CU Change today - anyone familiar with these ?

[Dave OCD]

Did an easy CU change today, the only things of note were there was only one RFC and in the old Wylex each leg was connected to its own 30 amp fuse ! The place was built in 1964 so probably been like that for 50 years ?
The other unusual [to me] thing was a '2 part' Crabtree trip switch with a separate big coil unit - no actual connection from the board to a 'field' terminal as you would find in a traditional voltage trip either, so I'm wondering if this was a very early RCD ?
A couple of before and after pics are attached to peruse....

 

[davesparks]

I've not seen that before, have you still got the parts? That's the kind of thing Lucien would likely want for his museum

 

[Dave OCD]

Yes I saved them Dave, the left hand part was exactly like the old Crabtree Voltage trip but without the test button which was on the coil unit. It could well be a very early RCD but probably known as a 'current trip' or something like that back then.

 

[davesparks]

You will probably find that it is a voltage operated trip which has been adapted by the manufacturer to operate on current by adding the coil.
There is a very similar device I have come across in the past where that trip and coil are housed in one enclosure but still two distinct parts when you look inside

 

[uksparks]

I'm sure I've seen one the same before, I did take a photo, I'll see if I can find it.

you know those blanks, do you like them? I generally speaking always fill up all the ways with breakers to avoid using blanks, either that or use proper blanks that fit on the din rail.

 

[Risteard]

I generally speaking always fill up all the ways with breakers to avoid using blanks

I hate circuit breakers which don't do anything filling up a board. Pet hate.

 

[HandySparks]

Is that a 1A rated tripping current? (Can't quite read it clearly.)

 

[Leesparkykent]

I hate circuit breakers which don't do anything filling up a board. Pet hate.

Same here and when they write spare......:banghead:

 

[Dave OCD]

I'm sure I've seen one the same before, I did take a photo, I'll see if I can find it.

you know those blanks, do you like them? I generally speaking always fill up all the ways with breakers to avoid using blanks, either that or use proper blanks that fit on the din rail.

I don't mind that type of blank to be honest, I don't like leaving unused MCBs in the board though as invariably someone switches them on which an cause confusion and also look like I haven't labelled properly ! I left the spare MCBs with the customer as there's a lot more work to be done there over the coming months.

 

[Dave OCD]

I hate circuit breakers which don't do anything filling up a board. Pet hate.

Me too , and even worse when people write 'spare' on the unused labels !

 

[Andy78]

Ha! I put unused mcbs in a db the other day when I ran out of din rail blanks. It didn't feel right, even though I have literally a bucketful of new mcbs going spare.

 

[Dave OCD]

Lee ! You beat me to it again !

 

[Dave OCD]

Is that a 1A rated tripping current? (Can't quite read it clearly.)

Yes that's what it says which I thought was strange - but on the big coil unit it also says 'min tripping current 35 ma '. Interesting to come across something unusual like that - well unusual to me anyway.

 

[ImpededLoop]

Interesting find there, I've not seen one before like that.

Out of interest, what was the earthing arrangement (TT, TNS, TNCS)?

 

[Dave OCD]

It was TT, mind you having run in a new 16mm earth & new rod and cover box I noticed a small label on the meter board which said 'PME AVAILABLE ON REQUEST' :lol: