Help with electric motor please.

[Julian]

Are there any motor experts out there among the throngs of visitors we attract these days?

I've had a couple of these motors for many years and have finally found a use for one, but I'm at a loss as to how to connect it up.

The rating plate gives 240v 1ph 0.33hp  2.6A 1430RPM   It's an AEI Kapak motor ... so old but quite a good make.

No information in the terminal box.

Connections are as follows ...





and the circuit (as I see it) and ohm readings I've measured are ...



Appologies for silly sized drawings, but I lost CoralDraw in a computer upgrade and I'm struggling with inkscape!

There is no capacitor fitted and no indication that one has been removed ... I guess one could have been fited remotely, but I think that's unlikely and my lathe motor appears not to be fitted with a capacitor as far as I can see (can they be fitted internally?), but it does have a centrifical switch.  I've spun this motor shaft using a chord (lawn mower style) and can't hear a switch ... not sure if I've spun it fast enough.

So, questions are ...

1) how do I wire it up?

2) can 1ph motors start without a capacitor (I thought not)?

3) Why are both windings the same resistance, from searching it would seem start and run windings have diferent resistances?

4) if it needs a capacitor where do I put it and what size / rating should it be?

Any help very much appreciated.

[knighty]

remove the A1 > Z1 link

check if there's any connection between the A lines and the Z lines

if not, put the link back in and connect power to A2 and Z2


....because there'll be no other way to wire it up?

you could try it with a low fuse first

or... wpin it with a drill and see if power is generated at any of the terminals?

[Julian]

Ohm readings were done with the link removed and I tried every combination of terminals and ground.  Those shown above were the only readings I got.

I've just spun it with the cord and got 2.3v between A2 and Z2.

Power to A2 and Z2 was the only conclusion I had come to too, but I'm reluctant to try things without knowing why I'm doing them.  I'll try it as a last resort if no one else chips in with any more info.

[Tony]

Does this help?

https://www.ukworkshop.co.uk/forums/anyone-have-an-idea-how-to-wire-this-old-lathe-motor-t64626.html

http://www.sentridge.com/wp-content/uploads/wiring_1ph.pdf

[Julian]

Snap!  I Iooked at both of those a couple of days ago.  Compared with the forum post, my motor is missing a link.  I guess it could have been lost when it was disconnected, but  there would be no need to disconnect both ends of the link,  I'll have a peek at the other motor and see if I can get any clues from that.  Also the OP doesn't say if the motor is fitted with a capacitor or not.

The diagrams all show capacitors but I still don't know if they any were fitted to this motor.  I might have to dismantle one to check for sure if a centrifugal switch is fitted ... I guess if it has a switch it must have a capacitor.

Still a little puzzled!

[Keef]

I can't help with wiring the motor but I think I've got Coreldraw7 up at the caravan if it's any good to you?

[Julian]

Thanks for the thought, but I have a copy of Corel 10 and that won't run on the new PC which is Win10.  Just about all my software which ran on the old XP machine wont run on the new one which is a real bummer.

The new PC was quite reasonable at £300, but to upgrade all the software I have would probably be ten times that cost ... yet another example of big business grabbing everyone by the short and curlys.

[knighty]

you could run your old programs inside a virtual machine?

they changed virtual machine with win10, but it's still there, and still free

I use it at work on a win7 machine running 3 winxp virtual machines - I use microsoft map point for planning deliveries, but they don't make it anymore and I can't find it to download anywhere, so I run the free 14day trial it comes with

(as long as you don't close the program you can keep using it for as long as you like)

[Julian]

Very interesting.  I've had all sorts of problems with Win 10, not just with the software, but with some hardware too ... my old scanner won't run for example.

Then there was months of problems with the thing switching off during sleep (seems quite common looking at various forums).  I initially tried Dell but after several call and remote sessions they decided it was an MS problem and washed their hands of it.

I then went through three levels of MS tech support, numerous remote sessions and several reloads of windows, none of which managed to solve the problem.  They finally announced they couldn't fix it ... great.  Back to Dell making threats of "not fit for purpose" and "my contract is with you not MS" before they eventually agreed to take it back.  It worked for a while and started with the same problem after an update.

Many more hours of my time later I worked out it was the HP printer driver causing the problem. Now whenever it updates, I have to try and stop the print driver up dating or delete the update and use the generic windows driver ... real pain in the arse.

It beggars belief that big companies can get away with selling products that don't work and expect the buyer to devote many hours of their time solving their problem.


Anyhow rant over!!! I've just looked for virtual machine on this PC and can't find it ... all suggestions seem to point to downloading an "app".  I've have heard my Techie mate mention virtual machines before so I'll have a chat with him and see what his recomendations are.

Many thanks for pointing the out, I really struggle to do lots of things without CorelDraw.

[Julian]

Just looked at the second motor and it's exactly the same.  Same single link and no signs of any capacitors having been fitted.

[Julian]

So, the mystery deepens.

I pulled one of the motors apart and there's no centrifugal switch fitted.

I sorted through my pump collection and found two motors not fitted with capacitors.  One only had only two connections in the terminal box and the other had the same designation for the terminals as the motor I'm looking at, but (looking at my second diagram) had A2 and Z2 linked.  The live and neutral were on A1 and A2, but there was a noticeable difference in the ohm readings between each winding. Without dismantling it, I'm not sure if a centrifugal switch was fitted.

Any more ideas anyone?

[knighty]

stick a 3amp fuse in the plug and fire it up, there's not much else you can do at this point


it might pop a 3amp fuse even if it's wired up right (startup current and all that)... but that's the best place to start from

[Julian]

You're right, it dose seem the only option now, so I tried it.  Mains on A2 and Z2 and it worked ... sort of ... rather disappointingly ... quite pathetically!

Nothing went bang which was a bonus but it turned at a snails pace, about as fast as I can spin the shaft between finger and thumb.

So what next?  Many diagrams have another link between A2 and Z2 and power on Z1 and Z2, but all that I've seen have capacitors and or switches ... anyone any thoughts?

[knighty]

if the As are linked and the Zs are linked it doesn't really matter which way around you have the positive and negative for an ac motor

sounds like it's duff to me

if you have others of the same design try one of those? - if it acts in the same way then they probably need wiring up differently... if the 2nd one spins up as normal then the 1st one is probably duff ?

[photoman290]

have you metered the windings ? if it doesn't have a switch or a cap it must be a shaded pole motor. from what you say it sounds like it has 2 windings. if so one of them will be a start winding. that would explain the low power. but in that case it should have a switch or a cap? or as knighty says its knackered. there are not that many  options for single phase motor connections. 2 phase and 3 phase have more but we won't go there.