Electrics tripping ( on going problem)

[KevinS]

Got called to a house today, they claim to be having problems with the electrics tripping.
had 2 problems, one was the immersion heater (which I think is the true cause of the problem.
the other problem I had was the RCD was tripping at 24mA on one side and 15mA on the other (ramp test)
Changed the RCD and still had exactly the same readings 24/15
also the RCD was giving me >2000 on 1/2 test.
Had me stratching my head a little till I guessed what it was
ps all cables were clear on insulation
see who guesses the correct answer 1st

 

[tony mc]

The more than 2000 is correct as it is not tripping when 15mA is injected into the circuit so it times out at 2 secs.
Are you useing a Megger by any chance!

 

[tony mc]

As far as your ramp test are concerned 24 ms is fine but the 15 is on the limit.

Where you testing with loads connected by any chance ?


Sent by my Hoover 234 talkpad

 

[KevinS]

Yes using a megger
Possibly I didn't explain clearly, I know > 2000 is correct, but i shouldn't have tripping readings of 24/15 on a ramp test if it's ok on 1/2 test,

 

[KevinS]

Load was on but nothing at all on circuits as I had just done an insulation test

 

[tony mc]

Why not as the RCD will pass the half current test !

- - - Updated - - -

What ramp test readings are you expecting!

 

[KevinS]

Well I was expecting about 22 on both sides
sorry I just realised how I now made myself clear - I am talking about tripping current not tripping times. The RCD is tripping at 15mA

 

[telectrix]

i don't understand what you mean by7 both sides. a ramp test gives 1 reading.

 

[KevinS]

You do a test at 0 degrees and 180
so I was getting 24 on 0 degrees
and 15 on 180 degrees

 

[tony mc]

Kevin what model Megger are you useing if its the 1550 range you can't Ramp test on both sides of the waveform on AC.

Your not on the DC mode by any chance?

Had me stratching my head a little till I guessed what it was
ps all cables were clear on insulation
see who guesses the correct answer 1st

You will have to tell us the answer because I am a little confused don't know about Tel mind you.


Regards

Tony

 

[sedgy34]

Get a better tester?

 

[Spazz]

I had this on my Mertial Tester the other day - had the wrong wave set on my tester.

Changed the wave over and all working fine now