Old motor starter?

[Robotstar5]

Seeing a pic of something similar reminded me of the motor starters we had in the foundry where I did my apprenticeship in the 70's so probably 50's/60's "technology".
A metal tank, presumably oil filled with a winding handle on the side and an ammeter on the top, you had to wind the handle slowly, keeping the ammeter below a certain reading, if you wound too fast the unit would trip.
Just wondered if anyone knew what they were called or how they worked as never seen one since.

 

[snowhead]

Bet Tony will provide a picture and explanation, but Googling finds;

Oil Immersed Manually Operated Auto Transformer Starters

Modern version

http://2.imimg.com/data2/UC/FE/IMFCP-2067734/productview_os_big-250x250.jpg

 

[Knobhead]

Know absolutely nothing about them.
Have a look in the sticky section for a description of how they work.

These were made by G Ellison. Dependant Manual Operated (DMO) Oil Circuit Breaker (OCB)
View attachment 14890

Liquid starters were mainly made by Allen West
View attachment 14891

The gubbins inside a smaller AW starter
View attachment 14892

Finally one of my drawings
View attachment 14893

 

[Knobhead]

They were used for slip ring motors. The winding handle you mention was to reduce the SL resistance. You can see it in one of the pictures

DMO OCB’s were also used for either star/delta or autotransformers. They were exactly the same kind of switch just wired differently.

View attachment 14894

 

[Robotstar5]

Thankyou for the info both, I've got a few names I can research/google now. I do remember the starters on 250 hp motors could only be used once every 20 mins as the oil would boil!. One of Tonys pics remindd me of one of my jobs was to go round checking & topping up oil in the Allen West overload dashpots.

 

[Knobhead]

It would be the liquid starter that limitedd the number of starts. They were filled with water and caustic soda, great fun when we had one boil over!
Did you have a look at the motors sticky thread?

 

[Bobster]

It would be the liquid starter that limitedd the number of starts. They were filled with water and caustic soda, great fun when we had one boil over!
Did you have a look at the motors sticky thread?

They don't use costic soda anymore, due to environmental and h&s reasons.

 

[Robotstar5]

Did you have a look at the motors sticky thread?

Yes I did, spent a while reading it all, thanks for taking the time to post it.

 

[Knobhead]

Rob, the latest ones I worked on were from the 70's. Maybe they should be like me, retired

 

[Des 56]

A an apprentice we had one in the early seventies in a motor house for a mile long conveyor, taking waste from the colliery to the tip
It being uphill and the conveyor loaded when starting.it was a handy little job starting it on a freezing winter day,

 

[Robotstar5]

We had a lot of conveyors in the sandplant at the foundry and the control panel floor was the roof of our cabin, if one belt stopped it would stop the rest to prevent sand build up on the stopped belt. There was a warning horn for this but we didn't need it as bang of all the contactors dropping out used to shake the dust down on top of us!.

 

[Sparkattack]

Stumbled across two of these Allen West on the name plate.

 

[bomjac]

Plant I worked at in the steelworks had 4 of these babies, each used to start a 4MW synchronous motor. Motor would run up to speed on the liquid starter as a squirrel cage motor before a changeover switch knocked the 3 phase slipring rotor off and into the synchronous mode.

The whole building used to vibrate when these started, and the theory was that we had to call the sites Power Station to make sure they had enough rotating reserve to take them. Many a stop day was spent with 2 of us sitting either end inside the slipring housing with a length of emery cloth bedding in new brushes.