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Discuss Name this device in the UK Electrical Forum area at ElectriciansForums.net
If Murdoch is fitting a modern plastic CU with 30mA RCD’s is there a need for a front end E/L unit? Just use it as an isolator. Makes the job safer as there’s no playing about with live tails or dare I say interfering with the service head. (I’ll go and get the carbolic mouth wash now).
I’ve only done this once, I super glued the test button and painted it and the label black with the wife’s black nail polish. SHMBO wasn’t happy though.
This is all before my time - a voltage-based RCD of sorts?
Were 'proper' RCD's too complicated/expensive to manufacture back then? Or not even invented?
These were used as isolation switches by that world renowned bathroom company Dolphin
If you have ever opened up a original Dolphin shower,the sneaky lads at Dolphin design pinched these breakers to use as isolation switches for their showers
Would you believe they had a fancy looking piece of string linked to the elcb which was mounted side ways on and a glass front to hide the dirty deed
Thanks Tim & PC!!It looks like it.
Also something to have checked professionally to see if you have adequate protection for the installation as a whole since VOELCB have a number of issues, one being they are generally old and may not be tested (have you test tripped it?) and the other being that any additional earth bonding can make them ineffective at detecting a fault.
The other worrying sign is the apparent shuffling of phases!
It might be that device is now largely redundant if the distribution boards have RCDs in them providing the required level of protection, but I certainly would suggest it is checked. Do you have photos of the board(s) the device is feeding?
It sounds like it, though of course enough accumulated leakage might trip a RCD-like device (though on 3P a lot of the would cancel so really it would be imbalance on leakage).The device feeds a 3P 63A switch fuse next door to it, then a long run of armoured cable to a modern 3P board, with RCBOs. Apparently the device is tripping once in a blue moon when there is a lot of load on. Sounds like from what timhoward says, it may be overload rather than leakage that trips it?. Sadly the plate is no longer there.
Thanks PC! Yes, it's TT. I was thinking 300mA type S. So much hanging off it, 100mA could nuisance trip, even with everything on 30mA RBCOs. I think they left this in as they did not want to mess with the meter tails...It sounds like it, though of course enough accumulated leakage might trip a RCD-like device (though on 3P a lot of the would cancel so really it would be imbalance on leakage).
If it were my business I would look at replacing it with a 100mA or 300mA delay RCD in a suitable enclosure.
back in the 70's, with BT it was Subscriber Trunk Dialling.STD stands for Short Time Delay.
I believe that is a 3 phase earth leakage circuit breaker with overload protection. A kind of primitive RCBO with different leakage detection method, relying on a coil between real earth and installation earth.
Under the stickers there once would have been a plate that told you exactly what it is. See example of another one below.
I'm sure you already know that it needs taking out of service. And as the stickers read like a list of special locations with special requirements this one may need more than a little thought.
View attachment 94275
View attachment 94276
If you remove it, save it, as collectors might like it!
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