Chilton VCCB

[Onoff]

I've not seen one of these voltage controlled circuit breakers for a few years!

Tbh I'm surprised the DNO fitted a new head and meter with it there.

There's a bit of T&E coming out the bottom of the VCCB feeding a rusty, lidless ancient cu, the other side of the wall.

 

[Martin-Sy]

I have a vague memory of being told about them but I've never seen one.
There's a nice description here:

David Savery Electrical Services Ltd. - The Voltage Operated Earth Leakage Circuit Breaker

Why the Voltage Operated Earth Leakage Circuit Breaker fell out of favour

www.dses.co.uk

 

[sparkysy]

I've never come across one that I haven't removed and changed for either a 2pole main switch or RCD in the case of TT supplies!
They never worked properly anyway due to parallel earth paths especially when incoming services e.g. water & gas were piped in metal and if you were unfortunate enough to be outside then it ain't going to work in fault conditions as you will be the earth path for the fault current! Lovely!
I hope you said to them to get it looked at?!
Sy

 

[brightspark]

jesus christ wonderfull things voltage operated the earth rods crap and the connection is coroded and they dont work farmers used to love them having dodgy wiring ive seen pigs get electrocuted and cattle getting milked jumping up and down when they tried resetting them

 

[Onoff]

or RCD in the case of TT supplies

I believe it is a TT supply. Comes in overhead and that green (not green and yellow) single core shoots off, is joined to a black wire that disappears into the concrete. Guessing there's a buried rod.

Funnily enough @brightspark it is an ex piggery!

They want to feed a new annexe and have already run a 16mm2, 2-core SWA in a duct underground. A yellow duct no less! I'm not sure if that's worse than the usually used / seen blue! Too late now to give them any tape for the trench as it's all concreted over.

I was thinking they should go Henleys after the meter. Then one set of tails to the local cu the other side of the wall. That's a whole other story, falling apart, rusty and I think everything run in VIR.

Another set of tails to a 100mA time delay RCD then an 80A switch fuse feeding the SWA to the annexe. They've a BG split board for the annexe.

As it is it's actually better than many round here. All farms or ex smallholdings.

 

[500e]

VIR Not seen any of that for very long time.

 

[Onoff]

I swear this is true. Farmers workshop kept tripping the house RCD. I had a look. The "cable" was an extension lead across the ground that ran under the log pile. The sheath was damaged and cores exposed. I explained about IR and how damp gets in and lowers resistance etc. Off he went and came back with a can of Damp Start. Squirt, squirt and the IR increased!

Same place the earth cable is attached to the "rod", in fact a scaffold pole, with a pair of rusty mole grips.

 

[Onoff]

I love people who do something then ask for help. They always show you and say "That'll be alright won't it?"

Another one had a new gas boiler put in, in his loft. "I used the old immersion supply and rubbed the letters off the switch!" he said.....

16A breaker feeding the single socket in the airing cupboard. He'd replaced it with a 45A DP cooker switched and sanded off the words "COOKER". From there to the boiler.

 

[Onoff]

Then there was the ring main in 5-core flex...

 

[Onoff]

Most farmers have a bit of an "always against the clock" mentality imo. If it's going to turn bad weather you have to get that whatever fixed asap there and then. Function over form etc. Get it welded, get it cut. There's no time to faff making it pretty. Then there's the "I got it for nothing / already had it, so am using it!" All SWA around here is known as "shed cable". The CSA doesn't matter seemingly. It's "black" and it's got that "wire stuff round it". Job's a good 'un!

 

[sparkysy]

Things like that do happen especially when it's an emergency and must be working again now!
But I have seen a real change in the mentality of the younger generation of farmers for the better!
Most of the work I do is agricultural installation and yes I have seen most bodges known to man and beast, but in the last 10 years or so more often than not they want a safe and compliant installation that will not need fixing every year.
Take for instance the farm we rent at, it had 2.5mm 2 core swa feeding the grain store from a 63a MCB (TT system) then 2.5 twin and earth radial circuits on a 32a fuse lashed around the metal perling's with no clips nothing, and was nibbled in so many places by the wildlife it was a bit on the dangerous side to say the least.
Our old landlord who was an absolute gentleman sadly passed away. His grandson now farms it and has had me replace nearly all the farm wiring and distribution, with a safe and compliant system!
So the trend is changing!
Also now for a lot of the farm assurance and insurance they require an up to date electrical installation condition report.
It can only be a good thing!
Sy

 

[brightspark]

still see a few crabtree black voltage operated trips about and old wiring.i just tell em to get rewired for safety and it wont be me doing it i select my jobs and dont work on krap

 

[Erie Fred]

Shall I mail you one of our panels ?

I was just in Home Depot Sunday, and a 200 amp main panel with 40 slots was only $200
or so......

 

[Onoff]

Shall I mail you one of our panels ?

I was just in Home Depot Sunday, and a 200 amp main panel with 40 slots was only $200
or so......

Odd how what we call consumer units are referred to there. Then the 200A reference, alien to us at least in a domestic setting. We might have a board with a 100A incoming switch but tbh that's so standard it's not even referred to regarding the board.

A "split load" board is common where you have a couple of GFIs (what we call RCDs) feeding half a dozen breakers each. Still a case of a ground fault on one circuit will take out that bank of circuit breakers.

The preference here now is for "all RCBO" (residual current breaker with overload) boards that minimise inconvenience and make tracking faults and testing easier. Basically each circuit has its own combined circuit breaker and RCD (GFI) in one compact unit. This for example shows a line of RCBOs, then a 100A main switch. On the far right is a surge protector. This particular brand is double pole so switches line and neutral in the event of a fault.

(My son did the 3D printed prototypes for the blanks on the left as an aside and provided the files that then went into production).

 

[Onoff]

Fused switches. The smaller ones I think limit you to supply in at the bottom and load at the top:

Whereas the big long metal cased ones are configurable for in/out either way.

What's the smallest fused switch you can get that will take the supply in at the top would anyone know?

Cheers

 

[brightspark]

ive only realy ever seen and fitted the 2 switchfuses that you show .are u fitting mains tails top and bottom

 

[Onoff]

ive only realy ever seen and fitted the 2 switchfuses that you show .are u fitting mains tails top and bottom

I'm not fitting anything just trying to point the chap in the right direction.

He has to feed a 2-core 16mm2 SWA from the switch fuse, ideally out of the bottom.

The small ones don't really lend themselves to terminating SWA. From memory one make you can get like an adapter / short trunking piece with knockouts that goes on the top side / supply but that's for say T&E.

 

[brightspark]

I'm not fitting anything just trying to point the chap in the right direction.

He has to feed a 2-core 16mm2 SWA from the switch fuse, ideally out of the bottom.

The small ones don't really lend themselves to terminating SWA. From memory one make you can get like an adapter / short trunking piece with knockouts that goes on the top side / supply but that's for say T&E.

what you can do is fit a 4x4 adaptable metal box and fit below or above the switchfuse . strip the the armoured back leaving just long tails fit the armoured gland to the box and the tails just pass through the box using a a brass coupling and direct in to the isolator . you can get 25mm in no bother

 

[Hotstuff]

Funnily enough @brightspark it is an ex piggery!

They want to feed a new annexe and have already run a 16mm2, 2-core SWA in a duct underground. A yellow duct no less! I'm not sure if that's worse than the usually used / seen blue! Too late now to give them any tape for the trench as it's all concreted over.

I was thinking they should go Henleys after the meter. Then one set of tails to the local cu the other side of the wall. That's a whole other story, falling apart, rusty and I think everything run in VIR.

Another set of tails to a 100mA time delay RCD then an 80A switch fuse feeding the SWA to the annexe. They've a BG split board for the annexe.

As it is it's actually better than many round here. All farms or ex smallholdings.

Hi Onoff. The only thing I would throw into the mix would be the cable conductor cross section and is the SWA cable sheath cross section sufficient for a sub-main?

Those old Voltage operated trips were horrible things and I doubt many that had been installed were ever tested for compliance.

 

[Onoff]

Hi Onoff. The only thing I would throw into the mix would be the cable conductor cross section and is the SWA cable sheath cross section sufficient for a sub-main?

Those old Voltage operated trips were horrible things and I doubt many that had been installed were ever tested for compliance.

The incoming supply is I think TT. It's rodded adjacent to the meter box. There are no PME stickers to suggest it's been "upgraded" as many have round here.

My thought was the switch fuse to protect the SWA then rod the new cu in the annexe too.

I'm a bit rusty but looking in the BBB table 54.7 then I think the formula is (k1/k2) x S.

k1 = 115 from Table 43.1
k2 = 51 from Table 54.4
S = 16, the CSA of the line conductor.

Calculates as 36.

So the CSA of the steel wire armoured needs to be greater than 36mm2.

CSA of 16mm2 2-core armoured is 46mm2.