SF6 Switchgear Repair, who's doing it

[haze10]

Got a G&W SF6 4-way switchgear 25KV. Think a CT inside the tank went bad. Unit is 20 years old but in excellent condition. Do you know of any shop that is doing quality repair of SF6 gear. I'm on the East Coast but could ship it anywhere in US. Any leads appreciated.

 

[Overvoltage]

Have you asked G&W? Even if they aren't doing it themselves I would think they could suggest a subcontractor?

 

[haze10]

You would think!!!! But times have changed. When you call headquarters looking for help, they direct you to the area sales rep. they tell you specifically that we don't accept calls from customers. The sales rep is selling their products and 20 other manufacturers. So its a came of telephone; you ask a question, salesman calls factory for answer, answered is relayed back to you. You ask another question and cycle begins again. Good factory service ended in the 80's as the accountants, rather than engineers, started to run companies.

 

[Kiribanda]

I believe that this is a G&W (when G&W was doing business in BLUE ISLAND, IL,USA) 25kV swgr having the 4-ways (load interrupters and fault interrupters)
are inside a SF6 filled tank. That means if any component has to be replaced then you should have a plan to re-fill SF6 and to test pressure switches etc.
Since S&C are still selling similar SF6 filled swgr, you may get a quota from S&C to do the repair.
Since it is 20yr old I think that time has come to replace it by a 4-way 25kV solid dielectric swgr also from G&W so that no SF6.

 

[haze10]

Do you really believe that utilities in the US use 20 years as a threshold to replace high voltage distribution equipment? Would you have suggested that to GE when they were designing their Magnablast line of switchgear? Even if it needs to be replaced a customer should be able to converse with a factory rep regarding the problem. This is a $65K piece of equipment that is in near new shape except for one issue that might even be repairable outside of the tank. S&C may be an alternate, but again a big shop which is difficult to reach the techs that can actually help. I'm still leaning to a smaller shop that specializes and is anxious to talk with me to get my repair business.

 

[thermionic1]

The real problem is that the gear is very likely hermetically sealed. It's not made to be worked on, as it's 'maintenance free'. IN all fairness to the OEM, they likely did not manufacture the internal CT and CT's are generally quite reliable over time.

You may have to combine an electric service shop with one that specializes in hermetically sealed equipment (welding shop). The electric shop needs to have the equipment to remove and store the gas. Let the welding shop cut a hole for repairs. Let the electric shop replace the CT. Weld it back up, leak check then have the two work together for the vacuum of gear and refill / seal again.

I've removed gas on circuit switchers and we used a piercing fitting that connected to our gas recovery hoses. The fitting we pierced was had a copper tube that was used to fill the gear, which was pinched off, then soldered to complete the seal.