outdated GE RCBO 617706

tim taler · Mar 14, 2022

Hi all!

GE RCBO 617706
A few days ago I found this one in my junk box and need to clarify is it type A or AC?
I have tried to search for specs or something else but nothing at all.
There is a two marks under a test button, first is a typical AC but what about second?

[ElectriciansForums.net] outdated GE RCBO 617706

timhoward · Mar 15, 2022

Type A, the symbols are just next to each other.
Have you spotted it’s a C curve?

tim taler · Mar 15, 2022

timhoward said:
Type A, the symbols are just next to each other.
Have you spotted it’s a C curve?

Thanks a lot for your help! Yeahh, C, so I will keep in mind.
ummm...that icon looks similar to well-known "pulsation dc" but I'm not sure it really means type A... just an obsolete symbol?

timhoward · Mar 15, 2022

I looked into it a bit more. I did find this:

It seems to be a "Type A and a bit more", the article says:
"to provide protection in case of alternating residual sinusoidal currents up to 1 Hz , pulsating direct residual currents and smooth direct residual currents".
It's a first for me too.

Which type of residual current device (RCD) you should use for protection? | EEP

It is not quite clear when and by whom the first residual current device (RCD) was developed, but it certainly appeared on the market in the 1950s and was

electrical-engineering-portal.com

timhoward · Mar 15, 2022

Too late to edit - I think the article has a typo and what I described is irrelevant and type B. Sorry!

loz2754 · Mar 15, 2022

I have seen this symbol before and ignored it, treating the RCD as a type AC.
All the recent charts that show the various types of RCD, have a box drawn around all of the waveform shapes.
It's confusing to say the least, to have a quarter sine wave next to the box, and not inside the box.