300mA R.C.D.

welshmadness · May 3, 2009

Hi guys.
Installed a 63A 300mA R.C.D. on site as the eli was 5.2 ohms. (3phase tt system at a pumping station).
Anyway, when it came to the trip times, i did not get a trip at 1* current, only at 5*.(17.8ms) Is this right?
Also, what are the max tripping times for a 300mA R.C.D.?

Thanks in advance.

electro · May 4, 2009

Hi

No its not Ok it should trip on 1 times the operating current, try a ramp test, to test the mA tripping current of the RCD.

Allow up to 200ms for 1 times (300mA) and 40ms for 5 times (1500mA), these are maximum operating times.

regards

welshmadness · May 7, 2009

Hi electro, tried the ramp test and no trip. Got a replacement unit on order so will see what happens when i fit that one.

Cheers

old dog · May 7, 2009

i am sure someone will correct me if i am wrong
you do not do a 5 times test on a 300mA rcd i wiil double check later

trebor · May 7, 2009

Absolutely correct Old Dog RCD`s up to 30ma are the only ones that are used for additional shock protection and need to operate in max 40ms at 5 times operating current.

Also the 1 times test is max 300ms for BSEN61008 and 200ms for BS4293 devices, general purposde in both cases

electro · May 7, 2009

old dog said:
i am sure someone will correct me if i am wrong
you do not do a 5 times test on a 300mA rcd i wiil double check later

Hi olddog

Please read my quote no one has suggested to do a 5 x test, I suggested to a ramp test this is in no way a 5 x test, its a test of the minimum tripping current (a steady current until the unit trips). The tripping times are as per 17th edition the 5 times was to show you were the 1500mA fault current came from and expected time you should expect the unit to trip if you applied certain currents.

Hope this helps.

regards

old dog · May 8, 2009

hi electro i must be reading the op wrong

i did not get 1* only at 5*

i took that to mean he tested at 5x

slocm3105 · May 9, 2009

trebor said:
Absolutely correct Old Dog RCD`s up to 30ma are the only ones that are used for additional shock protection and need to operate in max 40ms at 5 times operating current.

Also the 1 times test is max 300ms for BSEN61008 and 200ms for BS4293 devices, general purposde in both cases

I also believe that for BSEN 61009 it is 200ms

.