Mineral Insulated Cable

[UNG]

moving and messing with the glands can lead to their demise even when handled carefully, in this situe i would gut the fuseboard, fit a dinrail and use din connectors to extend circuits, stripping lid off old Dist Board and making new lid possibly plastic and tap and turn 4 lid screws, mark up as necessary then from there your options are straight forward (space permitting).

The MI that can cause problems is the old aluminium sheathed ALCUMIC stuff and is best left alone or ripped out as it's difficult to do anything with it


I've done quite a few board changes where MICC was installed without any problems all that is required is a bit of care and a good understanding of what you are working with. From the pictures posted I can't see any reason for retaining the old CU as a junction box when a nice new metalclad CU could sit in it's place with a little bit of care.
The big problem as I see it is finding a spark that can work with MICC as I don't think there are many in the domestic sector

 

[Bogeybaiter]

Was given a little pocket book in my apprentice days all about MICC (Pyro) written by the company. They stated that the lifespan of Pyro was indefinate but recomend replacing the neoprene sleeving every 30-35 years!
Stunning stuff once you get the hang of working with it

 

[lamb]

I would get those pyro glands made off into 2x2 galv trunking. Because of their age they will not have earth tail pots, so if terminated onto a C/U you would need to clean the paint off for a good connection and would become a nightmare,
Then just plonk whatever fusebox you want on top of the trunking, nut and bolt an earth to the trunking for the pyros. Easy.

 

[Engineer54]

I would get those pyro glands made off into 2x2 galv trunking. Because of their age they will not have earth tail pots, so if terminated onto a C/U you would need to clean the paint off for a good connection and would become a nightmare,
Then just plonk whatever fusebox you want on top of the trunking, nut and bolt an earth to the trunking for the pyros. Easy.

Create your own earth tails with piranha nuts, you don't have to go to the lengths you suggest to change this old CU. Just needs a little thought and a little extra care and this upgrade should be no-problem at all for an experienced electrician....

 

[Big n Daft]

Pyro. Best cable ever, period.
Belt it wi' 'ommer and see how much wallop it takes before it goes down.
Replacing this DB with a metalclad CU shouldnt be a problem, I'm with Engie on this one........... again

 

[oldtimer]

An MICC installation shouldn't need rewiring if in good condition, it'll outlast you in all probability!! ..lol!!

As for the CU, yes that would be a good idea. If you can post a photo or 2 of your CU, preferably with the front cover off, ....it will help us to advise you on your best course of action.

Yep totally agree my house was built in the 50s and the lights are wired in MICC and are sound as a pound

 

[supasparxs]

looking at the pictures, I would suggest that you have a CU upgrade.
I WOULD NOT DISTURB THE EXISTING MICC CABLES

The old cables maybe brittle and moving the cable may cause them to fracture, or even the pots and seals could come loose.
The way I would handle this installation is to get some DIN rail and Klipon terminals and basically use the existing CU as a Junction box.
Then use a suitable sized piece of steel to create a lid.
then via some suitable containment link to a new CU, using singles cables.

like the guys have said above, get someone to carryout these works who are at least in there 40's and have worked with Pyro in the past

If all the circuits are all wired in MICC cable I would say that you do not need to install RCD's or RCBO's.

(personally I haven't used Pyro since 1999,)

Richard

 

[Engineer54]

looking at the pictures, I would suggest that you have a CU upgrade.
I WOULD NOT DISTURB THE EXISTING MICC CABLES

The old cables maybe brittle and moving the cable may cause them to fracture, or even the pots and seals could come loose.
The way I would handle this installation is to get some DIN rail and Klipon terminals and basically use the existing CU as a Junction box.
Then use a suitable sized piece of steel to create a lid.
then via some suitable containment link to a new CU, using singles cables.

like the guys have said above, get someone to carryout these works who are at least in there 40's and have worked with Pyro in the past

If all the circuits are all wired in MICC cable I would say that you do not need to install RCD's or RCBO's.

(personally I haven't used Pyro since 1999,)

Richard

Absolute crap!! Since when does copper become brittle with age?? Why would a pot fall off?? Any electrician that has a knowledge of working MICC cable, would have no trouble retro fitting a new CU in the present CU's position.... End of!!!

 

[oldtimer]

Absolute crap!! Since when does copper become brittle with age?? Why would a pot fall off?? Any electrician that has a knowledge of working MICC cable, would have no trouble retro fitting a new CU in the present CU's position.... End of!!!

Yes i have to agree here the only thing that gets brittle is the shroud insulation and this can happen because you can size down MICC or in other words you can use 1.5 to do the same job as 2.5 my whole house was wired in MICC I had to strip out the power but left the lights in because they were sound and not boasting but yep I did a lot of MICC years ago and my old Dad who was a blacksmith made me 2 T bars that everyone was trying to borrow as they had to use a big screwdriver aye it was like trying o open a tin of sardines stripping MICC and the biggest I did was 25mm 4 core with a 4 metre tail it was like 25mm conduit. Anyway I am off for a wee cry now

 

[UNG]

Got to agree with the last two posts post #22 is some what over reactive Pyro doesn't become brittle I think you are mistaking this for work hardening. This can be a bit of a problem if the Pyro is sheathed but bare Pyro can be reworked after a bit of heating to anneal the copper, there would be no problem putting a new metalclad CU on those cables for someone with the right experience without resorting to creating a JB of the old CU. IMO any body who claims to have worked with Pyro who couldn't do a straight swop of that CU hasn't done a lot of Pyro and doesn't have a good understanding of it.

Like Oldtimer I used to have made up tools for the medium size stuff for the really big stuff a piece of 25mm tube with a t bar at one end was the best, got volunteered to re term a load of 4H16's, 4H25's and some imperial equivalents one weekend that had to be diverted due to building alterations while another 6 sparks did the rerouting of them still reckon I got the easy job despite what the others said at the time but the tooling helped. Over the years I think I have termed most of the metric Pyro sizes made and a fair few of the imperial ones even though they were before my time and don't see that changing a CU is anything to get stressed about

 

[johnboy6083]

im with UNG and E54. Undo locknuts on the pyro, and unscrew board. Lift board off pyro. Use old board to mark new board up. Drill new holes in new board. Insert pyro tails into new board, and slide down onto the glands. If board is plastic, then use banjos or pyranha nuts to earth the pyro. If a metal board, then scraping the paint away will do the same job. Then install all other cables, and terminate the board. Job done.

PS i havent used pyro on a job since college, and i only made about 10 ends off, but if your careful with it, like anything else, then it will be fine.

 

[supasparxs]

we all seem to be split on the way to do the CU change.

admittedly it would appear that the original spark new what he was doing as he seems to have used bushes and couplers to terminate the gland in the board.
but i still stand by my statement earlier, because we don't know it the cables had been thru a straightener (for those or you who don't know it's a jig with wheels in it that forces the cable straight but it work hardens the cable at the same time)
In addition seals can pop out of pots. as the history of the cable is unknown, I would edge on the side of caution.

 

[panicoll]

To be honest mevans, i can't see too much of a problem replacing this old MEM CU, for a modern equivalent. It'll obviously require a little more care removing the MICC cables from the enclosure, but nothing beyond an experienced electricians capabilities. Due to the MICC cables, it would be better to using a metal CU for your upgrade.

One point i would mention, is that you would do well to try and find an electrician that understands how to handle MICC cables, that i'm afraid would by definition exclude most of the younger electricians.

Oh and also ensure that ALL the other T&E cables entering the enclosure are suitably glanded into the the CU.... Looks like you will need to upgrade the meter tails while your CU is upgraded too. Any existing short cables can be extended within the new CU by means of permanent maintenance free crimped connectors...

EDIT.... Make sure you have the electrician that you employ inspect and test all the circuits before any work begins. I can't see your main earthing arrangement or any bonding conductors for your installation from the photo's you posted. So can't comment on whether or not you need these upgrading too.

Shocking I am only 22 and have worked with more Ex d pyro installs than you old timers!

You Best thing to do is have a PIR done and as a landlord you should only worry about Code 1 or 2's.

oh and Pyro doesn't need to have additional protection(RCD)

 

[oldtimer]

Shocking I am only 22 and have worked with more Ex d pyro installs than you old timers!

You Best thing to do is have a PIR done and as a landlord you should only worry about Code 1 or 2's.

oh and Pyro doesn't need to have additional protection(RCD)

Quite right I was a chargehand electrician with plenty of pyro jobs under my belt the thing is who said you ha to be over 40 to work on pyro ?
I know guys my age (53) who have never worked on conduit ,trunking or a 3 phase system

 

[supasparxs]

Shocking I am only 22 and have worked with more Ex d pyro installs than you old timers!

You Best thing to do is have a PIR done and as a landlord you should only worry about Code 1 or 2's.

oh and Pyro doesn't need to have additional protection(RCD)

never mind your age,
you in Edinburgh which is where the upgrade is.,
If you get the job let us know how it turns out