GE MagneBlast Breakers
GE MagneBlast Breakers
(OP)
would appreciate some help (verbiage) with an argument to replace my old 5kV MagneBlast breaker line-up with a new arc flash rated vacuum bottle line-up. breakers have been "sort of maintained" over their 35+ years - but the bus has really never been down for inspection/cleaning due to the process and system configuration. can anyone give me some ammo for my business case?
thanks!
thanks!






RE: GE MagneBlast Breakers
20 years ago it would have been GE IS&E. Cutler Hammer will probably do it. There are others out there but you should check the jobs they have done and their references.
Depending on the size of your gear you might save enough money to pay your salary for 4 or 5 years.
RE: GE MagneBlast Breakers
Arc-resistant switchgear has some limitations. It is only arc-resistant when the door are closed and latched. Also, it will be necessary to vent a large exhaust duct to keep the blast pressure down. Sometimes this is a problem in existing facilities.
David Castor
www.cvoes.com
RE: GE MagneBlast Breakers
As to arc-flash issues, there are remote racking devices available for this equipment, and remote control operation is pretty easy. This will give a bit better margin of safety for the old line-up.
Replacing the entire line-up of working equipment with something for the sake of "arc-flash", well, that depends on how excited your management gets about the safety aspects of arc-flash issues. They will have to put their own number to that, because if your Magne-blast gear is still working, there's an order of magnitude difference in refurbishing the old gear and replacing it with the new stuff.
old field guy
RE: GE MagneBlast Breakers
I get calls on these all the time, wanting to replace these because they are 50 years old, why replace something that has lasted that long without issues with something that wpn't last 20 years?
I specilize in these, we remanufacture them and provide roll in vaccum replacements.
RE: GE MagneBlast Breakers
RE: GE MagneBlast Breakers
Trip timing tests as well as trip current profile tests show these problems.
Much of the partial discharge issue comes about from aging insulation cracking and tracking. The tracking can be mitigated by inspection and good, thorough cleaning.
old field guy
RE: GE MagneBlast Breakers
RE: GE MagneBlast Breakers
Investigate upgrading the relaying to modern digital relays. You might be able to reduce arc flash for parts of the gear by implementing zone interlocking schemes that are not possible with old relays.
RE: GE MagneBlast Breakers
The second aspect i.e. the arc-chutes are made of asbestos. Asbestose causes skin cancer and has been band internationally. We should therefore take extra care while cleaning the arc-chutes. Special oxygen masks, I would suggest to be used by the maintenance staff.
I would therefore recommend and it will be far more economical to replace all these magne-blast breakers with Vacuum power or Power/vac replacement or retrofit breakers brought forth by GE or other vendors. These are direct replacement breakers and requires very little commissioning times.Hope this will assist to make up your mind.
RE: GE MagneBlast Breakers
These mechs have less issues than most VCB's, they were made back in the day we overdutied stuff.
Perhaps the biggest issue people have with these in the bottles in the gear, the potting that was used is a very common failure point and using a VCB as a replacement does nothing to address this issue.
THe biggest advantage to a VCB replacement is the reduced weight of the VCB, minimizes stress on the elevating mechanism, another common failure point.
RE: GE MagneBlast Breakers
Many sites base their inspection/maintenance requirements based on the agreements they reach with their insurers to maintain a low premium.
saludos.
a.
RE: GE MagneBlast Breakers
I will admit that I haven't seen too many cases where a breaker failed except in cases of extremely poor maintenance, but I still prefer horizontal racking breaker.
RE: GE MagneBlast Breakers
Interesting about the timing comments. I believe there is documented information (Zog?) detailing Magnablast breakers not latching closed because the new style greases now used allow the breaker to operate TOO fast.
I have seen early vacuum retrofits get stuck in the cells because they were TOO light and held in place due to primary contact tulip spring pressure. The early (80's) vacuum retrofit breakers were scary. Those companies that did them well still do. Those that did not got out of it (thankfully).
Zog made a good point about the primary bottles. If any of your breakers have dark colored tar substance dripping on the primary poles your simple breaker rebuild or retrofit project just got harder, longer and more expensive.