# 1600-amp Pringle Switch Problem



## 500TFEngineer (Dec 22, 2009)

I'm working at a new building that has a problem with one of three pringle switches on the main 3000-amp switchboard opening due to voltage imbalance. I had eaton cutler hammer come out and replace the 3-phase voltage monitor relay six months ago (one of the time delay settings was faulty) and it is now doing the same thing again. I observed it's operation and it opened due to a unbalanced phase (Led Light) condition which was set at 8%. I removed the monitor and sent it to the manufacturer and they bench tested it and confirmed that it is working fine. I also want to add that the other two pringle swithes that are fed from the same P.G. & E. power source have not tripped. I suspect that there is a problem with the switch itself and was hoping someone could shed some light on this problem.


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## Zog (Apr 15, 2009)

500TFEngineer said:


> I'm working at a new building that has a problem with one of three pringle switches on the main 3000-amp switchboard opening due to voltage imbalance. I had eaton cutler hammer come out and replace the 3-phase voltage monitor relay six months ago (one of the time delay settings was faulty) and it is now doing the same thing again. I observed it's operation and it opened due to a unbalanced phase (Led Light) condition which was set at 8%. I removed the monitor and sent it to the manufacturer and they bench tested it and confirmed that it is working fine. I also want to add that the other two pringle swithes that are fed from the same P.G. & E. power source have not tripped. I suspect that there is a problem with the switch itself and was hoping someone could shed some light on this problem.


IS this a new installation? Was any testing done? Chances are there was a mistake made in the installation, PT polarity wrong maybe? Please post any test results you have.


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## 500TFEngineer (Dec 22, 2009)

*Additional Information-1*

After the voltage monitor was replaced the first time and the same thing started to happen with the new one I did the following. I shut off all the downstream disconnects (10-for this Switch) and reset the 1600-amp main. Within a day the Switch opened again. I checked the voltages and they are 480-495 volts across the phases and approx. 277 volts to ground. When the technician from cutler hammer was out the second time he megged the bus and the readings were good. So, that leaves me with the control transformer for the ground fault device, the voltage monitor (already tested okay), and a capacitor connected on the control voltage circuit. After the holidays I want to have someone bring in a voltage recording device and see what the voltages are on the line and load side of the switch when the switch opens. There is essentially no load on this switch as the building only has one small tenant and they are getting there power from the second 1600-amp switch on this panelboard, which again has never tripped. I would have the manufacturer fix this under warranty but this is an issue that hasn't been resolved.


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## McCaa (Sep 3, 2009)

Are the phases actually unbalanced? Being you have done so much already, I would check the phases and see how unbalanced or if they are unbalanced. If they are within the 8% factor that is opening the switch. Is it possible to alter some of the loads and rebalance that and take off a couple percent and bring that down a little?

I would start there from what you've already done. If you can rearrange the load balance 2% and the switch still opens, I would say the switch is bad and needs to be replaced.

Before I would replace the switch though I would through a data/power logger and it and see what's happening when the switch is kicked open and see if there is anything going on that's unseen.


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## DipsyDoodleDandy (Dec 21, 2009)

*Puco*

Have you ruled out PUCO yet? Reason is we had something like that last year and it was on their end something shorting out.


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## Zog (Apr 15, 2009)

500TFEngineer said:


> After the voltage monitor was replaced the first time and the same thing started to happen with the new one I did the following. I shut off all the downstream disconnects (10-for this Switch) and reset the 1600-amp main. Within a day the Switch opened again. I checked the voltages and they are 480-495 volts across the phases and approx. 277 volts to ground. When the technician from cutler hammer was out the second time he megged the bus and the readings were good. So, that leaves me with the control transformer for the ground fault device, the voltage monitor (already tested okay), and a capacitor connected on the control voltage circuit. After the holidays I want to have someone bring in a voltage recording device and see what the voltages are on the line and load side of the switch when the switch opens. There is essentially no load on this switch as the building only has one small tenant and they are getting there power from the second 1600-amp switch on this panelboard, which again has never tripped. I would have the manufacturer fix this under warranty but this is an issue that hasn't been resolved.


Did anyone check the proper installation and ratios by testing the PT's sending the input to the voltage monitor? 

You may want to have a real testing company come look at this, they are certified to do acceptance testing on these and can also do your power monitoring if needed. 

*Hampton Tedder Technical Services*
4571 State Street
Montclair, CA 91763
Phone: (909) 628-1256 x214
Fax: (909) 628-6375
Web Site: http://www.hamptontedder.com

*Power Systems Testing Co.*
2267 Claremont Ct
Hayward, CA 94545-5001
Phone: (510) 783-5096
Fax: (510) 732-9287
Web Site: http://www.powersystemstesting.com


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## JayH (Nov 13, 2009)

Here are the guys I use.

http://www.pacificpowertesting.com/contactus.htm


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## Zog (Apr 15, 2009)

JayH said:


> Here are the guys I use.
> 
> http://www.pacificpowertesting.com/contactus.htm


Not NETA certified, never heard of them.Thier website says they are "Certified" but for this type of testing that would require a NETA certification (NICET no longer has a certification program in this line of testing).


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## JayH (Nov 13, 2009)

Zog said:


> Not NETA certified, never heard of them.Thier website says they are "Certified" but for this type of testing that would require a NETA certification (NICET no longer has a certification program in this line of testing).


Try giving Steve a call. If he is not certified to help you he will have no problem pointing you to someone who is.


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## Zog (Apr 15, 2009)

JayH said:


> Try giving Steve a call. If he is not certified to help you he will have no problem pointing you to someone who is.


I think I will pass, I am a level IV Certified test supervisor for power systems, I also involved with the certification process. "Steve" is making false claims about certification. I already pointed the OP to 2 different certified power testing companies in CA, you can find more at www.netaworld.org

You can also learn about certification of power system testing companies and techs and what the importance of that is there.


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## JayH (Nov 13, 2009)

Zog said:


> I think I will pass, I am a level IV Certified test supervisor for power systems, I also involved with the certification process. "Steve" is making false claims about certification. I already pointed the OP to 2 different certified power testing companies in CA, you can find more at www.netaworld.org
> 
> You can also learn about certification of power system testing companies and techs and what the importance of that is there.


 
That is interesting information. I think I'll give Steve a call after the holidays and get a little more clear on certifications.

We have not had a problem with acceptance of his company on any of our state projects and I'm going to have to plead ignorance on requirements as far as NETA is concerned in California.


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## brian john (Mar 11, 2007)

So with the phase monitor removed did it trip?

Is their indication of the phase failure?

Is the phase failure the only device on the switch or is there GFP and blown fuse?

I doubt seriously it is the switch, I is one of the protection devices.

I service Pringle's and repair them regularly.


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## JayH (Nov 13, 2009)

Brian, are you NETA certified?


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## brian john (Mar 11, 2007)

JayH said:


> Brian, are you NETA certified?


At one point I was, certification stays with the company. I see no reason to give good cash to an association. To date (24 years) it has not impacted me on any projects.


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## 500TFEngineer (Dec 22, 2009)

*Additional Inforamtion - 2*

Below is a follow-up to the posts I've received in the last week. 

1. During the construction period in mid October of 2007 an acceptance test was done by Power Systems testing company of Hayward, Ca. (NETA Certified) which included the 1600 Amp. "A" core feeder switch. The equipment used was a Megger & DLRO. The report indicated visual inspection was OK, arcing blade action was fine, arcing blade alignment was good as well as all other inspection & operational checks. The contact resistance was between 10-12 Micro Ohms on phases A-C. The Megger test done at 1000VDC was documented at 2,000M Phase to Phase and Phase to ground. So, based on the reports everything checks out "Good". :blink: To put this in perspective the Electrical contractor lost the original copy of the acceptance test so the one I received at the end of construction ( over a year later) was pieced together by Power Systems Testing as they had deleted the original archived data. 

2. In addition to the phase monitor the feeder switch also has a Ground fault relay and blown fuse indicator lights. However the only device that has caused the switch to open is the voltage monitor (Phase unbalance indicator) which has been checked by the manufacturer.

3. Since the last time the switch opened I bypassed the voltage monitor before putting it back in service and it has yet to fail again. Keep in mind that the other feeder (C-core feeder switch) as well as the main ahead of the feeders have the voltage monitor intact and they are not tripping. 

After the holidays I will be making arrangements to have someone come in and set up metering to see what the voltages are between phases when the switch opens. I am looking to see if it's consistently on the same phase and perhaps the duration of the voltage drop when it is at it's trip point. I have learned that the bolted pressure switch applies pressure between the fixed and movable contacts when closed and I think that one set of the contacts is out of adjustment or faulty. I know that this is not a common occurence but neither is the tripping problem that I am experiencing. So, has anyone had the bolted pressure checked and adjusted because it was out of tolerance? If not, based on what has been done already what else could it be within the switch or auxillary equipment causing this type of problem?


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## Zog (Apr 15, 2009)

If it had 10-12 microhms I doubt you have a contact pressure issue, however it may have came out of adjustment in the last year, but doubtful. 

I still think you may have an issue with the PT's, has anyone checked these? If not that then you may have a intermittent voltage issue from the utility. Are you sharing your feed with another building or is it your own dedicated utility feed?


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## 500TFEngineer (Dec 22, 2009)

If it's a utility feed issue, why is it not affecting the other feeder switch or main which both have monitors on them ? The power from P. G. & E. comes from a substation in the area.At the service entrance in our transformer room it feeds two transformers, one for MS-1 panelboard that the A & C core switches are fed from and the other transformer is dedicated to MS-2 which feeds the roof mechanical equipment, chillers, boilers, fans, and also emergency power.


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## brian john (Mar 11, 2007)

What has moved to the front of the line for the number one reason mains open are phase failure/phase imbalance relays.

Put a new one in it should be warranty,l but they are cheap bite the bullet if necessary and go for it.


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## brian john (Mar 11, 2007)

DipsyDoodleDandy said:


> Have you ruled out PUCO yet? Reason is we had something like that last year and it was on their end something shorting out.


\


Other than a lose of power activating the phase relay, PLEASE explain how a fault upstrweam of the main line will cause a GFP or blown fuse device to operate?


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## RIVETER (Sep 26, 2009)

*pringle switch*

It is my understanding that EATON bought out the PRINGLE company. If that is true the EATON people should be able to troubleshoot their equipment.


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## brian john (Mar 11, 2007)

RIVETER said:


> It is my understanding that EATON bought out the PRINGLE company. If that is true the EATON people should be able to troubleshoot their equipment.


Eaton did buy pringle, and you can wait for a tech from Tennessee or call a local expert.


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## RIVETER (Sep 26, 2009)

*Pringle switch*



brian john said:


> Eaton did buy pringle, and you can wait for a tech from Tennessee or call a local expert.


We seem to have them, EATON, at our plant a lot. We are constantly changing out switches for testing. They have all been very professional and I have learned a lot from them.


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## DipsyDoodleDandy (Dec 21, 2009)

*loss*



brian john said:


> \
> 
> 
> Other than a lose of power activating the phase relay, PLEASE explain how a fault upstrweam of the main line will cause a GFP or blown fuse device to operate?


that's what it probably was. There was a big wind storm that night and power was down for a bit they said


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## brian john (Mar 11, 2007)

RIVETER said:


> We seem to have them, EATON, at our plant a lot. We are constantly changing out switches for testing. They have all been very professional and I have learned a lot from them.


They are great guys to work with, but generally I prefer to see locals hired (like myself) then bring in the factory on non-warranty issues


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## j johnson (Jul 20, 2009)

cheak for harmonics


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## brian john (Mar 11, 2007)

j johnson said:


> cheak for harmonics


And PLEASE tell me how that would affect anything.


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## Zog (Apr 15, 2009)

brian john said:


> And PLEASE tell me how that would affect anything.


If you dropped a harmonica across a phase to groud it would cause the GF relay to trip the switch :whistling2:


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## Bob Badger (Apr 19, 2009)

Zog said:


> Not NETA certified, never heard of them.Thier website says they are "Certified" but for this type of testing that would require a NETA certification (NICET no longer has a certification program in this line of testing).


How is a NETA certification required?

Who is the authority requiring it?


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## brian john (Mar 11, 2007)

Bob Badger said:


> How is a NETA certification required?
> 
> Who is the authority requiring it?


NETA and some government agencies and a few AHJ's, but push come to shove it holds no power.


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## Bob Badger (Apr 19, 2009)

brian john said:


> NETA and some government agencies and a few AHJ's, but push come to shove it holds no power.


Pretty much what I was assuming.


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## Zog (Apr 15, 2009)

Bob Badger said:


> How is a NETA certification required?
> 
> Who is the authority requiring it?


It is very regional, depends on where you live. Certian areas you can forget about any testing work unless you are NETA, other areas not many people care. 

There are a lot of specs that require NETA certified companies, these bids only go out to NETA companies so non-NETA guys don't see them and don't even know what they are missing out on. 

That said, I am no longer NETA. You don't have to be a NETA company tio know what you are doing, I would have confidence in someone like Brian testing my stuff. But at least you know they are focused on testing as at least 80% of thier business, thier techs are certified and have training based on power system testing, all the test equipment is calibrated, a registered PE will review all engineering reports etc...

http://www.netaworld.org/about-neta/benefits-of-hiring-a-neta-company


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## Zog (Apr 15, 2009)

Bob Badger said:


> How is a NETA certification required?
> 
> Who is the authority requiring it?


Never said it was, I said "this type of testing that would require certification". My point was the website referenced claimed they were certified, which they are not. Any "certification" for this type of testing would have to be a NETA certification. They are making false claims, that's all I was pointing out.


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