Capacitor question!

[Dino]

Hi guys,

Few of you might remember me from a while back asking about my lathe starting issues (here) a while ago.

Well I just got back from holiday and finally got work settled and got to taking the thing apart and cleaning it. That's all done.

I bought this capacitor from ebay as one of the users suggested however...when I got it and finally cleaned my lathe and opened the capacitor it looks like this.

My question is how do I actually connect my new capacitor to the lathe? There is a part where the wires on the old capacitor link into some from the lathe, is it simply clipping them onto the new capacitor?

Thanks folks. I appreciate you helping out a novice like myself.

 

[midnightlunchbox]

Cut the wires and use crimps? Not that I'm a sparky though!!

 

[CHJ]

Yes it's a case of just cutting the wires off the old capacitor and connecting to the new.
Best done with some crimped female spade tags if the capacitor has terminals as opposed to wires.
Otherwise crimps or even chocolate strip.

Leave 20-30 mm of wire on the capacitor if possible just in case this was not the problem then it can be re-used some other time.


One word of caution, was the capacitor you ordered RUN Rated or just Start Rated? the link you posted is only Start rated.

It should be RUN Rated for that motor as it stays in circuit all the time.

As the load on it is lower when running and if the new capacitor is good quality you may get away with a Start rated for some time without it overheating, but fitting it will at least prove it was the capacitor that failed.

 

[Dino]

I linked the exact one - I'm totally new to any of this tinkering stuff which is why I ask.

I'll look for a different capacitor and probably link here when I find one. I'll do some hunting later tonight after dinner.

Really appreciate all the advice.

 

[CHJ]

This is one source, if you look at others on the site you may find another that suites the size of the housing better.

 

[parvum]

Hi The capacitor you have bought has solder tags, not suitable for crimps. I would suggest you buy a 450V !0 micro farad run rated capacitorfrom Maplin, either direct or online. These have tags suitable for standard automotive spade connectors which are readilye available from Halfords, ebay etc.The wrong cap can explode, not nice

regards Paul

 

[Dino]

I can't seem to find any on the Maplin website Paul...and yes, avoiding exploding sounds like an excellent idea.

 

[parvum]

Hi Dino, Sorry the cap you need is Maplin N34 KG £4.69, if your lathe is a single phase 230V machine or to err on the side of safety the 440V version is RG65V, £5.49. I mess about with three phase motors and make them run, well enough for wood lathes on common or garden mains electricity(230V AC). I am agreat beliver in safety margins especially if they don't cost much!the website is a challenge! Whatever you do do not use a capacitor that is described as electrolytic, it will go bang in this application,well maybe phutt.

regards

Paul

 

[Dino]

You're a star Paul. I'll pick some up tomorrow.

Also are these the connectors I need for them?

And this is going to be a stupid question but...if my lathe is 240v can I put the 440v in it? I really need to get an electronics for dummies handbook...

 

[CHJ]

Yes, you need the higher working voltage because although you know the mains as a nominal 230 volts it can have very high spikes way above this when switches operate etc. These spikes can punch a hole in the capacitor insulation if it is not robust enough.

 

[parvum]

Hi Dino, Chas is quite correct, not that he needs my endorsement! but the connectors you have linked to are too small you need these, Maplin JH82D ,the colours relate to the wire size, reds should be fine, but please use a proper crimping tool to fit them, a cheap plier type (not ordinary pliers!) will do, but if you plan to do more of these joints, the compound ratchet type makes a better and easier job. Expect to pay about £25 though on ebay.A crimp joint is often better than solder,especially if the joint is subject to vibration.

regards
Paul

 

[woodpig]

The 380V Capacitor I bought at Maplins for my belt and disc sander had 1/4" male spade connectors so you'll possibly need the blue ones. If in doubt just ask in the shop, they'll sort you out with the right size.

 

[Dino]

I've a friend who knows his electronics who said he'd be happy to drop down and fix things up for me.

I'll be heading to Maplins today to grab the items. Thanks very very much folks!

 

[Random Orbital Bob]

This thread has sparked a long dormant brain cell. I too am close to useless where electronics are concerned and wondered if you wise old sages out there know of any good books that take a the vacuous (me) towards the virtuous (you) in terms of electronics for dummies.

I'm OK with home electrics having renovated an ancient oak framed cottage and built my current house from scatch...its more to do with motors and what if something goes wrong. Is there a decent book that takes the beginner somewhere further than I am that anyone recommends?

 

[woodpig]

Two spring to mind. The Workshop Practice series has a book "Electric Motors in the home workshop". There is also "Electric Motors" and "Three Phase Conversion" in the same series. I downloaded a free ebook entitled "Electric Motors" which is very good but you'll have to google for it.

 

[woodpig]

I bought a book about Electricity many years ago as I thought it was worth knowing a bit more. I gave up on it quite quickly though after reading about the "error" on current flow. Have a read of this and tell me if you still want to know more ... :lol:

http://amasci.com/amateur/elecdir.html

 

[Random Orbital Bob]

I want pragmatic guidance not vibration stats of sub-atomic particles!!

 

[dickm]

or even better, find a reference on here to Bob Minchin's invaluable .pdf about motors.