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Wiring an electric motor

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taffinnorfol | 18:35 Thu 15th Mar 2007 | How it Works
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I am a woodworker and have just bought an old saw bench table (cast iron no less!). It came with a really heavy electric motor - Higgs Motors of Birmingham, type H operating on AC, 2BHP, 200volts, 50 cycles, 1 Phase, 14.15 amps, linked to the sawblade axle by two V belts. My question is this:- the terminals for electrical connections are A1, A2, Z1, Z2. To which do I connect positive, negative and earth????
Additionally, has anyone got any idea how old it is - the reg. number is 286799!
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A is your running coil
Z is your starting coil

there should be some sort of earth clamp within the terminal box.

As for wiring it up.... It depends, are there any drawings on the inside of the motor terminal box lid? Usually come with something inside (like a sticker).

I would usually wire it up: Live to A1 (copper bar from A1 to Z1 using copper bar), Neutral to A2 (copper bar from A2 to Z2 using copper bar).

I'd wait for addition answers before you try this, dont wana be responsible for blowing you up!

If you do have any copper bars in the motor a decent sized piece of wire will do. This will energise the starting coil.

Hope this helps!
Question Author
Cheers priceyclause - it's at times like this that I realise that I should have concentrated on physics at school! I do appreciate your help. There are no diagrams inside the terminal box lid sadly but I can see the logic in what you suggest and will wait for other comments. Any guess as to the age? It looks fairly new conditionwise but oldish in design!
I'm no expert myself , but if Z is the starting coil and its wired permanently across the live & neutral it might burn out if the motor doesn't have a centrifugal switch, does it have one or being a very old one is it a hand start? as taffinnorfol says wait for more answers.
Although I can't help you with your wiring. I can say that a google found no current hits for Higgs Motors, Birmingham, but this American history archive has a document mentioning a Higgs bench grinder from November 1935.

http://www.iop.org/EJ/abstract/0950-7671/12/11 /410
Question Author
Thanks mortartube - wow that IS old! Altho the motor appears in little used condition, the internal wiring looks about that age as it is wax / canvass wound rather than later rubber / pvc. It'd be great to get the old girl going!
-- answer removed --
Question Author
Thanks eddie51. I think I agree with you. The motor is a monster of a thing - cast iron housing etc and a real beauty, looking almost new in terms of condition. Luckily it is simply bolted into the lower body of the saw table and connects to the saw spindle via vee belts so I can easily put in a more modern motor if necessary. Maybe I'll offer the motor to a museum!
Give these guys a call....if you get the right one they can be very helpful......the wrong one can be a bit offhand....lol....grumpy old *******.

http://www.kellysearch.co.uk/gb-company-610504 21.html
Give these guys a call....if you get the right one they can be very helpful......the wrong one can be a bit offhand....lol....grumpy old *******.

http://www.kellysearch.co.uk/gb-company-610504 21.html

Some comments here too:

http://www.eng-tips.com/viewthread.cfm?qid=538 88
Question Author
Hi tracerfire! Great info and thanks but now I'm spooked about connecting it up at all as the spec. plate says it's 200 volts and I could blow it up using standard 220 / 240. The other thing that's worrying is that I simply cannot find an earth clamp in the terminal box! Maybe they earthed the body to a mounting bolt in those days???!!!
You might be better of getting another motor on ebay. 1/2 HP upwards I would think. 240v single phase. They often go for around �20 - �30

http://search.ebay.co.uk/search/search.dll?sof ocus=bs&sbrftog=1&catref=C6&from=R10&satitle=s ingle+phase++electric+motor&sacat=-1%26catref% 3DC6&sargn=-1%26saslc%3D3&sadis=200&fpos=Postc ode&ga10244=10425&ftrt=1&ftrv=1&saprclo=&saprc hi=&fsop=1%26fsoo%3D1

Typically there's not much of a selection at this time.
Question Author
Hi mortartube, Many thanks! I think I'll eliminate the risk of getting all burnt and frazzled from wiring it wrongly by taking the good advice! I will keep my eyes open for something appropriate. If anyone knows a good source for a suitable motor, I'd be glad to hear!
I have same motor 1.50hp 240volt @ 50 cycles and the wiring order is :-

A1 is bridged to Z2 and Z1 is bridged to A2 so main power is
fade to Z2 and Z1.

If you need further info. You may contact me on
( [email protected] )
You have good strong motor no need to change to new one.

Good luck from John

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