Transfer switch gone amuck

[bankruatsteve]

I have a transfer switch that a friend brought in from the states for me (and he got one for himself).  That was 3 years ago and everything good until today.  I was sitting as I usually do with my laptop on my lap in the easy chair and grabbed it to reposition when I got zapped contacting the ethernet socket.  <deleted>?  I got out the DMM and was getting 150v AC between me and the socket.  <deleted>?  I touch the ceiling fan that I know has a ground connection and ZAP..  I'm thinking this just can't be happening.  I check the watt meter that I have on my downstairs CU and everything looks normal.  But, sure enough there's abnormal voltage on the ground bar.  

 

I go upstairs where the mains enter and a watt meter connected to that and it's showing 18 amps!!!  <deleted>?  I unscrew the lids to the CU and the transfer box and don't see anything amiss.  So, I start up the genset and flip over to that expecting it to trip off but everything normal.  The mains watt meter now shows 0 amps.  <deleted>?  Desperate, I decide to start isolating things but what?  OK - the AVS.  I turn off the DPST isolator I have on the mains and remove the AVS from the circuit.  Back on the mains.  Switch back to mains on the transfer switch and 18 f_ing amps.  That leaves the switch itself.  So, everything off and I re-wire so that the AVS now outputs to the side of the transfer switch that normally takes from the genset.  On the mains.  Flip over the transfer switch to "genset" and  back to normal  - only 1.5 amps.

 

So, my conclusion is that the "mains" side of the transfer switch somehow started leaking to ground big time.  Now, I'm wondering why that didn't seem to bother anything except me when I touched something grounded.  (?)

 

I haven't started looking yet but if anyone knows where to get a new transfer switch in Udon Thani, please reply.  At this point, I will have to take out the wires from the AVS and re-connect the wires from the genset every time a power failure which has been daily lately.  But, what else would I have to do.  Not sure how long it was leaking 18 amps but imagine my next bill will tell me.

 

Cheers

[carlyai]

No good mate.

Been a lot of wet weather around there as well?

Could be an idea to have a look for ants or water first before you replace the switch.

It's just a thought, sorry if it's a wrong thought.

 

The reason I say this is because transfer switches (well mine anyway), seem to be very well made and robust. Also the problem didn't seem to happen while you were switching loads.

 

Sent from my SM-J700F using Tapatalk

 

 

 

 

[Crossy]

Before ripping anything else apart check your incoming supply polarity.

 

It's not likely if you've not had any work done but you could have a reversal.

 

18A is some leak to ground.

 

[bankruatsteve]

The beguiling thing about this is that there is zero evidence that a serious fault was taking place.  And why a switch enclosed in plastic could do that is crazy.

 

And now I'm wondering if my downstairs grounding has been compromised.  (?)  It's difficult to check because after making sure the crew doing the concrete left the rod exposed, the tiling guy pounded it down and covered because it didn't look good.  Grrr.  Is there any other explanation as to why my ground could get charged like that?  There are separate ground rods for each CU but I'm also sure they are, at least, "Ufer" connected.

 

I want to take the switch out for examination but now it would be a bit of a project to return to my original double switch setup.  Aagh.

 

BTW:  Removing the AVS output from the left side of the switch to the right side seemed to remove the fault.  The wire hanging down is from the genset - currently not hooked up.

 

Edit:  Polarity OK and is something I check every time I mess with the mains.

 

Edited July 22, 2017 by bankruatsteve

[carlyai]

I see your transfer switch is nothing like mine.
My comments about transfer switches was going off mine, which looks and sounds robust.


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[bankruatsteve]

@carlyai  Yeah, I don't know where my friend picked up the ones he brought.  They look like DIY where two DPST switches have been mechanically ganged.  I worked OK though.  I see yours is automatic - which I'm not ready for.  Where did you get that one?  And do you know if they have manual?

 

I'm still trying to work out something that makes sense for the fault in mine.  Deductive logic says that's the only place and when I moved the wires to the other side the fault went away so that's gotta be it.  I didn't get so much as a tingle when I took the cover off so the ground system upstairs must be working fine.  But, with 15 amps (I was reading 18 but normal for that time of day is 2-3) going somewhere it seems it would show in some form or another.  Again, I think I need to refurb my down ground as that was definitely charged up.  

[Crossy]

With 15A going into your rod it's going to get a good way above ground even if it's a decent one.

 

Take the switch apart, I'll bet the plastic has broken down (possibly from heat) and there's metal-metal contact round the back.

 

Then order one of these http://www.ebay.co.uk/itm/125-amp-changeover-switch-240V-mains-to-generator-transfer-single-phase-Din-rail-/272258677525?epid=1661900551&hash=item3f63e1bb15:g:ouoAAOSwxKtX~6d5

 

They do one in a box too http://www.ebay.co.uk/itm/Changeover-switch-230v-mains-to-generator-transfer-125-amp-metal-enclosure-125A-/272258676793?hash=item3f63e1b839:g:ia4AAOSw--1WsLjd

 

[bankruatsteve]

15 minutes ago, Crossy said:

With 15A going into your rod it's going to get a good way above ground even if it's a decent one.

 

Take the switch apart, I'll bet the plastic has broken down (possibly from heat) and there's metal-metal contact round the back.

 

Then order one of these http://www.ebay.co.uk/itm/125-amp-changeover-switch-240V-mains-to-generator-transfer-single-phase-Din-rail-/272258677525?epid=1661900551&hash=item3f63e1bb15:g:ouoAAOSwxKtX~6d5

 

They do one in a box too http://www.ebay.co.uk/itm/Changeover-switch-230v-mains-to-generator-transfer-125-amp-metal-enclosure-125A-/272258676793?hash=item3f63e1b839:g:ia4AAOSw--1WsLjd

 

Thanks Crossy.  I will need to order the box as I don't have DIN mount.  Do you happen to know if the box can be mounted to a wall using the normal anchors?  I would assume it can.  7 pound shipping - whatever.  I also assume you have ordered from there - you ever had any issues? 

[Crossy]

Yeah, I've used them in the past with no issues.

 

I've not actually seen the box, but one assumes it has holes in the back, screws / anchors no problem.

 

Small DIN boxes are available here but that metal box looks nice and large for those big cables

 

[Crossy]

They also do one in a plastic box which I think I would rather go for

 

http://www.ebay.co.uk/itm/Changeover-switch-125A-240V-mains-generator-weatherproof-enclosure-IP65-125-amp/262262389729?_trksid=p2047675.c100623.m-1&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D44760%26meid%3Dbf2d872eb832471bb588d77e2048caaa%26pid%3D100623%26rk%3D2%26rkt%3D6%26mehot%3Dag%26sd%3D272258677525

 

EDIT Or this from AliExpress.

 

https://www.aliexpress.com/item/2P-63A-230V-MCB-type-Dual-Power-Automatic-transfer-switch-ATS/32344513184.html?spm=2114.search0104.3.17.3jTskp&ws_ab_test=searchweb0_0,searchweb201602_3_10152_10065_10151_10068_10130_10084_10308_10083_10080_10082_10081_10110_10178_10137_10111_10060_10112_10113_10155_10114_5360015_10154_438_10056_10055_10054_10310_10182_10059_100031_10099_10078_10079_10103_10073_10102_10052_10053_10142_10107_10050_10051,searchweb201603_13,ppcSwitch_5&btsid=86a62d25-31cc-4953-a7a5-6e8823217397&algo_expid=de6a5b4f-a232-4ecd-87d0-93b5a95c9de1-2&algo_pvid=de6a5b4f-a232-4ecd-87d0-93b5a95c9de1

[carlyai]

Nice looking changeover switch Crossy.

[mention=87941]bankruatsteve[/mention]

Looks like the one you want. Mine is manual or automatic, got in manual mode at the moment.

Got mine from a Chinese supplier.

Think Crossy has the right answer.

 

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[bankruatsteve]

I liked the EBAY one so ordered that.  Thanks again @crossy

 

Given the above, do you agree my downstairs ground might be compromised and needing maybe a different GROUND?

[Crossy]

Just now, bankruatsteve said:

Given the above, do you agree my downstairs ground might be compromised and needing maybe a different GROUND?

 

If you managed to get 18A down it, it's fine

 

[Wirejerker]

If u had a RCD it would have tripped a long time before it got to 18A. Might be a good investment


Cheers

[bankruatsteve]

47 minutes ago, Wirejerker said:

If u had a RCD it would have tripped a long time before it got to 18A. Might be a good investment


Cheers

No it would not.  Edit: if you read my OP you would realize my problem is in FRONT of any MCB, RCD, RCBO.  Pay attention.

Edited July 22, 2017 by bankruatsteve

[bankruatsteve]

Aagh.  HELP.  Now, I notice that one set of yard lights are on all the time.  I re-check polarity and my tapes are good but the polarity is not.  I switched the wires and back to 15 A going somewhere.  So, went back to wrong polarity and OK.  What can explain this?  Where should I look?

 

 

[bankruatsteve]

Now, I am thinking this has to be something external.  I hadn't changed anything but all of a sudden things have changed.  The power  has dropped several times every day lately.  The polarity by PEA must have got reversed somewhere.  I think.  But, why would that cause a 15 Amp leak?  I'm going crazy here.

 

[Wirejerker]

You may have an active conductor damaged by a nail or screw and this has grounded giving you 18A. When u moved your wires on the transfer switch you reversed polarity so now the neutral is on the damaged wire and it's happy cause it's at the same potential as the earth, the active now has no switch so the lights stay on. I would look for the fault in the garden light circuit. Check you polarity at the CUs and before and after the transfer switch.


Cheers

[bankruatsteve]

OR maybe the problem IS with the switch and I somehow reversed polarity when I re-wired it.  I thought I checked but now I'm not sure.  What I now know is that both my CU's are in reverse polarity and If I correct that at the transfer switch, 15 A goes down the drain.  This is driving me crazy.  The switch I just ordered is supposed to be here within a week so will just wait for that.

[Wirejerker]

You can check out that garden circuit while u wait. Maybe it's a reo bar through the cable


Cheers

[carlyai]

Good thinking, wait for the switch. [emoji6]

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[bankruatsteve]

@Wirejerker again, pay attention.  Why would I have problem anywhere except with the switch?  My plan tomorrow is to eliminate the switch and see whet then.  It will make things sorry if I need the genset but would rather have things "normal".  

[Crossy]

@bankruatsteve Where is your MEN (N-E) link? Is it after your ammeter?

 

If so a polarity reversal will connect the live supply to your ground rod and your meter will read the current sinking into the ground.

 

Check your incoming polarity again. Use a voltmeter and separate ground rod (big screwdriver well away from your existing rod).

[bankruatsteve]

2 hours ago, Crossy said:

@bankruatsteve Where is your MEN (N-E) link? Is it after your ammeter?

 

If so a polarity reversal will connect the live supply to your ground rod and your meter will read the current sinking into the ground.

 

Check your incoming polarity again. Use a voltmeter and separate ground rod (big screwdriver well away from your existing rod).

No MEN here (thus no link).  I expect the incoming mains polarity is the same as it has always been but has now been reversed after going through the AVS (the wires are all the same color so must have inadvertently crossed when I moved to the right side of the switch).  

 

After several hours of contemplation last night and confirming this morning that I had the genset polarity wrong at the transfer switch and just never noticed it but would explain why the genset didn't have the leak.  So THAT could explain a different problem and one I hope to answer as soon as I can off the electric for a while.  If the problem is not in the switch (again, I just don't see any evidence there) the only other place it could be is in the cable from the mains (via AVS and switch) to my downstairs CU and specifically the cable that used to be live but is now the neutral.  Will report on that later.  

[Crossy]

With no MEN even a polarity reversal shouldn't cause current to flow unless your neutral is grounded somewhere inadvertently.

 

Could be time to look at those outside lights that don't go off.

 

[bankruatsteve]

There was never any current flow from the down CU other than normal (which is what the garden lights are on).

 

So after struggling for an hour pushing around 10mm2 wires (which I originally decided to go with for running from the mains to the CU's), I finally got the "Live" cable running to the down CU re positioned as the neutral and vice-versa.  Then, put the AVS output back to their original position in the transfer switch and viola - no leak and the up CU now back to correct polarity.  Now, I need to switch the cables in the down CU so that will have correct polarity. 

 

My conclusion to all of this is that what used to be the live wire from mains entrance to the down CU was somehow compromised and making a 15 Amp contact to ground or structure.  I suspect that fault still exists but now on the neutral and seems to not be a problem there.  But, I'm not going to wait for it to become a problem and will plan to run new 6mm2 cables around the outside of the house and just leave the 10mm2 to decompose or whatever.  The current run is through the attic and inside render (yeah - don't know why they did that as I was going to enclose in conduit when they finished).  

 

Anyone need a new transfer switch?  Actually, I will probably use the new one when it arrives as it looks like a cleaner package.  

 

Thanks to all (even Wirejerker) for hearing out my rants and giving your thoughts.  This one was trying to drive me nuts and damn near succeeded.

 

[bankruatsteve]

Hoo boy.  This is not at all fun.  So, I swap the "mains" in my down CU to bring back to proper polarity.  Go up, turn on the mains isolator and the watt meter rolls to 15 Amps.  SHIT.  Isolator off, go down and turn off main breaker, go up, isolator on, watt meter normal (just shows up draw).  Isolator off, go down, return cables to reverse polarity, go up, isolator on, watt meter normal.  <deleted> <deleted> <deleted>

 

So far, except for some lights that glow when supposed to be off, nothing seems to be bothered by the reverse polarity   It's not right but the alternative seems to be letting 15 A go off to nowhere and I don't want to be paying for that.

 

Attaching a crappy diagram.  Any ideas @Crossy ?

Edited July 23, 2017 by bankruatsteve
Forgot attachment

[Crossy]

14 minutes ago, bankruatsteve said:

So far, except for some lights that glow when supposed to be off, nothing seems to be bothered by the reverse polarity   It's not right but the alternative seems to be letting 15 A go off to nowhere and I don't want to be paying for that.

 

15A going somewhere is not good.

 

Does the on/off status of the individual breakers make any difference?

 

I'm sure you have a fault to ground somewhere, all you have to do is find it.

 

EDIT Is wattmeter B actually monitoring the neutral?

[Wirejerker]

I assume you are using an ammeter.. Wattmeters read in watts. By your diagram meter A is on the active. And B is in the neutral.. so you r checking to different paths. To shut me up disconnect the active and neutral wires for the garden circuit. With both wires disconnected use a multimeter on Ω (ohms) test that circuit for a ground fault.


Cheers

[bankruatsteve]

1 minute ago, Crossy said:

 

15A going somewhere is not good.

 

Does the on/off status of the individual breakers make any difference?

 

I'm sure you have a fault to ground somewhere, all you have to do is find it.

 

The thing is, the fault seems to go away when I put the down CU in reverse polarity.OR turn off the down main breaker.  Watt meter 'B' shows normal even when watt meter 'A' is showing 18 A.  IE: the 15 A fault seems to only occur when down CU is in correct polarity AND with some load.  Individual breakers will affect the watt meter normally but again, 'B' has never shown more than normal amps since this started happening yesterday.

 

With down CU in reverse polarity, both meters show "normal" so I'm thinking I won't find anything glowing or smoking in that scenario.  I don't know - just put in new wires and forget about it I guess.  Cheers.