200HP Induction Motor and Vapormatic starter....

[chris vine]

Hi All,

Now before you start saying that this is not model engineering I must come clean and say that the only link is that it is in a local engineering company which is very helpful in allowing me to use some of their large machinery and supplies to assist in my ME activities. The company is run by a friend of mine (obviously).

The question to any of our Electrical type members concerns the starting of such a monster:

The motor has come on a hydraulic pump test bed which was surplus at another firm and has now arrived up here. It is a 200hp 415v Mather and Platt machine. 1420 rpm. The electrical control gear for it is something I have never come across before and have no intention of trying to recomission for them as it is completely outside my experience!

The starter is called a "Vapormatic" and seems to be contained on 2 or 3 large control cabinets. Including one which contains lots of plastic tanks with large electrical connections. (I am assuming it is some sort of soft starter using some variable conductivity of a vapor??)

Does anyone know if this type of starter is completely obsolete or is it the sort of thing that an experienced electrical engineer would be familiar with? The temptation is to look at some sort of 3 phase to 3 phase inverter drive as this might be cheaper than a lot of time spent on the old system. How much might a 200 hp inverter cost??

(Yes, before you ask, the company is already discussing with Scottish Power the question of using the machine on the premises supply.)

Hope this is interesting rather than just off the wall..

Chris.

[Myford Matt]

HI Chris

I've sent you some info'. They are starters for use with slip ring motors:

www.lmphotonics.com/slipring.htm

Hope it's of use

Cheers

Matt

[jackrae]

Chris
www.nhp.com.au/ecat_content/NHPECatData/PDF/A06/Liq%20Res%20Vapormatic.pdf
It's amazing what you can find on Google
Jack

[chris vine]

Hi Jack and Matt,

Yes the Google stuff is interesting. This is clearly the type of thing it is, but of a different make and looking very old etc. I am still wondering if this type of stuff is really current (pun not intended) or out of the ark (arc?).

I will have another look at the data plate on the motor. I do not think it is a slip ring type because when I turned it (apart from having a huge inertia), it was very free and rolled to a stop with almost no friction of the type I would expect to see with brushes.

It just says Induction Motor. What would it say if it was a slip ring type? I don't think the starting cycle is particularly arduous because the pump it is driving would only be loaded up with back pressure once it is up to speed.

Chris.

[wayne]

Chris

I also suspect that the motor has a wound rotor with brushes even though its ac, this type of motor was comon on large pumps with a high starting inertia ( dont forget the head of water). If i am correct in the type of motor i think you have, they are still in use today and now use an electronic starter to vary the resitance to the windings on the rotor as the motor starts and gets up to speed.

I would have a word with a motor rewinder, they will provide good advice, i can provide you with a name of a firm in bradford who we use

Or contact the manufacturer at www.matherplatt.com, there pumps are still going today including some very old ones

[steam4ian]

G'day Chris

I have experience with the Vapormatic's cousin the "Statormatic", the concept proved very reliable even in a harsh environment. The "Statormatic" is a primary resistance starter whilst the "Vapormatic" is a secondary resistance starter used for wound rotor (slip ring) induction motors (WRIM). The differentiation was made in Oz but may not have been made elsewhere.

It is still likely you have a WRIM due to the size, the pump load with a high initial torque and the name "Vapormatic". Slip rings do not have as much friction as a commutator partly due to the amount of graphite in the brushes. The name/rating plate should mention rotor volts/amps, there may be two terminal boxes, certainly there will be six active wires.

The technology is still viable, dare I say current, and is much simpler than any electronic equivalent.

I think the Vapormatic equipment is manufactured in France.

Regards,
Ian