Alternative for Joslyn Clark DC contactor for braking resistor.

[flexoprinting]

Hi Folks

Any alternatives to this unit, they are obsolete now and very expensive ($4000.00). My armature volts is 240V and 89A. The problem with these I think is the small copper square ring around the laminated plates, this ring cracks or opens and I'm thinking it is the culprit causing the contactor to chatter. I have spot welded the ring with good results but would like to just find a newer unit to replace these, we have three. Currently checking into an AB product.

Recommendations anyone?

Thanks, Chuck

 

[flexoprinting]

This is a pic of my iron with broken ring, not sure what the technical term is of course.

 

[jraef]

The technical term is a "shading coil", and yes, if it breaks, the contractor chatters.

Joslyn Clark still exists, but is this PARTICULAR contractor obsolete? 240V DC rated contractors should not be too hard to find, but harder than they used to be as DC falls out of popularity. Be careful though, the contactor must have a DC current rating, you cannot assume that an AC contactor without the rating for DC will work, DC is much harder to switch.


"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington

 

[melspuds]

Most shading coils are set into a sight machined groove around the iron from about1/8" to maybe 3/8' from the end. I have seen homemade coils that worked. Take a Cu wire about the same size as the shading coil, cut longer then needed clamp the 2 longest to the iron. Lay the shorter cuts across the top of the longest cut. Then braze or silver solder asc close as you get without hitting the iron. Remember the need to be tight against the iron.
Good luck,
Dave

 

[ScottyUK]

ABB's R-Series DC contactors were comparatively reasonable in price last time I bought some. Considerably cheaper than the equivalent from Telemecanique (now Schneider) or Siemens.

 

[melspuds]

If it DC Contactor, try Eatoazine

 

[melspuds]

It is past midnight
If you need a DC contactor try Eaton DC Crane Systems. SqD does not carry them anymore was bought by EC&M after the French bought SqD. EC&M has the best dc contactors around. Every crane in the steel mill that I retired from has nothing but EC&M (SqD) controls from 1 ton to 550 ton and about 40% of the rolling mills, Good Stuff.
Good luck,
Dave

ps google ec&m electric, not the magazine

 

[ScottyUK]

Forgot about Mersen, a decent range of medium to large contactors:

http://ep-uk.mersen.com/en/products/catalog/type/dc-contactors/

 

[flexoprinting]

Thank you Gentlemen! I will make some calls today, a spot weld/w wire feed temporarily saved the day.

 

[jraef]

Add to the list, Hubbell Industrial Controls.

http://www.hubbell-icd.com/dcIndex.asp

In A-Bs product lines, there is a version of the 500 line of contactors (500DC) that has DC ratings on it, but it is no longer in the catalog. Sales are too low to devote the bytes I guess. It is still available however, you just need to have your A-B distributor find someone that knows this. Old farts like me do, the young punks often don't, they just ask the computer which has no relational database function that can extend its reach that far...


"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington