise a capacitor, don’t understand the basics of how different voltages would affect motors or that the “A” in ac stands for alternating means that if you ever are involved in a claim the opposing insurers (or barristers or h&s executive if it got that far) would be able to call up this single posting to show that you lack the basic knowledge to qualify as “competent” and you’d be hauled over the coals. If only to protect your own ass the advice that you have someone more qualified do your inspections / testing is the most important advice you can take away from this.

 

Sorry to be so harsh but this is exactly the sort of situation the pat / electrical safety regs were put in place to address - you’re enthusiastic and well meaning but you don’t quite have enough knowledge to be properly safe so need a second pair of eyes until your skill set and experience is up to standard.

[bigclive]

How intriguing. If the two black wires are going into the same terminal then it does hint that maybe the motor is 110V with a series capacitor to allow 220/240V use. The other capacitor is most likely for phase shift to set a rotational direction. That's very odd for a mirrorball motor and suggests that it will be single direction as opposed to running in a random direction like most standard mirrorball rotators.

 

If the white wire is purely feeding one end of a capacitor rated for 250V AC or 400V or more DC then there's no risk with powering it up with the blue and white wires as you think, but only if there is a ground/earth connection to the case for safety.

 

Better still, if it is a dual winding motor then it might be reversible by swapping the green and yellow wires.

 

I'd say that you're right and that the blue and white wires are the power supply. I'd suggest using the white wire as live and blue as neutral, with the earth wire going to the mounting hardware of the motor body.

 

What are the marking on the motor? I'd guess is is a 110V unit.

 

Where did you buy this from? It's intriguing.

[Karel Bata]

Tom, "don’t understand the basics of how different voltages would affect motors or that the “A” in ac stands for alternating" When on Earth did I say anything like that? Sorry to be harsh, but you made that up.

 

 

 

Clive, the motor says 110V 220V, 3-5W, 60Hz 2.3 rpm, 50Hz 1.9 rpm. Chang AN electric company, which it turns out is in Taiwan, not China. I got it on eBay from a hire company selling off old stock and bought a dozen assorted for a song! This one I'd cannibalised a while back for something else and stupidly didn't make a note of the wiring. Putting it back together I'm stumped by a pair of blue and white wires. But I gave it a go earlier today, and it works. It looks rather like this

 

But not quite

[ImagineerTom]

Karel, the questions and statements you’ve made so far show that you don’t understand those key points. Just as one example

 

I think the extra capacitors and wiring are to do with handling both 110 and 240 AC without needing an in-between stage. Not my area though.

 

The details are Irellevant though; you’ve freely admitted you don’t have a clue about a lot of this and I’ve pointed out that contradicts your other claims about being capable / competent for testing and certification purposes which opens a huge legal can of worms for you. My friendly advice is that you shouldn’t be admitting this on a public forum where it will come back to bite you AND that you should consider getting someone more experienced/qualified to help you in the real world for a bit; you’ll find it very beneficial.

 

I’ll dip out of the conversation at this point since we’re at risk of repeating the same points adinfinitum.