Kit to test equipment and power sources?

[The Beatsmith]

Hi

Probably not 'the place' to talk about this kind of thing, but i thought i'd give it a shot anyway!

I have terrible problems with the master switch on the breaker box in my house, it keeps tripping (perhaps once a day, or maybe 3-5 times a week) and i cannot find a reason why. I've been through a million various trouble shooting methods too boring to mention, and can't find a specific reason. The landlady had 2 different electricians out a long time ago, but they never come back (probably because she doesn't want to pay more towards it). They both couldn't find anything obvious and would have had to return to look into it further.

I realise that there's a small piece of test equipment that you can plug into plug sockets to test them out, like this: Mains Socket Tester : Mains Socket Tester : Maplin Electronics

I plan to get one of those and check every socket in the house.

Is there a piece of kit you can buy to test your actual equipment/appliances (and plug splitter/surge protection units) to make sure everything's wired correctly?

I don't think it's my equipment as i've had most of it in other locations with no problems, but I just want to rule out so that i can argue with the landlady that it's not due to my equipment.

The trip doesn't usually switch while i'm plugging something in or turning something on, it's nearly always while everything is in a 'steady state'. It often does it while i'm out and nothing is on (but still plugged into the wall).

I know the problem is coming from sockets, too, as it's easy to trip the entire master switch if i flip the 'sockets' switch on the breaker box.

Anyway, if there's a piece of kit that can test my equipment/appliances, that'd be great.

Cheers

 

[JohnRoberts]

Obvious first question is service rated appropriately for your load? Or could you be overloading your service.

There are consumer power meters that you can plug appliances into and view the power draw, then add it all up to estimate load or identify a problem appliance.

Is it a thermal or magnetic breaker? I ASSume you are talking about a resettable breaker not a simple switch.

Resettable thermal breakers can degrade from repeated trips. (I have seen this with small product resettable breakers)

An experienced electrician from your corner of the world can probably advise you from his personal experience (replacing bad ones if that is a common failure).

or not, I obviously don't have first hand experience with GB main wiring. IIRC magnetic breakers are popular on the continent, but don't know what types are in dominant use in GB.  I would not expect magnetic breakers to share the same degradation from use that thermal breakers are guilty of.

JR

[disregard... i notice from the thread where you posted elsewhere on the WWW that the breaker is also GFI so that may be problem. either actual ground fault or faulty ground fault detector  /disregard]

 

[shabtek]

the switch may need replacing

 

[Andy Peters]

I'm with the others -- the breaker is old and tired and needs to be replaced.

I remember back at the club in Hoboken, every so often one of the circuit breakers which fed the PA would trip. And the more often it tripped, the easier it tripped. We had the English band Ride (or was it Loop?) in, and they brought a bunch of lights which they didn't advance and I told them wouldn't work, but you know the touring band never listens to the house guy, so after the third time running down to the basement to reset the breaker during the show, they finally got the hint and played with just the usual stage lights. And man oh manischewitz were they boring.

The final straw was Dinosaur Jr and J Mascis has THREE 100 W Marshall heads and the bassist had big amp too. (I asked J, "which of the three cabinets should I mic?" and he pointed to two of them, then I noted the big pedal board and asked, "So you've got some kind of stereo or channel switching thing?" and said, "no, it's just louder that way.") So we get input levels on everything, then I say, "OK, I'm ready for a song" and Murph counts off something and on the downbeat, BANG, the breaker trips.

Only it didn't just trip. It flopped around in the box like a noodle. OK, end of soundcheck, and the band were fine with that, and I called the local sound company and had them bring in a distro which they tied in and we were up and running in plenty of time.

-a

 

[PRR]

> master switch on the breaker box in my house, it keeps tripping

Reasons a MAIN breaker will blow:

1) Too much juice
2) Small juice leaking (maybe through person??) (Unlikely in US but possible in UK)

#1 Too Much Juice is maybe obvious. Room heater, toaster, tea pot, laser printer start-up, especially all together. If you have 50A main breaker, even a large apartment will get *hot* by the time a 50A main trips.

There is a $25 box, WattMinder? (what CJ says), which will tell the actual power draw of any plug-in appliance; however high-demand suckers usually get HOT so you don't need a gizmo to know why a Main may be blowing.

#2.... small stray leakage. If I stick my finger in the lamp socket while taking a bath, the GFIC (or RCB) will detect 0.030A leakage *out* of the circuit and trip-out before I die.

In the US, GFI on mains is not done.

In the UK, circuits are larger and in a smaller apartment you just might have one RCB covering all the circuits. The wise thing to do is separate RCB for each circuit so you are not left in total dark; however a small flat may not go this far.

> test equipment ... check every socket in the house.

??

In the US we call it a 3-light tester. This appears to be exactly the same except larger for your big plugs. It will "warn of specific problems such as Live and Neutral reversed, no Earth, etc."

It is very unlikely that this will find the problem which is tripping your Main. (It is fairly likely it will find problems; but in UK electric many of these problems are formal not practical.)

In US work, a somewhat better tester is IDEAL 61-152 SureTest Circuit Analyzer. ~~$200! It *may* find a N+E short (the 3-lite never will), which some GFI/RCBs are very sensitive to. It will not find "minor" leaks. This particular product is not adapted to UK electric system.

Basic no-tool steps: keep a record of when it trips, what was running at the time, if you jiggled any plugs, smelled any hot PVC, felt any tingle, heard your neighbor's pot-plant light timer flip on, if it was raining, anything.

I'm reluctant to offer advice from afar on a foreign system. I'd much rather your landlady or you pay the sparkies to come back for a half/full-day investigation.

However if you can photograph your CU (consumer unit; "fusebox" in US), as-is and also (if safe!!) with the wire-cover off, someone might be able to clarify what is there and what could/could-not be worth more investigation.

 

[CJ]

Kill A Watt works gud in US, do not know if they have a UK version,

 

[JohnRoberts]

There is an active thread on geekslutz forum with a picture of the panel/box

It is a common rcd breaker, but no obvious smoking (leaking) gun.

My vote is to swap out the breaker JIC it is squirrely...

JR

PS: What is the standard fine for dual posting?

 

[The Beatsmith]

Hi guys,

So sorry for not getting back to this thread - i wasn't able to figure out how to enable post notifications (fixed now)! And apologies for the cross posting on Gearslutz too - i have posted about this problem before a few times in various places and often didn't get any response, so i wasn't expecting any/much!

As John mentions it's a common RCD breaker (picture attached - it's the left master switch which trips), and the load is not too much for it as far as i'm aware. I've checked all my studio equipment (as well as the fridge, dishwasher, a few other usual culprits) using a "multimeter on resistance range and measuring the resistance on a three pin plug of each device (switched on but obviously unplugged from the wall) between the centre ground pin and the outer line and neutral pins." None of the gear showed any problems.

I also calculated the total wattage for all my gear and it's only 3000w. So i'm pretty sure it's not the gear.

I'm going to purchase a socket tester as advised, as well as as couple of these: http://www.amazon.co.uk/Masterplug-ARCDKG-Safety-RCD-Adaptor/dp/B000RZDNZM - if my gear is at fault, these should trip before the master switch does!

As John mentions, my suspicion is the actual breaker box too, but i've found a couple of areas of water ingress and also some dodgy light wiring (although that doesn't explain why the sockets seem to trip the master), but anyway.

Thanks for all your advice!

Ed

 

[PRR]

After all that... you *could* have rats chewing your boiler insulation, and when the train goes by at 31MPH it vibrates just-right to touch and cause a 6,000 Amp fault. So the 63A Main is doing its overload job.

Just for sub-reference (and cuz I won't enter SprocketSlutz), AND because I'm debugging (rip/replace) a previous owner's electrical work, I whacked out a couple images.

To US eyes, the UK CU is strange. Sleek. Small. Horizontal. One row (in residential work). 4-12 breakers. The first image is Beatsmith's box, cropped and re-interpreted.

For several good reasons, US boxes are larger, 20-40 breakers, and vertical 2-row.

In the USA, GFI/RCB in the *main* breaker is unknown. The early GFI were much too prone to no-reason tripping. GFI is applied per circuit: early-on at specific outlets (kitchen, bath (yes, lotsa bath outlets!)), later in the fusebox for specific circuits going to dangerous locations.

In the US, GFI is required in the bath and kitchen outlets (near wet grounded plumbing) and basement garage and outdoor outlets (wet grounded concrete/dirt), and some other places (with several exemptions). There is a new requirement for AFCI but {rant omitted}.... I wire like it is 1999.

If I fully complied with code, I could catch a tingle between toaster and sink, GFI trips, I'd lose the kitchen outlets but still have kitchen lights. AND then I would know pretty-near where the problem was. (Which is not always helpful: I had nuisance-trips for a year until I figured where the previous owner did it wrong. But at least I had light to work in.)

While you "could" replace the RCB Main with a plain main, then RCB the specific "dangerous" circuits, I do NOT advise DIY breaker replacement. I say this with feeling and experience: a fair part of my fusebox troubles turn out to be poor connections by the previous owner who is a much better painter than electrician. There is a knack to getting 100% connections on large leads and lugs.

> couple of these: Safety-RCD-Adaptor
> if my gear is at fault, these should trip before the master switch does!

Go ahead, they are useful.

However they *probably* trip at the *same* leak-current as your Main RCB. (They may even be the same chip!) When you have two GFI in series, which-trips-first is uncertain. Also they can interact for more nuisance-trips than either one alone.

Another difference US versus UK: in the US we do not test our work (the Inspector may have a 3-lite tester). In the UK there is a well-established procedure for commissioning new work. The power is removed, the Neutral jumper is broken. Then a Megger-like instrument tests for ANY leakage out of L, N, or E. A full job requires disconnecting all loads. There are additional steps where some loads are connected.

 

[PRR]

Lots more red test-buttons (GFI breakers) but not on the Main.

("Spa" is just a standard-size bathtub with a pump; but obviously must be GFI-ed.)

(If you squint, you'll note that this project is half-done, ignore inconsistencies.)

 

[sodderboy]

Are those "fountain" and "bierkeller" labels on those big 500 A breakers?  Dizzang!

So the GFCI breakers eliminate the need for the local GFCI outlets?  I like that.  The locals last only 2 or so years outside, and when used with GFI plugs on hairdryers it just confuses my missus.  I just chop the plugs when the warranty is finished, but she hits the TEST button invariably. 
Mike

 

[PRR]

> GFCI breakers eliminate the need for the local GFCI outlets?  I like that.

A Long Island wire-guy like you should know these things.

The in-socket GFI is $10-$20 and as you say is prone to button abuse, splashes, and seaside dew and damp. I'm not having a LOT of problem with outside GFIs a mile from the sea (may be the boxes I use), but I'm sure they will rot.

The in-fusebox GFI is $40-$50 but is out of sight and will stay dry (until the next Sandy). They may be marginally better built (based on an actual circuit-breaker instead of a couple contacts stuffed inside an outlet).

Either will GFI-protect all downstream outlets (use the Load terminals on an outlet GFI).

In-cellar GFI means you must go downstairs to reset it. That's why I am staying with at-box GFI on the outside outlets. Multiple (long!) cables in mud trip without human risk, the GFI thinks the mud may be dying. When that happens I fold and stuff the plug/socket in a milk bottle, reset the GFI right there.

For the in-fusebox GFI breaker, know your fusebox. Same-width and ideally Same-Brand (or clearly marked as approved for your brand) (realizing that a few basic boxes have been sold under multiple brands). While a Square-D breaker "can" fit a full-size GE box, this combination has not been tested and a sharp inspector can reject it. I think Eaton uses a different bus clip and won't even fit the GE?

Special problem: for a plain breaker we take the white wire direct to the neutral bus. For a GFIC (or AFCI) the white wire _must_ go through the breaker, *then* to the neutral bus (via a hard-wire off the GFIC). Often there is only one N bus and often it's on the other side from where the GFI wants to be. There's never enuff slack in the wall to pull another foot of white wire into the box, and splicing inside fusebox is poor form.

Working inside the fusebox is DANGEROUS!!

 

[CJ]

if you want to roll your own GFI,

you need, 5-10-30 ma or fixed set point?

response time is pretty good with this circuit, no chatter or motor-boating,

1 ma detection needs a nickel toroid,

most important part of circuit is the ferrite beads on the power input, isolation of this circuit from pwr line  noise is important when you are sensing 1 ma thru a current transformer,  without the right ferrite core and the 7 turns of enamel, you get false tripping all day and night, digi key fixed value inductors do not have the bandwidth needed for this app, they are about a decade low in high end response, too much wire.

LED in B+ line saves energy, it supplies the circuit instead of ground,

NTC thermistor and cr4 after the doubler circuit is cheap 1n4148 is temp control, also important in preventing false tripping.

output is opto isolated to keep that hole plugged also, 
pilot scr mcr drags massive current thru 10 ohm sensing resistors for 1 nano second, then the big guys across the line pull in and current is shunted thru them instead of the 1/2 watt10 ohm resistors, which are cooling down a degree after the 1440 watts passed by on there way to torture the bridge and scr,

 

[mobyd]

A small aside on GFIs. My kitchen is not on a GFI (decades old wiring) but after loosing a second toaster around easter time, I fitted an inline GFI to the replacement toaster - no more blown up toasters!. Turns out everyone likes toasted hot cross buns, but hot cross buns tend to loose their raisins in the toaster, which carbonise and set up an arc between the element and the housing. Nobody sells replacement elements anymore in these days of cheap imported toasters.

 

[CJ]

we had a guy who installed electric fences in prisons, 

wanted a GFI that would tell the difference between a large jack-a-lope  brushing up along side it and getting zapped or  a human arced out and depleted causing the leakage current, this way he could set off a lightbulb in the sector #3 guard tower, wtf, over?

hardest part was getting people in the shop to touch the wire for calibration, so we hooked it up to the men's toilet seat, 

 

[The Beatsmith]

Gonna be honest - i could barely understand anything after my last post... but thanks!