rcd waveform.

[new spark]

Hello. Please could anyone point out what exactly we are testing when we test rcd trip times at 0 degrees and 180 degrees.
(either side of the cycle.)
i will read the comments later as i have to pop out. So apologies for not replying. many thanks in advance

 

[telectrix]

you are testing the RCD on both halves of the sine wave of the 50Hz. supply.

 

[Plonker 3]

Give us what you think is the reason first. The we will gladly help you with your homework when you get back.

 

[new spark]

Thanks telectrix. Makes sense.
Believe it of not billb i wasnt taught this at college. Maybe its in the 2391 sylabus.

 

[Engineer54]

Thanks telectrix. Makes sense.
Believe it of not billb i wasnt taught this at college. Maybe its in the 2391 sylabus.

Collage or training centre??

 

[Darkwood]

yep as above for RCD to meet requirements they have to be effective on both halfs of the waveform... consider a fault occured on the negative cycle and the rcd could only see or react in time on the positive cycle then the tripping time could be so that it fails to meet requirements.depending on where on the the negative cycle the fault occured