Broken GE switchgear mechanism

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LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Hey, gang. I just returned from a service call for a switchgear problem at a Sears store in a mall, and I'm hoping someone here has some experience with this kind of equipment.

It's one of two fused switches in the section next to the POCO-tagged incoming section, which only has GF in it. It's the kind of switch that you turn the handle three times to close, and press a red button to open. The two-switch section is rated for 4000a, 480/277.

The model is a GE THPC 3412ET1. The problem is that turning the handle does not ratchet the mechanism. The number '1' stays in the window, although the red button goes in a bit, and I can feel that the mechanism is not engaging as it should when I turn the handle.

From what the store's maintenance guy said, this was after a power outage and POCO repair (outside the store), and something to the effect that, after power was restored, someone opened the switch by turning the handle again, instead of pressing the button.

I opened the switch and removed the front of the switch mechanism housing, but I couldn't easily see the problem. The problem is clearly mechanical, not electrical. The store manager is hoping it can be repaired without having to replace the entire switch.

So, does anyone here with experience with this gear have any ideas or suggestions? Is the mechanism repairable, or at least replaceable without having to have the POCO completely deenergize the incoming service? Where does one look for parts?

We do have a local GE distributor, but I hope to be armed with at least a modicum of knowledge before proceeding. As always, any help is appreciated.
 

wireguru

Senior Member
zog probably has one of the little arm ratchet dookickey you need that GE doesnt even have a part number for sitting on his desk
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Last edited:

rcwilson

Senior Member
Location
Redmond, WA
I repaired one with my former company after we broke it doing a ground fault trip test.

We got parts off an old unit we bought from a refurbished circuit breaker dealer. I'm not saying that is the best thing to do, but it gets the service energized.

You may want to test the GF shunt trip when you are done just to make sure the switch trips open.

Zog will have the best advice.
 

brian john

Senior Member
Location
Leesburg, VA
Is it the handle on the HPC (High Pressure contacts) or the operator on the switch itself?

Most likely the repair is a new switch, used switch or a rebuilt switch.

If you buy new, order a stand alone HPC n a cubicle with line load lugs cheaper that an open HPC.


I may have one in stock or have a lead on one if you can supply all the cat#'s
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
I repaired one with my former company after we broke it doing a ground fault trip test.

We got parts off an old unit we bought from a refurbished circuit breaker dealer. I'm not saying that is the best thing to do, but it gets the service energized.

You may want to test the GF shunt trip when you are done just to make sure the switch trips open.

Zog will have the best advice.
This one is after the GF, one of two mains, and it apparently feeds the air-conditioning panel(s).
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Is it the handle on the HPC (High Pressure contacts) or the operator on the switch itself?
This is the operator handle (see pic in link in post #3) not causing the closing mechanism to go from 1 to 2 to close. It turns, but doesn't ratchet. It doesn't require as much force as it should to turn.

Most likely the repair is a new switch, used switch or a rebuilt switch.

If you buy new, order a stand alone HPC n a cubicle with line load lugs cheaper that an open HPC.
I don't understand what you mean.

I may have one in stock or have a lead on one if you can supply all the cat#'s
The only number I could find is THPC 3412ET1, plus the job number, which I took to be the original equipment-order number: 182-49528.

The part that seems to not work is the rotating mechanism behind the large red plastic removeable cover. Again, see pic in link in post #3.
 
Last edited:

ATSman

ATSman
Location
San Francisco Bay Area
Occupation
Electrical Engineer/ Electrical Testing & Controls
Lack of Maintenance

Lack of Maintenance

Hey, gang. I just returned from a service call for a switchgear problem at a Sears store in a mall, and I'm hoping someone here has some experience with this kind of equipment.

It's one of two fused switches in the section next to the POCO-tagged incoming section, which only has GF in it. It's the kind of switch that you turn the handle three times to close, and press a red button to open. The two-switch section is rated for 4000a, 480/277.

The model is a GE THPC 3412ET1. The problem is that turning the handle does not ratchet the mechanism. The number '1' stays in the window, although the red button goes in a bit, and I can feel that the mechanism is not engaging as it should when I turn the handle.

From what the store's maintenance guy said, this was after a power outage and POCO repair (outside the store), and something to the effect that, after power was restored, someone opened the switch by turning the handle again, instead of pressing the button.

I opened the switch and removed the front of the switch mechanism housing, but I couldn't easily see the problem. The problem is clearly mechanical, not electrical. The store manager is hoping it can be repaired without having to replace the entire switch.

So, does anyone here with experience with this gear have any ideas or suggestions? Is the mechanism repairable, or at least replaceable without having to have the POCO completely deenergize the incoming service? Where does one look for parts?

We do have a local GE distributor, but I hope to be armed with at least a modicum of knowledge before proceeding. As always, any help is appreciated.

Larry,
What you describe is typical of a THPC frame fused switch. The cheap and dirty version (design-build crap) to a real circuit breaker that has an OCT trip unit found in more critical applications, data centers, hospitals, etc. I just worked on a 35 story bldg PM shutdown job in San Francisco with 5 switchboards where we upgraded 18 Westinghouse ground fault systems with this type of switch (including CT's & wiring!) in 1 day. Whew!, I am still tired!:grin:
They all happened to work fine. Usually this sympton describes the closing springs are not fully charging. This is a mechanical problem and occurs when the levers and mechanical linkage do not reset due to dried grease in the spring charge mechanism. The quick fix is to spray a good contact cleaner in every opening of the mechanism with the switch cover removed. Operate the charging handle as you spray with the red tube in the nozzle of the can. Do not use WD-40 as it is crap and dries up causing more problems. We use CRC brand. Then use a lubricating spray. After you spray and exercise over and over it should begin to recharge the closing spring, the window will show CRG or #3 and then handle will stop moving with a snap. Then push the close button and the switch should close.
If this does not solve the problem then, if it is a drawout design (found in more critical applications ie: data centers, hospitals, etc,) the switch should racked out and taken to a breaker repair shop as it is not field repairable and install a spare.
If it is a bolt-in (usually the case if it is a mall store; cheap & dirty:roll:) then you have to obtain a spare and unbolt it and replace during a shutdown (a real drag:D)
Good luck!:)

Tony
 

shepelec

Senior Member
Location
Palmer, MA
Same opinion here, a little loving and cleaning will usually fix that pesky ratchet system.

De-energized, brake parts cleaner works great for cutting the build up of crap.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Tony and Shep, thanx for the responses.

This switch only has an open button, not a close button. I'm hoping only the mechanism can be repaired or replaced without having to deenergize in order to replace the contacts themselves.

I will see if I can get any results by cleaning and lubing.
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
Tony and Shep, thanx for the responses.

This switch only has an open button, not a close button. I'm hoping only the mechanism can be repaired or replaced without having to deenergize in order to replace the contacts themselves.

I will see if I can get any results by cleaning and lubing.

Those are always fun, as you have to stand in front of it when it closes due to the last twist of the handle! We were trying to locate a replacement for an old ITE 400 amp breaker, Siemens makes a replacement, but it is not UL listed, so we had to find a reman instead. Another contractor broke the handle off by driving a lift into it,(the handle was at about 5') then hiding the evidence as much as possible. The bent cover at the bottom was a giveaway, along with a new conduit ran up the side of the gear to the deck at the same point.
 

wireguru

Senior Member
Tony and Shep, thanx for the responses.

This switch only has an open button, not a close button. I'm hoping only the mechanism can be repaired or replaced without having to deenergize in order to replace the contacts themselves.

I will see if I can get any results by cleaning and lubing.

without having to deenergize? really?
 

iwire

Moderator
Staff member
Location
Massachusetts
Tony and Shep, thanx for the responses.

This switch only has an open button, not a close button. I'm hoping only the mechanism can be repaired or replaced without having to deenergize in order to replace the contacts themselves.

I will see if I can get any results by cleaning and lubing.

Larry, schedule a shut down, go in off hours and take care of it.

No reason to do this hot and many reasons not to.

For one you already know the item you want to work on is faulty, you have no idea if that fault is limited to just what you think it is.

Another is the likelihood of a very high available fault current on the line side of that breaker. I think your better half likes having you around.
 

brian john

Senior Member
Location
Leesburg, VA
1. DO NOT do this energized, this switch is Broken and load with springs, a damage spring flying around between energized bus is the last thing you want.

As for my earlier comment. If you buy a used switch it is generally cheaper to buy a switch in an enclosure, single switch line load terminations, that a switch on a pallet. you will get better pricing.

If you feel it is just the handle (which I doubt from your description) I would buy a used switch and salvage parts.

I would buy a new or new/used switch, do a swap.

This is easier than monkeying around with the switch, most likely faster and a guaranteed fix.
 

zog

Senior Member
Location
Charlotte, NC
De-energized, brake parts cleaner works great for cutting the build up of crap.

Also will break down the grease in the mechanism and ensure this switch never works right in the future. We call that "Technition in a can", quick fix with long term problems.
 
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