Reading on 30ma trip too high

[vbyrne]

Hello, I have completed a test on a flat ,everything was fine until I got to the RCD test. The set up is T-N-CS ,6 circuits on the main switch side of the board and four on the trip side .I,m using a Fluke tester and have recently got it calibrated ,when I do x1/2 it,s ok ,when I do x1 it reads 246ms , and when I do x5 its ok .I have put 3 square D trips into the board and the readings all come up the same ,so it must be something on the board some where that is causing this high reading , any help lads:whatchutalkingabout:bigcry:

 

[ExArmy]

weird. have you tried your tester in on another board?

 

[malcolmsanford]

Have you read appendix 3 Table 3A page 243 of the BS 7671-2008??

 

[IQ Electrical]

Hello, I have completed a test on a flat ,everything was fine until I got to the RCD test. The set up is T-N-CS ,6 circuits on the main switch side of the board and four on the trip side .I,m using a Fluke tester and have recently got it calibrated ,when I do x1/2 it,s ok ,when I do x1 it reads 246ms , and when I do x5 its ok .I have put 3 square D trips into the board and the readings all come up the same ,so it must be something on the board some where that is causing this high reading , any help lads:whatchutalkingabout:bigcry:

If your RCD is to BS EN 61008 then it must trip at 1X within 300ms.

 

[telectrix]

have you tried testing it with no circuits connected?

 

[truckster]

Did you test at the board or at a socket? Theres a post on here some where that speaks of rcd's giving funny results if you test at the board, try it at a nearby socket. Are both sides of the wave giving the same reading?

 

[High Tower]

Take all of the loads off and test at the bottom of the RCD, my 1653b doesent like doing 1x if the rcd is under load

 

[vbyrne]

Thanks for that lads I,ll try all of the idea's posted until I get it sorted ,I'll let you all know how I got on.

 

[tony mc]

Not sure how the Fluke tester works but does it not give you the trip times on all the tests seems odd that OK is displayed how does it know what RCD type it is BS or BSEN ?

 

[Deleted member 26818]

Am I missing something here?
It trips at 246ms, but is supposed to trip within 300ms.
What is the problem?

 

[IQ Electrical]

Am I missing something here?It trips at 246ms, but is supposed to trip within 300ms.What is the problem?

That's the point I made in post 4, assuming the device is to BS EN 61008/61009.

 

[Octopus]

Am I missing something here?
It trips at 246ms, but is supposed to trip within 300ms.
What is the problem?

I think that many people think that the 40ms applies to 1x!

 

[telectrix]

i would not be happy with 264mS, same as a IR of 2-3 M ohms on a circuit. bit borderline for my liking.

 

[IQ Electrical]

i would not be happy with 264mS, same as a IR of 2-3 M ohms on a circuit. bit borderline for my liking.

No, look at the units you are working with!

You're talking about 0.26 seconds disconnection and an IR value of 3 million Ohms, you can be happy!

 

[telectrix]

i.m not saying i'd be too fussed. just that when a reading is close to the limit i like to try and find out why. combination of old age and paranoia