RCD tripping

DXP55

DXP55

DXP55

Soldato
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Shropshire
I think I am talking about RCCB - It controles half of the consumer unit and problem is on bedroom 13a socket ring - It doesn't trip the 13a ring it self
When wife was doing the ironing last year it kept tripping RCD so rang maker and told him so they gave us a new iron- Today the new iron has tripped RCCB.
Is this massive coincedence ? (Russell Hobbs)

So looking on line it says it could be a earth leakage - This only happens with the iron -vaccum is ok and all else on bedroom ring is my PC and bedside lamps.

All the wiring was renewed 12 yrs ago along with new consumer unit - Since then there hasn't been any other problems.

So any idea please - I have a meter and can do basic testing and handle wiring ok - First thing I will check is if teminals are tight on back of socket.

Next time she irons I will get heavy weight extension lead out and plug it into a lounge ring.

As if I haven't enough problems

Note. RCCB not RCD
 
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Yes, RCD tripping means leakage to earth.

Is it a steam iron? Could be water leaking where it shouldn't - perhaps a feature of the iron, or maybe it's suceptable to overfilling?

If you know somebody with a PAT-tester that would show up a problem with the iron. Or do some continuity tests on the plug e.g. there shouldn't be any connection between the live/neutral pins and the earth pin.
 
Rang a work mate and first thing he asked was "is it a steam iron" it certainly is and the common denominator between old one and new one is the wife - going by the infrequancy of the tripping I am pretty sure it's operator error so I went through a rule of use earlier so we will see if it didn't go straight through ear to ear.
I will of course check socket tomorrow but I don't think I will find anything and I have also done a test on plug on end of iron and it showed no sign of fault between + - earth.
She also thinks showers are water tight
 
Plug a kettle into the same socket you had the iron plugged into and see if it trips, the kettle will draw as much as the iron (if not more) if it doesn't trip it's likely the iron.
 
robj20 said:
No. You don't need any power drawer to trip an RCD if a fault exists it would stay tripped and wouldn't let you turn it back on.
If it only trips when ironing, it's the iron.
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Or the iron plus the existing background leakage. I'd have suggested cumulative leakage plus dodgy iron, except the wiring is quite recent.

Old houses are a git for earth leakage/coupling leakage issues, so sometimes one device will push them over the edge despite it being only half the device's fault.
 
robj20 said:
No. You don't need any power drawer to trip an RCD if a fault exists it would stay tripped and wouldn't let you turn it back on.
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Some neutral earth faults don't exhibit sufficent leakage to cause a trip in the absence of loading, particually in TNCS installations where neutral and earth are exactly the same potential in the absensce of any load on the installation, when loading happens, voltage drop in the neutral will mean there is a slight difference in potential across the fault and leakage occurs. The loading doesn't even have to be through the same RCD, as timetimes the drop across the neutral tail can push the leakage over the tripping threshold, and certianly teh case if the boards at the end of a long submain

Gut feeling is the iron, steam irons can be a pain for it, bit of water where it shouldn't be, if the problem goes away when not ironing I would suspect this. To prove an issue with the iron, next time it trips out, unplug it and get the meter and measure on the highest resistance settings between live and earth, and also neutral and earth, you should be looking for an out of range/open circuit value, keep your fingers away from touching both probes at the same time (its not dangerous, but you could get a false reading through your skin at this scale). Anything less than 1Mohm (10^6) I'd be concerned about. Normally insulation tests are carried out at 500v (and that does teach you to keep fingers off the probes!) but for a water ingress fault, it is very likely to show up a test at much lower voltages (not guarenteed though, treat it as a test for badness, not goodness, if you see an insulation fault with a 9v test, then it'll still be bad, or worse at 500v, if you don't see one, doesn't mean for sure that there isn't one) Important to do it straight away, the water will evorporate pretty quickly and the fault will clear.

A plug in RCD won't prevent the RCD at the board tripping (they will both be 30mA), but if you are lucky they might go together, proving both saw the fault (unless its an active RCD - these automatically trip on power loss so would prove nothing)
 
Sorry Gents I am past my sell by date.
Just been out in garage in better light and stronger torch to check consumer unit that is right up in a corner and it is the RCCB that is tripping not RCD.

So what difference does this make.:o
 
I would suspect background leakage on other devices or circuit using the same RCD. Get an electrician in to test each circuit for leakage as many devices have a small amount which is unavoidable but equally a device or cabling could have a fault increasing the background leakage to near the usual 30mA trip point.

If other devices and cabling are okay but the background leakage is still too much then this can often be solved by just splitting up circuits onto separate RCD devices which is often just changing some parts in the existing consumer unit.

For example I've had 4 UPS devices for years (server rack, important PCs etc) and I know they have some leakage which all together could get close to or exceed the 30mA trip point for a single RCD. Hence in my current home I split them up onto multiple RCBO which are miniature breakers that can replace the plain on/off per circuit switches on a non RCD part of the consumer unit, and now there are only one or two UPS devices on any circuit.

I was lucky to have four ring circuits for sockets which made this easy without new cabling but most homes will have at least two where this can be done before considering other circuits for boiler/cooker/lights etc. I've also done this for a couple of other circuits so I am not far off having one RCD per circuit and this gives the benefit of a fault on one circuit not affecting the others.
 
Adam_151 said:
Gut feeling is the iron,
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yes - condensation in the iron body / water that has been poured into it inaccurately / using steam function before iron has warmed up so you get water coming through to the plate.

I've had the iron trip the rcd in the past, iron is probably 20yrs old and the ceramic material in the elements is porous if the end seals are degraded, so you can get current leakage.
(coffee machine did the same initially after it was stored in garage for a few months during move)
 
She has had a ironing session this morning -filled iron up to half way - turned on then when hot did the ironing - Drained water after turning off and so far so good.
If it can get broken-damaged -flooded- destroyed she has the qualifications to do it.
 
K.C. Leblanc said:
Probably not, they'll both be 30ma and their will probably be leakage elsewhere meaning the CU RCD will probably trip first.
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Hadn't thought of that. I had an RCD extension cord when I was doing DIY outside and it tripped when I left the tool outside and it rained a little, but left the CU RCD okay. I guess if the leakage is before the secondary RCD on the cable, it never knows and can still trip the CU.
 
moogle said:
Hadn't thought of that. I had an RCD extension cord when I was doing DIY outside and it tripped when I left the tool outside and it rained a little, but left the CU RCD okay. I guess if the leakage is before the secondary RCD on the cable, it never knows and can still trip the CU.
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Generally a secondary RCD on a socket or extension won't protect the upstream RCD from tripping, unless it's intentionally a faster or lower threshold model.
 
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