Thicknesser; which Amp supply?

[russ_1380]

Hi

My thicknesser that I bought about a year ago has still not been used

Its an old Whitehead Junior model.

The person who I bought it off said it has been converted to single phase (was originally 3 phase). However when I tried it with a 13 amp plug it started to spin and then blew the fuse. An electrician friend came an had a look, he seemed to think that although its been converted to run on single phase the initial ooomph the machine requires to get it going is too great for a 13 amp fuse.

I can't get hold of my friend so perhaps you guys could offer some advice:

-would it be possible to fit the machine with a 16 amp plug instead? Is this likely to make much difference?

-The Brookes motor (from memory) looks original. Do you think this was the original motor or do you think its more likely he's put a replacement single phase motor of similar age in the machine? Can a 3 phase motor be converted somehow to run on single phase supply?

The reason i ask; if it is a 3 phase motor converted, is there any way to convert it back to 3 phase? If so it may well be less hassle for me to run the machine in 3 phase guise from a phase convertor. I also have a 3 phase pillar drill that would benefit from the convertor to help bring it back from retirement.

What do you pros think?

Russ

 

[bubbabear]

You will need a motor fuse and not a standard 13 amp fuse, or you could use a "C" type or curve mcb instead of the more usual type "B" .The C type is like a slow blow suited to motors with a high torque start. Some motors can pull 2-3 times their running current on startup and can easily blow a standard fuse. So a 16 amp socket with a 16 amp type "C" breaker to protect it will enable the motor to start ok and will still give you protection against overloads and shorts. I would say your sparky friend is right.

 

[Stoday]

Look at the plate on the motor: it will tell you if it's single or three phase. It will also give the full load current.

It is not generally possible to convert a 3-phase motor to single phase. You can persuade a three phase motor to run with a single phase supply but the power will be very highly reduced. It's unlikely that you would be able to run the original machine by converting it's motor; you could use the converted motor in a different application that does not need so much power. A gramophone turntable perhaps :lol: :lol:

 

[russ_1380]

Thanks guys.

I think i understand what you are saying, but i will pass the information on to my pal.

Maybe the machine has always been single phase then, it was a while ago since I bought it so can't remember what the seller said fully.

Shame its had no use though, it looks a nice sturdy cas iron job like my Wadkin saw. Let's hope i can power it up soon!

When my pal last looked at my garage I think his plan was to fit a new consumer unit in the garage, purely for my machines etc. The idea being if anything blew or tripped it would only affect the garage not the whole house.

My table saw definetely id single phase (had a new motor fitted). Its got a normal 13 amp domestic socket on it and seems to work fine, although I don't use it often. Would there be any advantage to convert this to the 16 amp socket whilst I'm at it? or would this be a dangerous idea? (obviously I mean get my electrician friend to do it not me, you can tell i'm not very clued up on electrics!)

 

[Carlow52]

2 suggestions: read this
https://www.ukworkshop.co.uk/forums...in-the-home-workshop-updated-iss2-t35143.html

Post pic of plate on motor

both of these steps will give u best chance of getting correct advice

 

[russ_1380]

Cheers Carlow

i have a copy of that 9 fingers book, excellent piece but well above my head.

I'll try and get the motor plate details again on here but from memory it was a bit of weird one when I posted last time i.e. didn't really give much details.

If I get time tomorrow I'll have a gander

 

[Digit]

From what I recall of that machine you are not going to run it on a 13 amp supply.

Roy.

 

[russ_1380]

Hi guys


Was feeling a bit better today so managed to see the motor plate again with a mirror and torch (plus lots of patience!!)

The motor is a Brooks Motor lmt from Do??field England

1 Ph(ase)
2 hp
11 Amps (preceeded by two letters but can't make them out)
50 cycles
230 / 240 v
Speed? 1450
Rating CMR

I couldn't find Watts on the motor plate though?

Thats as much as I can read on the motor plate, there's a couple of other numbers (think serial number etc) but can't read them. I think the only way to clearly view the plate is to remove the top part of the thicknesser, I don't really fancy this as it would involve removing pulley etc.

On a side note there is a small cylinder on top of the motor (capacitor?). Here's what that said:

DALY

138- 183 UF
275V RMS
MSML 1 (?) 58C

Is this any use to you guys to help me work out what amp supply i'd need?

Cheers

R

 

[Digit]

Watts are Amps X Volts.
11 Amps would normally be preceeded by FLC, ( Full Load Current).
11 Amps at 240 Volts is 2600Wats, (2.6 Kilo Watts, kw) which is about right for a badged 2 HP.
BUT, it's the start up currnt that is your problem, not the running current.
Depending on such things as the mass of the motor's rotor, pulleys, belts and cutter block the start up current can exceed 11 Amps by a considerable margin.
A 16 Amp Type C MCB might do it or you might even need a 20 Amp MCB.
The other unit is indeed a capacitor.

Roy.

 

[russ_1380]

Cheers Digit,

I'll speak to my pal when he's about next. He's semi retired now and still busy so it's very hard to get hold of him at the moment.

Is possible to do what we were planning i.e. fitting 16 or 20 amp sockets in a domestic garage? The plan was to have them on their own fuse box (or whatever the modern equivalent is (consumer unit?), anyway you know what I mean, the idea being have all the machines on its own circuit so if it did go pop everything inside the house should still work.

 

[Digit]

Your description would be the best method.

Roy.

 

[russ_1380]

Thank you Roy.

I can't wait to get the thing up and running! It looks a bit tatty at the moment though so made need a full rebuild but I'll worry about that when I come to it