UK RCD/ combined afdd breakers

[Razzle12]

Hi can someone tell me whether I need to record the trip times on x1 or x5 on this combined device,as I'm getting trip times of 44/45 ms x1 and sometimes a lot lower ie 29 ms.This device is the sole means of isolation.
Cheers

 

[timhoward]

If the 30ma device is for additional protection bottom line is you need both the x5 tests to be less than 40ms, record the highest of the two x5 readings. (EDIT if you only have space for one reading)
The two x0.5 tests (no trip) and two x1 tests ( < 300ms ) still need checking of course.

 

[Rockingit]

You're recording the characeristics of the RCD element of the device, nothing else, so you're recording both. And if your times are <300mS on 1x and <40mS on 5x then you're all good. One thing that's changing is that the newer type A / B / F RCD's tend to have longer times than the AC types we're all used to, but perfectly acceptable.

 

[Razzle12]

If the 30ma device is for additional protection bottom line is you need both the x5 tests to be less than 40ms, record the highest of the two x5 readings. (EDIT if you only have space for one reading)
The two x0.5 tests (no trip) and two x1 tests ( < 300ms ) still need checking of course.

Hi Tim
Cheers for that ,but the device is a combined RCD/afd and is designed for fault protection,and not additional protection,so guess it's the highest x1 value of both sides of the wave .

 

[snowhead]

Is it;
RCBO / AFDD or
RCD / AFDD ?

 

[Razzle12]

You're recording the characeristics of the RCD element of the device, nothing else, so you're recording both. And if your times are <300mS on 1x and <40mS on 5x then you're all good. One thing that's changing is that the newer type A / B / F RCD's tend to have longer times than the AC types we're all used to, but perfectly acceptable.

Hi tim
Thank you very much ,is there a reg No that determines those values please .
Regards

 

[Razzle12]

Is it;
RCBO / AFDD or
RCD / AFDD ?

Hi they are RCD/AFD devices

 

[Rockingit]

The pedant in me needs to point out that the device is the device (in this case a combined RCBO & AFD) - it has no say in how it gets deployed and doesn’t know what level of protection it’s been put into circuit for. Ergo, you test it the same as any other device - RCD times and compliance (on the circuit) for ADS times.

 

[UNG]

Hi can someone tell me whether I need to record the trip times on x1 or x5 on this combined device,as I'm getting trip times of 44/45 ms x1 and sometimes a lot lower ie 29 ms.This device is the sole means of isolation.
Cheers

What test current are you applying for the 5x test as some of the newer breakers are designed to operate at a higher trip current of 250ma and not the usual 150ma

 

[Razzle12]

What test current are you applying for the 5x test as some of the newer breakers are designed to operate at a higher trip current of 250ma and not the usual 150ma

30mA trip test current
Regards