Historic mains voltages?

[John_BS]

A friend of mine has managed to aquire a brute of a donkey-saw which is driven by a 3-phase Brook Motor. The name-plate says 520V: I've never come across this before, and wondered if anywhere / anytime in the UK we might have had 300V single-phase supplies? Or would this have been an in-house factory-specific supply?

John

[JonSnell]

You may find it is a 3 phase 415v motor with 520v as the peak phase angle voltage.
Crompton may be able to advise if you contact them. www.brookcrompton.com

[Radio Wrangler]

With a motor on something that's likely to have been worked hard, always look to see if there are any signs that it's been re-wound. If so, the plated ratings may have changed without the plate being up-dated.

David

[John_BS]

I'm going to check the terminal block. Motor (6-pole) dates from the 60's. NB my father worked for Brook Motors all his life, and was an expert on induction motors. I have a book "The Induction Motor", an update from an original which BM Ltd published in 1954 as "Alternating Current Electric Motors" . Covers switch-gear etc as well.

[MotorBikeLes]

Is it possible that the saw (or just the motor) started life in Canada. A pal of mine has an old miller with similar voltages originating there.
Standard UK motor coil voltages are 230/415 and 415/720. The first are derlta for 230, star for 415, the second are 415v delta and 750v star.
520 definitely a "strug" or very old from a specific locality.
I don't think you will get much info from Brook. When I made enquiries about a "bought new" motor for a pal, I was told the factory that made it shut 10 years before, and there was no info available.
Les.

[Radio Wrangler]

Well over ten years ago. St Thomas Road, Huddersfield. Part of the site is a casino and the other part a 'Christian Fellowship' place, the sign on the outside says. Rather strange neighbours.

Brooke's got amalgamated with Crompton Parkinson, and then 'rationalised' out of existence. They made very good motors.

David

[broadgage]

In years gone by, industrial power supplies often in the range of 500 volts to 550 volts, DC, and later AC at similar voltages.
Such supplies were usually 3 phase, 3 wire with no neutral.

I have never heard of a 3 phase, 4 wire supply at 300/520 volts. Someone, somewhere probably used such a supply, but it was never widespread.

Who wants a 300 volt supply ? Too high for lighting* since about 250 volts* is considered the sensible upper limit for general purpose incandescent lamps.

500 volt to 550 volt supplies were a useful voltage for machinery back in the day, less voltage drop than at 400/440 volts, but still considered as being low voltage (the upper limit of "low voltage" was once 600 volts. It is 1000 volts these days)

Might possibly be American ? Some old American lamp catalogues list 300 volt lamps "for mines" and this could imply a 3 phase 4 wire supply at 300/520 volt.

To this day, industrial power supplies in the USA are often 3 phase 4 wire at 277/480 volts.

*Lamps for 277 volts, 300 volts, and other higher than 250 volt circuits DO exist but find little favour. They are less safe, less efficient and less reliable than lamps for lower voltages.

For factories with 3 phase 500 to 550 volt power supplies several options existed for lighting.
1) Retain gas lighting, zero capital cost if already existing.
2) Obtain a second supply from a power company at DC or lower voltage AC.
3) Use lower voltage lamps in series, often five lamps in series as in trams.
4) Use low voltage lamps from transformers, 50 volt 300 watt lamps were popular for this purpose.

[russell_w_b]

Originally Posted by John_BS

'A friend of mine has managed to aquire a brute of a donkey-saw which is driven by a 3-phase Brook Motor.'

What else does the rating plate say? Any chance of a photo of it?

[ex 2 Base]

It brought a smile to my face when I read of the suggestion of contacting contact BrookCrompton, they will know. Well, about two years ago a friend brought along a Brook Crompton two capacitor motor with an an unusual internal switch and ask me to reconnect it. I am familiar with motor. Being a bit cautious, I thought give them a ring. I spoke to a technician and explained, he not one of ours mate he said, in spite of me having the motor on the bench and I couldn't convince him. Later found out Brook Cromptom Parkingson and many other BRITISH motor manufactures are actually owned by a Chinese company and many of the motor are made in Bulgaria.Ted

[John_BS]

I've yet to find a definitive history, but here's what I know so far:

Brook Motors Ltd thro to 1970, then bought by Hawker Siddeley and amalgamated to become Brook Crompton Parkinson.

At some point manufacturing in and around Huddersfield & Doncaster moved to Eastern Europe

Name changed to Brook Hansen / change of owner?

Name changed to Brook Invensys / change of owner

2002 sold to Lindeteves-Jacoberg of Singapore

https://www.theengineer.co.uk/invens...rook-crompton/

Name changed back to Brook Compton ? date

I think Broadgage is probably right regarding a local industrial power supply, so no single-phase derivative.

[John_BS]

Here's another date and name-change confirmed:



https://drivesncontrols.com/news/arc...is_reborn.html


I have a motor badged Brook Invensys which I installed on my bandsaw.

John

[russell_w_b]

Originally Posted by John_BS

'...and wondered if anywhere / anytime in the UK we might have had 300V single-phase supplies? Or would this have been an in-house factory-specific supply?'

There were some funny voltages used in coal mining: 380 / 660V 1 - 3-ph. for example. But you would hardly expect a machine like that down the pit.

Sounds a bit 'in-house-ish' to me. I note some inverter controllers for sale are adjustable to 520V O/P, so 520V sounds like it's a thing.

[Ed_Dinning]

Hi Folks, it will certainly be a bit low on power at 415v, not 520 and the slip will also increase so it will be down on RPM a little bit, as it is a 6 pole motor it may not be too bad.
If you want full power an auto transformer might be a cheap way to go and should be quite compact

Ed

[David Simpson]

Best bet John, let us have a picture of the motor's plate showing all it's spec.
Running a 520V motor on a 415V supply would seriously alter its torque/speed graph, therefore making it's switchgear prone to "dropping out".
How is it coupled to the "donkey saw" ? Shaft driven or belt driven ?
David's sad reminiscences of the Brook Motor's factory in Huddersfield, and other folks info on subsequent eastern European/Chinese take-overs, are a sad reminder of the state of British Engineering.

Regards, David

[John_BS]

Originally Posted by David Simpson

Best bet John, let us have a picture of the motor's plate showing all it's spec.

Regards, David

? have you read back ?



I'm not actually asking for motor advice, but if anyone happens to have a 3 phase transformer that might be of interest!



John

[David Simpson]

Aye, John, just put out a new thread post in the "Wanted" sub-section. David

[Maarten]

Originally Posted by John_BS

? have you read back ?

I'm not actually asking for motor advice, but if anyone happens to have a 3 phase transformer that might be of interest!

John

In practice that could be the same, solving the problem. Especially if you don't find a transformer and for example a VFD or other modification would be needed. Or even to simply know the required power of this transformer. In general, for the best forum result, you just tell the forum everything you know and have on the matter, and not keep back what you think wouldn't be useful.

[John_BS]

This thread is actually about UK mains voltage standards of the past. I'm sorry that it's become diverted by kindly advice about 3-phase motors, which was not the intention!

I think we've established the following:

Nowhere ever had 300V ac single-phase supplies
Some factories migh have used 500+ V 3-phase internally

Thanks for all the replies, and Mods, this thread can be closed.

John