RCBO fault finding

[jase31]

My dewalt battery charger (double insulated) is tripping the RCBO. Other appliances seem to be fine. I have tried the charger in other properties and it does not trip.

What tests can I make on a multimeter on the charger and/or wiring to help identify the fault.

 

[nickblake]

Cant realy carry out any tests using a multi meter , you realy need a portable appliance tester that can carry out insulation load and earth leakage tests , only this type of equipment will give you the readings and tests you require , and if its not the equipment thats faulty then you need an installation tester to carry out insulation tests RCD trip times and Ramp tests these are not tests you can carry out on a multi meter

sorry cant be of any more help

Nick

 

[Guest 004]

Insulation resistance

 

[telectrix]

or buy a makita.

 

[mayfair]

Just a thought i cant get to involved as outside UK regs for to long. But when someone asks a Q like this instead of just for example putting IR test could we not take the time of how to explain how to and the readings that should be expected could help some of the members that are a bit short on practical experience.

 

[jase31]

Could it be a fault on the wiring in the house, rather than the charger?

 

[topquark]

Yes it could be a wiring fault, it could be a combination of things. Either way, your battery charger seems to have an earth leakage issue. IR testing will give you an indication of how bad it is. But you should really check the amount of current leakage to earth and if it's more than about 5 milliamps, you'll want to know why. It may have some leakage as it's a charger, so it's power supply will be "dumping" some current down the earth line when smoothing and converting the AC to DC.

 

[Engineer54]

Don't think you'll find an earth lead on these drill chargers, there class 2 normally!!

 

[topquark]

Don't think you'll find an earth lead on these drill chargers, there class 2 normally!!

Won't be much earth leakage then PMSL, back to the wine methinks!

 

[Hawk81]

Yes it could be a wiring fault, it could be a combination of things. Either way, your battery charger seems to have an earth leakage issue. IR testing will give you an indication of how bad it is. But you should really check the amount of current leakage to earth and if it's more than about 5 milliamps, you'll want to know why. It may have some leakage as it's a charger, so it's power supply will be "dumping" some current down the earth line when smoothing and converting the AC to DC.

He has already stated that the charger is double insulated. It more than likely has a 2 core lead on it. Very unlikely it has any earth leakage.

E54 beat me to it!

 

[nickblake]

Just a thought i cant get to involved as outside UK regs for to long. But when someone asks a Q like this instead of just for example putting IR test could we not take the time of how to explain how to and the readings that should be expected could help some of the members that are a bit short on practical experience.

Fair Comment mayfair :Jase31 , the chances are its not an insulation problem this is due to the fact its class 2 very rare to get a problem like that, not impossible mind , when in my first post i point out the tester you needed the PAT tester was to check the appliance reaings IR should be around >200 ohms anythin less than 2 ohms then you could get problems , the RCBO ramp tests should be below 30ma if the RCBO is a 30 ma tripping time ,to find this out you then need an RCD tester this will test the RCBO for correct operation normally the RCBO's will trip around 24ma but i have seen some very over sensitive ones tripping at less than 2ma , so this is what you should be looking for ,you should also test the RCBO tripping times to ,what could cause the problem is leakage of your charger circuits causing an inbalance of the RCBO this could then cause the rcbo to trip , so the tests would reveal that , unfortunatly as i have mentioned in a previouse post you will be unable to carry out these tests with a multi meter , so it maybe an idea to see if you can find some one to either test you charger using a pat tester and even the RCBO to see if thats faulty ,any more advise just ask mate

mayfair if my post sounds as im having ago please be assured im not i 100% agree with your comment so thought i'd add a little more to my original post

Nick

 

[topquark]

Not unless it has a VERY dodgy plug

 

[Deleted member 9648]

The charger has a 2 core lead...no cpc.....the only possible place where earth leakage can occur is the plug. Not unknown if the plug is damaged and /or dirty,check it and replace if it looks suspect.

 

[mayfair]

Thats the sort of info we should be giving Great post Nick, Its difficult for me to Answer some of these members as I have been in Spain for 21 years and dont want to get someone into trouble.

Fair Comment mayfair :Jase31 , the chances are its not an insulation problem this is due to the fact its class 2 very rare to get a problem like that, not impossible mind , when in my first post i point out the tester you needed the PAT tester was to check the appliance reaings IR should be around >200 ohms anythin less than 2 ohms then you could get problems , the RCBO ramp tests should be below 30ma if the RCBO is a 30 ma tripping time ,to find this out you then need an RCD tester this will test the RCBO for correct operation normally the RCBO's will trip around 24ma but i have seen some very over sensitive ones tripping at less than 2ma , so this is what you should be looking for ,you should also test the RCBO tripping times to ,what could cause the problem is leakage of your charger circuits causing an inbalance of the RCBO this could then cause the rcbo to trip , so the tests would reveal that , unfortunatly as i have mentioned in a previouse post you will be unable to carry out these tests with a multi meter , so it maybe an idea to see if you can find some one to either test you charger using a pat tester and even the RCBO to see if thats faulty ,any more advise just ask mate

mayfair if my post sounds as im having ago please be assured im not i 100% agree with your comment so thought i'd add a little more to my original post

Nick

 

[MarkieSparkie]

Does the bare charger (minus battery) trip the RCBO? Or does this happen when a battery is plugged in for charging? Have you removed (temporarily) ALL other loads from the circuit protected by the RCBO, whilst attempting to use the charger?

 

[Des 56]

A few posts seem to concentrate on the rcbo tripping because of earth leakage,its a class 2 appliance, so it seems very unlikely

Have you considered that the tripping may be the overcurrent part of the Rcbo
Perhaps a few of the primary windings are shorted and its exceeding the rating of the mcb part of the Rcbo

 

[kenny james]

instead of jumping on the band wagon of earth leakage faults which as mentioned it is a class 2 equipment so this shouldnt be in the equation he does mention he has an rcbo installed this can also detect an overload too. this happened to me on an ordinary mcb type b. the fault was the battery of the drill have you a spare battery pack to test!!. hope this helps.

 

[Deleted member 9648]

While it may be a class 2 appliance the plug has an earth pin and if there is dirt/grease in the plug and perhaps a crack or damage to the plug I have known them trip RCD's. Another occasional cause is the cardboard info template that some pugs have on their base when new.....these often get left on and if they get damp enough leakage can occur to trip an RCD....That was the point I made in a previous post,if it is the RCD part tripping it cant be the appliance,it must be the plug......
An overload issue is possible but it seems unlikely that a charger would make much difference,they are only a few watts,unless it is faulty,in which case you would expect it to take out the plug fuse (3a?) rather than a (32a?) mcb.