Is this a TT system ?

[rompling]

Hi have to move a dis board and upgrade with new but confused a little bit
Its in a urban area a 1920`s semi detached house but cant see any overhead lines at all
I looked at the old school ELCB and thought TT , the main supply cable looks like old VR cable which is neatly clipped all round the house at high level , then looks to go in the other house joined to it down to there supply intake ( couldnt get access to look inside but cant see any overhead lines going to this house either


I looked in the dis board`s believing a 10 mm went out to the earth rod but that went to the water and in the other one to the gas but no earth from either board to an earth rod /stake/pit

Any help appreciated

 

[MDJ]

1960s was usually voltage trips

 

[Engineer54]

1960s was usually voltage trips

And they only really came into the general market place in the late early to middle 60's, which is why i'm not yet convinced of the photo being an early RCCD which came much later...

 

[itselectric]

I would lay my next wages on it eng. but I'm retired lol.
I installed plenty of these in their early days.
The main switch was a voleb, and Crabtree added a toroidal coil with tails going through it.
There is no fuse under that cover just the Voleb and coil which converted it to RCD

I even remember the first one I installed, did my checks, installed it and every thing was fine until the immersion was switched on, then it tripped.
on checking the immersion I found that a couple of strands of flex on the neutral were touching earth.
The voleb I took out wasn't tripping, this was my baptism on RCD'S.

 

[Engineer54]

I'll bow to your knowldge then, but it must have been a bit later than the late 60's though. The VOLB's were around a good few years before the RCCD's started replacing them....

 

[itselectric]

The Germans were using rcd type breakers in some of their machines in late 50's.
I am a little long in the tooth so it could have been very earl seventies when I used my first one.
but no later than 1971.
If op is going bck to job can you get some pics of unit with cover off and if you look on the side of the cover there will be a label with unit details.

 

[Engineer54]

I'll not argue with you, but during my time in industry, our company used loads of German made machinery in fact most of the American machinery was being replaced by German stuff. None that i can think of, had any form of RCD protection incorporated. Anyway were talking about up front installation earth fault protection, and i can't remember seeing RCCD's on domestic installations until late 70's early 80's.


But like you, i'm a bit long in the tooth to be absolutely certain about obscure dates, so let's just say it was a bloody long time ago. ...lol!!