Consumer unit change - How do you do it?

[catdog1121]

Dont change many consumer units, usually go ok but had one today that I did cheap for next door neighbour (Why is it always the ones you do cheap for friends and family that bite you). Anyway changed the board etc, all ok. Then came testing and obviously have various alterations in the last 40yrs, still had original wylex rewireable fuses.

I found Neutral ring missing - A socket had a neutral out.
Conservatory had two sockets, a light and an automatic window opener all spured off a spur in the kitchen with no grommets in the back box (Apparently done by an electrician)
One socket of two gang no neutral - just change face plate
One socket no neutral (Spur) - Just had to wago and put blank plate as obviously a junction box under the floor
There was some others as well.

Anyway in my haste to speed up testing I did insulation resistance with a couple of sockets off (I know stupid), when powered on RCD kept tripping if I removed socket neutrals it was fine. Finally tracked it down to a really tight socket in the kitchen that had a damaged neutral cable, managed to sort everything.

Started at 9.30, was running around in the dark finished about 8pm with everything ok, im totally shattered.

I am thinking of insisting on a full EICR before I do a consumer unit change again, at least you know what you are getting into mostly and you dont spend an entire evening trying to chase down issues as once you have changed the board and especially adding RCD's your kinda committed.

Just wondering do others do EICR beforehand or just wing it?

If you just wing it how often do you have issues?

 

[Tiger Feet]

Or sign of a proper torque controlled driver!

Agree
People who do mains changes with impact drivers need there hands chopping off

done lot of work on social housing and number of times I go in and try to torque tighten all existing terminals but only to find been install by some tool with a impact and all screws rounded off
My number 1 thing that grinds my gears!

 

[Grant1987]

I cost in a morning or afternoon, a week or so before the board change, to do pre-board change inspection and test: earthing, bonding, IR, ring continuity, check for borrowed neutrals, and either R1+R2 or Zs on every circuit. When I give my quote, I explain (in writing) that the quote is subject to the existing circuits meeting the minimum requirements of the Regs; if it's something I can quickly and easily fix during the pre-change checks I'm happy to do so. If there is plenty wrong, then I reschedule the board change for further into the future, and spend the day I booked for the board change doing fault-finding and rectification (either as a quote, but usually on an hourly rate). This has happened about 2 or 3 times, out of about 30 board changes, and the client has always been grateful for sorting things out and doing stuff properly.

In theory, if I do the checks and there's a lot to sort out which the client doesn't want to pay for, the client can cancel the board change and doesn't owe me anything. This has never happened though.

I don't like surprises. When I strip out an old board, I want to make sure, as best I can, that the day will go smoothly.

Spot on in my opinion that’s what I do. I don’t charge full whack to do an EICR and then say you need your consumer unit changed and then charge for that. In some cases you already know after visually inspecting property and board cover off that it needs upgrading. So I would do a small fee for pre inspection of property and then set an amount of £350 approximate based on standard property with 6/7 circuits for board change. I will inform customer that should I find any faults after board change I will charge per hour for fault finding. I don’t like the fact that ppl charge £150/£300 for EICR then charge another £350 for board change when you already know that the property needs upgrading prior to EICR

 

[HappyHippyDad]

You do IR tests with all the cpcs isolated from each other and the earthing conductor? I test as I am connecting them.

Yes, you're right Westward, I had to think for a moment. The back of the new board would be up, with all the cables coming into the new unit. Then, I would do individual IR tests just before I connect up the earths to the earth bar.

 

[Grant1987]

Agree
People who do mains changes with impact drivers need there hands chopping off

done lot of work on social housing and number of times I go in and try to torque tighten all existing terminals but only to find been install by some tool with a impact and all screws rounded off
My number 1 thing that grinds my gears!

Yesssss!!! Same here I’m testing a lot and the amount of terminals which are rounded, tightened by Arnold Schwarzenegger is unbelievable even the fuse board covers grips my ---- use your hand tools so you can feel the tension simple
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Yesssss!!! Same here I’m testing a lot and the amount of terminals which are rounded, tightened by Arnold Schwarzenegger is unbelievable even the fuse board covers grips my ---- use your hand tools so you can feel the tension simple

Another pet hate is the earths twisted together in single sleeving why like? Sleeve them individually easy solution is to do end to end at socket but I like the fuse board lol

 

[westward10]

Yes, you're right Westward, I had to think for a moment. The back of the new board would be up, with all the cables coming into the new unit. Then, I would do individual IR tests just before I connect up the earths to the earth bar.

You should connect the cpcs first.

 

[Dustydazzler]

If people are using 18v impact drivers to tighten down terminal screws something went wrong with the trade...

 

[Grant1987]

If people are using 18v impact drivers to tighten down terminal screws something went wrong with the trade...

Exactly I’m normally a calm guy but some of the boards I’ve had to test recently really wind me up. And I never had a problem 7 years ago it’s only the recently installed boards which seem to be glued shut

 

[westward10]

I don't approve of his method but to be fair he seemed well in control of the driver and didn't seem to over do the terminals.

 

[Grant1987]

I don't approve of his method but to be fair he seemed well in control of the driver and didn't seem to over do the terminals.

I suppose if you have an understanding of power tools then it’s fine one of my best mates does it with impact and I cringe every time I see/hear him at the consumer but to be fair he understands the torque it’s the ones who don’t have knowledge/experience that cause the problems anyhow I don’t like power tools at consumer

 

[telectrix]

i run them down with a cheap 4V battery driver with torque settings, then hand tighten to correct tightness.

 

[Grant1987]

i run them down with a cheap 4V battery driver with torque settings, then hand tighten to correct tightness.

Nothing wrong with that. Thats experience and knowledge

 

[nicebutdim]

I suppose if you have an understanding of power tools then it’s fine one of my best mates does it with impact and I cringe every time I see/hear him at the consumer but to be fair he understands the torque it’s the ones who don’t have knowledge/experience that cause the problems anyhow I don’t like power tools at consumer

The drill/driver is used in that video is not an impact driver and can be set to exceptionally low torques. I've no idea what it was set at and whether or not those terminals were over/under tightened, but it's worth noting that they are very different tools.

 

[Grant1987]

The drill/driver is used in that video is not an impact driver and can be set to exceptionally low torques. I've no idea what it was set at and whether or not those terminals were over/under tightened, but it's worth noting that they are very different tools.

Doesn’t matter shudn be using them unless like @telectrix just posted then that’s the exception “HAND TOOLS ONLY”

 

[nicebutdim]

Doesn’t matter shudn be using them unless like @telectrix just posted then that’s the exception “HAND TOOLS ONLY”

Drill drivers can be set to exceptionally low torques - often so low that it wouldn't be considered much more than hand tight.

Having said that, I just looked at the video again and note that it is indeed an impact driver

 

[Grant1987]

The drill/driver is used in that video is not an impact driver and can be set to exceptionally low torques. I've no idea what it was set at and whether or not those terminals were over/under tightened, but it's worth noting that they are very different tools.

What

The drill/driver is used in that video is not an impact driver and can be set to exceptionally low torques. I've no idea what it was set at and whether or not those terminals were over/under tightened, but it's worth noting that they are very different tools.

what do you use mate? Drill/driver is it?
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Drill drivers can be set to exceptionally low torques - often so low that it wouldn't be considered much more than hand tight.

Having said that, I just looked at the video again and note that it is indeed an impact driver

??

 

[nicebutdim]

I don't regularly fit consumer units - in fact I've fitted a grand total of one and the use of power tools was limited to mounting it.

 

[GBDamo]

If people are using 18v impact drivers to tighten down terminal screws something went wrong with the trade...

I'll be honest if I've got a board full I'll wizz all the terminals fully open with the driver and tighten them back up just tight enough to hold then run down the lot with the torque driver.

If you use an impact enough then you can be quite gentle with it.

Never rounded a screw yet

 

[Grant1987]

I'll be honest if I've got a board full I'll wizz all the terminals fully open with the driver and tighten them back up just tight enough to hold then run down the lot with the torque driver.

If you use an impact enough then you can be quite gentle with it.

Never rounded a screw yet

Ok so you’re under the category of experienced but I’m sure you agree with the fact that it’s more sensible to hand tighten terminations so you can feel the tension
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I don't regularly fit consumer units - in fact I've fitted a grand total of one and the use of power tools was limited to mounting it.

Good man stick to the hand tools once mounted ?

 

[GBDamo]

Ok so you’re under the category of experienced but I’m sure you agree with the fact that it’s more sensible to hand tighten terminations so you can feel the tension

There's a time and a place, if its an obsolete MCCB it'll be hand tools only, if its a board change and mistakes can rectified the returns outweigh the risk.

What does grind my gears is certain manufacturers applying thread lock to terminal screws, not sure how that helps come EICR time.

 

[Mike Johnson]

I don't know how these manufacturers calibrate their torque screwdrivers, but mine was so far out it could not be tightened to 2.1N required by Hager without bending the Din rail the RCBO was fixed too, anyone want to buy a full set of Armeg drivers?

 

[Grant1987]

I don't know how these manufacturers calibrate their torque screwdrivers, but mine was so far out it could not be tightened to 2.1N required by Hager without bending the Din rail the RCBO was fixed too, anyone want to buy a full set of Armeg drivers?

Normally it’s 1.7N isn’t it? Only 2.1 or higher for main switch you don’t need torque settings to know the correct torque I don’t think aslong as you understand the recommendations
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Normally it’s 1.7N isn’t it? Only 2.1 or higher for main switch you don’t need torque settings to know the correct torque I don’t think aslong as you understand the recommendations

Difficult area but again like I said it all boils down to experience and knowledge

 

[Mike Johnson]

None of Hagar's equipment is recommended to be torqued to as low as 1.7N, in fact it can be as high as 3.6N.

 

[pc1966]

What does grind my gears is certain manufacturers applying thread lock to terminal screws, not sure how that helps come EICR time.

It would depend on the type of threadlock.

Some is soft and easy to undo, only to stop gross loosening from vibration, etc. But some (e.g. "studlock") is like superglue and never expected to be undone without serious force!

If you do need to stop an adjuster from moving unintentionally and don't have anything special to hand you can use a dab of nail varnish, which you can get pretty much in any local chemist or supermarket.

 

[telectrix]

i have a small bottle of Loktite on the van. still half full after 20 years of occasiona luse.

 

[DPG]

It would depend on the type of threadlock.

Some is soft and easy to undo, only to stop gross loosening from vibration, etc. But some (e.g. "studlock") is like superglue and never expected to be undone without serious force!

If you do need to stop an adjuster from moving unintentionally and don't have anything special to hand you can use a dab of nail varnish, which you can get pretty much in any local chemist or supermarket.

It's a good excuse for why you're carrying nail varnish as well. I always carry women's tights as well in case my fan belt breaks.

 

[Zerax]

It's a good excuse for why you're carrying nail varnish as well. I always carry women's tights as well in case my fan belt breaks.

In case there are any woke snowflakes reading this... I should add that mens tights would work just as well.

 

[HappyHippyDad]

You should connect the cpcs first.

So when you test N-E for a particular circuit you will have all the CPC's connected in the earth bar? What would be wrong with doing the IR testing of N-E without having the CPC's in the earth bar? Are you saying parallel paths could cause different results? Are we not testing that particular circuit, i.e that particular cable, which is why we put the test result in the little box related to that one circuit?
A lot of questions there!

 

[ChrisElectrical88]

So when you test N-E for a particular circuit you will have all the CPC's connected in the earth bar? What would be wrong with doing the IR testing of N-E without having the CPC's in the earth bar? Are you saying parallel paths could cause different results? Are we not testing that particular circuit, i.e that particular cable, which is why we put the test result in the little box related to that one circuit?
A lot of questions there!

There could be Parallel paths to earth. I’ve never know anyone to not IR test with everything connected to the MET

 

[westward10]

See Regulation 643.3.1

 

[pc1966]

What would be wrong with doing the IR testing of N-E without having the CPC's in the earth bar?

The CPC of the circuit being tested is probably isolated from all the others CPCs and the Earth, so you would not see a leak from N to true Earth (e.g. a screw, etc, that is touching the N copper and in to plasterboard, etc) as it would not be guaranteed to complete the circuit from true Earth to CPC and back to your IR tester.
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Basic idea is this (sorry for poor diagram):

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So IR testing with the CPC isolated will pick up on an internal cable fault (say N to E), but not for external faults (N to some other CPC or true Earth).