Seeking C.T. saturation curves 1

[rancher1]

I'm seeking saturation curves for some Westinghouse ct's. I haven't had any success searching the web and am hopeful someone out there could provide me some direction. BYM L spec 960742, curve sheet 697891. The other two, L spec 834355 and 885800 are the only data I could retrieve from the transformer N/P. Any assistance is appreciated. Thanks!

 

[Laplacian]

If you are not able to find the manufacturer data, you could at least plot up to the knee point on the curve yourself. Connect a variac (variable AC transformer) output to the CT secondary. Start from 0 volts and increment 1 volt at a time until you find the knee point while recording variac line current at each step.

 

[wyewound]

Try

http://www.wescodist.com/

or WESCO Distribution. They sell industrial electrical products. Another source would be

http://www.eaton.com

Eaton Electric owns the rights to many of the electrical products made by westinghouse today.

 

[ScottyUK]

Expanding on Laplacian's post, ensure the primary conductor is open circuit and not shorted by an earth switch or a drain earth when doing a mag curve.


----------------------------------

Sometimes I only open my mouth to swap feet...

 

[JensenDrive]

Did a little web browsing and this is the closest I found.

http://www.abb.com/product/us/9AAC720278.aspx?country=US

I see BYZ CTs but not BYM's. Beats me.

 

[randyman]

Try to contact Siemens Power Group in Orlando, FL. They are the keepers of all the old Westinghouse dwgs for many of the products that were built years ago. I am very familiar with BYM series but do not have those particular curves in my archives. I am not sure if they will provide it to you but I am sure they have it. Not knowing the current ratio I can bet you that the exciting voltage is well in excess of 1000V, and I know that the higher ratios have very high saturation levels, so if you attempt to excite the coil yourself be sure that you have a stiff source with the ability to reach 2-3kV (just in case). And most definitey follow ScottyUK's advice on opening the primary.

I may be able to guide you if you can provide the Westinghouse part number that is on the nameplate.

BTW, I am relatively confident this is not the same as a BYZ, which is for zero-sequence applications. The BYM were typically cast coils in large AL or Cu housings for use on generator terminals.

 

[rancher1]

Thanks to everyone that responded!

 

[JensenDrive]

That is surprising. I had not heard that Seimens had part of the old WH business. I am guessing that they purchased the power generation service group. Correct? If so, it seems they have no incentive to distribute the old WH data, so it seems sad they have it.

 

[davidbeach]

ABB has the former WH instrument transformer business, I doubt Siemens would be the place to look.

 

[ScottyUK]

Siemens took the turbines business. If the instrument transformer was part of a generator package then they might be able to help, otherwise David has the answer.


----------------------------------

Sometimes I only open my mouth to swap feet...

 

[randyman]

ABB in Pinetops NC has the Instrument transformers business, YES. However, the product line made by the Westinghouse IT group in Trafford PA was taken over by Siemens. When Westinghouse separated their business groups Siemens took the power generation section (except for nuclear). They changed the name from Westinghouse to Siemens-Westinghouse and now they have dropped the Westinghouse part and are Siemens Power Group. If you contact ABB-Pinetops I serioulsy doubt they would be able to help you unless it was an old Westinghouse product that was originally produced their in Pinetops - the BYMs were not. Believe me I know this as I am a CT designer and work very close w/Siemens on old Westinghouse CTs found on generator terminal bushings. This is why I asked for the p/n. I may not have the curve but I may have the O/L with some internal design info and can give you approximations.

 

[rancher1]

Thanks again to everyone for the feedback. The BYM's are externally mounted on an OCB. Cat.# 2289C67A12, same as part number?, C400 Rating Factor of 2.0, 600/5 multi-ratio. I have no data, other than the L spec number from the xfmr n/p, for the ct's internally mounted in a Westinghouse power transformer mfg date of 1980, 1200/5, mrct.