The wiring in this commercial establishment is such a mess it's hard to know where to start, so it may as well be with the service entrance.

These always tend to be messy here, but note the cables to the heating contactor (black box, lower left) just draped along the floor:



Here's the view slightly to the right:



The MEM 3-phase switch-fuse is no longer in use (everything is running on one phase), but still has power applied. Note the "deliberate mistakes" in the way it was installed:



Here's what's left of a light fitting, now suspended solely by the wiring. Note also the method of junction box wiring, which is repeated throughout much of the store:



The light and exhaust fan wiring in the W.C. area:

Here we have a mixture of power, telephone, and alarm wiring installed by the "minimal fixings" method:



This is the other side of the partition. The wire draped across from the fan actually goes to a PIR sensor for the alarm, which is just hanging on the far side of the fan. More loose cables to switches and the fluoro light can be seen in the background:



And this is the power source and controller for the fan in the last picture. Yes, that's "T&E" (Romex-like) from the plug to the switch:



More hanging cables, this time running into a small area at the rear of the store which has been partitioned off to form an office. Just about visible are more loose cables dropping down to the right of the black ring binders which go to a receptacle behind the cash register:



Here's where one of the above cables goes within the office, to feed the only functioning receptacle within the area. I think the saw is a nice touch! Oh, and notice the ingenious lighting arrangement too!



At this point I should explain that this was originally three separate units, so there are three electrical services, one of which is pictured above. The second is completely disconnected, with meters removed and just the service head remaining (now boxed in and inaccessible).

The third is at the rear of the store in the office area, and at first glance it appears that the 1.0mm cable draped into the office is taking power from this service out to some other part of the store:



However, this rear service is not being used, and apparently an "electrician" ran this cable through when the units were knocked into one to bring power to the rear area from the service at the front. So the cable you see here tapped into the load side of left-hand fuseway is actually now the supply for the rear lights:





[This message has been edited by pauluk (edited 11-05-2006).]

In the first post, pic 5, the W.C. area, look at the junction on the left. Looks like some fire has already happened there.

What a mess!! And since this appears to be an automotive parts store, pity the fire brigade that has to respond when this wiring lights the place up for real.

I feel sorry for the guy in the WC when that wire touches off!

(That is, if I understand "WC" correctly.)

Ian A.

What a mess pauluk.

There is a fire waiting to happen here if not already.

That shop should be closed for a rewire by the labour department, certainly when the public has acces to that place.

That fluor. lamp trick is familiar. Our church added cabinets in the basement, but simply cut the wallboard around the wrap for the fixture (they even matched the radius of the plastic!). Now we have 4 dead lamps and no way to change them short of demolition... Good luck if you plan to re-wire.

Paul, please excuse this Yank's ignorance. Which box does what?

In the first picture, is the large grey box in the lower right the service entrance?

What are the 3 smaller boxes on top and why does one have three grey cables coming out of it?

I assume the top silver box with the 123 stickers is the cash register, but then what is black box with the display?

The second picture with the unused 3 phase disconnect and the two distribution panels, what are the black things?

Are there two cables cut off just below the storage heaters distribution panel? Are they live?

Thanks for all of the answers.

Larry C

West channel? Wayside chapel? there are so many jokes about that. Speaking of joke, that wiring is awful. A real mess. Tear it all out and start over, which someone may have a chance to do if it goes up in flames.

I'm not sure if that dark patch is overheating or just shadows when I took the picture or an unpainted part. I'll check when I get the chance.

Well, the good news is that the local fire station is only about 200 yards away!

I think you do!

Yep, the tenant asked me about "doing something" with the wiring after his insurance agent became rather unhappy. Of course, given the present state of the wiring the only sensible option is to rip it all out and start over.

It must be a little confusing when you're not used to seeing this stuff, so let's see if I can explain it all!

Yes, the large black cable entering that service head from the right is the underground supply from the street. This is our standard 4-wire 415Y/240V system.

These are part of the service head and are pull-outs which contain cartridge fuses (60A each phase in this case). There are always PoCo-owned (and sealed) fuses between the supply and the meter here, whether a 3-phase commercial service like this one or a 1-phase residential.

The connections to the right of the fuses, still part of the service head, are to the neutral.

There are actually only two cables going to the right-hand fuse:

Click for closer view

One of these loops down to the small black fuse holder on the right, and from there a smaller cable (along with a similar-size cable from the neutral) runs to the black box to the left of the meter, which is a timeclock. This is used to turn on the power to the storage heaters at night via the contactor which is the other black box at the bottom.

The cables bringing power out from the meter (you can see the three phases taped red, yellow, and blue) are looped behind the board and are the four gray cables you can see emerging in a bunch on the right, along with the two earth conductors which are connected to the neutral.

On the latter point, this is a PME or TN-C-S system, which is similar to the usual American grounding system except that this is the only point at which the the bond is made. Neutral and ground are kept strictly separate from this point onward, even in the main distribution panel.

They are just heavy-duty junctions, commonly called "Henley blocks" for the name of a common make. There are two separate block in each unit, so the one on the left is being used to join one phase plus neutral (the one on the right is unused).

So, two of the phases coming from the meter run directly to the now-unused 3-ph disco. The third phase and the neutral are then tapped at the Henley block to go to both the 3-ph unit and the 1-ph main panel on the right.

No; it's not too clear from the photo but they actually turn and go into the heating panel.

One runs directly to the Henley block to pick up the neutral. The other (just about visible in the dirt at the bottom of the wall) runs back to the contactor, and of course the other cable from the contactor is the remaining cable you can see here which is tapped onto the phase.

Unfortunately, this sort of messy service equipment is all too common.

It does look a little strange to us Yankees (and Mets too) that individual wires there are not in some form of raceway. Like conduit, or such.

Thanks.

Larry C

Judging by the state of the wiring you can see here, I guess it won't come as too much of a surprise that I received a call yesterday to say that two of the fluoro lights at the end of the central aisle had stopped working.

By the time I investigated this afternoon, they were back on, although I was informed that they had done a lot of flickering on and off while "making noises" before coming back on fully.

Turns out that the neutrals in the terminal block of the upstream fitting were loose (as were the screws holding it to the ceiling).

I also found that the ground wires on the incoming and outgoing cables had been connected together, but were not linked to the ground terminal on the light.

Who knows what other problems lurk in this lot?

A few more pics as I've started to strip out the old wiring.

A.C. 240V power, LV D.C. & video to the CCTV cameras, plus LV alarm wiring all stuffed into the same trunking:



A closer look at that switch bank:



I've already found several places where the trunking was hiding "choc-blocked" joins, such as these:



And here's the wiring to the xfmr for the spotlight:




Oh yes..... And on at least half of the switches/sockets I've opened up so far one or more wires has just fallen straight out of a terminal as I've pulled the device from the box.


[This message has been edited by pauluk (edited 12-20-2006).]

Wow, we could never get away with wiring like that here, especially the service entrance. To be honest, that equipment looks more like a phone system than an electric service. Bad wiring or not, it's difficult for us on the other side of the pond to understand what a "good" installation should look like in the U.K.

That gray "T&E" cable looks like the cable that we use for wiring low-voltage on boats, trailers or RVs. The differences between U.S. and U.K. wiring standards are pretty amazing. Our standards include heavy restrictions.

Perhaps you could post some pics where it is done the right way so we have some idea? Here in the States, we can't ever have individual phase conductors running open like that. They must be within a cable or in conduit.

[This message has been edited by EV607797 (edited 12-20-2006).]

You mean the cables running from the meter to the panel? That seems to be an absolute UK particularity that only exists there and in UK influenced countries. In most of continental Europe I've never seen anything like this.

Here in Austria all wiring around the meter is supposed to be hidden by the meter base, which can only be removed by breaking the PoCo seal, making the wiring more or less tamper resistant. I think somewhere I still have pictures of a fairly recent Austrian service.

Except for the cables to the contactor dragging along the floor, the wiring you see in photo #1 is fairly typical of indoor service boards here.

The cables between the service fuses & meter, and between the meter and panels are double-insulated; there's another layer of red or black insulation under the gray sheath.

Here's another typical older indoor arrangement, this time a single-phase 2-wire (240V) domestic service:



The underground supply from the street enters at the bottom right to the service block/fuse. The unit to the right of the meter is the Economy-7 timeclock, and the black box below the meter is just a junction box. The distribution panel visible to the left is new here, but the rest of the equipment is "traditional" style.

Here's a more modern residential service with the meter accessible from outside in a plastic cabinet, and no added complications of dual-rate tariffs:





The cables disappearing out the back of box run through trunking to the main panel which is located higher up the wall in the inside of the house.

It's our equivalent of Romex, commonly used for residential and light commercial wiring, except that there's no paper under the outer sheath. A couple of people have likened it to American UF cable. See this thread for visual comparisons:

U.S. Romex vs. U.K. \"Twin & earth\"

I've just scanned through a load of photos and I seem to have plenty showing things done wrong and very few showing correct installations!

Anyway, here's a quick run through some more of the issues shown in the pics above.

Photo #3. The unused but still energized 3-ph disconnect. Metal-clad unit with two phases entering through one knockout and the third phase plus neutral entering through another. There are also no grommets or bushings installed to protect the cables. (Note that you can clearly see the double-insulation on the phase conductors in this picture though.)

Photo #4. Apart from the obvious broken lamp holder just hanging on the wires, that's one of our standard round junction boxes on the wall to the right, similar to these . The problem here is that the earth conductors have been brought outside the box for connection instead of being kept inside. It's a fairly common thing to see when somebody needed "just one more" terminal in the box.

I actually started opening up that particular box yesterday and found (a) that the earth conductors pretty much fell straight out of the terminal when I touched it, and (b) that the threads of the plastic screw-on lid where smashed up and it was only the earth conductors pulled over the top which were keeping the cover (loosely!) in place.

Photo #5. Apart from the obvious messy appearance, there's at least one cable which is clearly not properly clipped to the wall. "T&E" (Twin & Earth) can be surface run, but it should be secured properly. And to answer an earlier query about this picture, the black spot around the left-hand junction box turned out to be just a mixture of shadows and dirt. Note once again the earth wires terminated outside that box.

Photos #6 & 7. Cables not properly secured, and just plain messy.

Photo #8. T&E is for fixed wiring and should not be wired into a 13A plug.

Photo #9. More unsecured cables, and although not really visible in the picture there's another "choc block" join just taped up hanging out of the trunking over the counter area.

Photo #10. Insecure cables again -- Looks as though they were just draped over the partition when it was erected.

Photos #11 & 12. Another fairly typical looking service and panel, except for the cable addition which I described above. This lash-up to keep all the rear lights working when the three units were knocked into one has also left an exceesive load on the remaining lighting circuit.

I didn't even bother to look into the remaining wiring that closely, but just from the couple of items I've come across so far in removing it, I've found spurs from a 30A ring feeding multiple outlets (not just two or three, but a half dozen or more), which is not permitted under our Regs.

In my 12/20/06 post:

Photo #1. LV cables are not supposed to share trunking with 240V power unless the LV cables are insulated to the higher voltage.

Photo #2. The outer sheath of the T&E should extend right into the switch box, not have the internal conductors showing as here. That 4-gang switch was mounted on a very shallow box (the 1/2-inch type), so with the number of cables entering it I doubt that whoever fitted it could get all the cables in there and still be able to fit the front on!

Photo #3. The good old "choc block" strikes again. CLick here to see the connectors in question. These can be used in proper enclosures, but there should not any such joins within the trunking as can be seen here.

Photo #4. Flex (standard "line cord") just connected to the xfmr primary with insulated crimps, no enclosure or anchorage. (I bet those crimps came from the rack of electrical parts at the other end of the store!)

You wouldn't think he'd have a coupla wiper blades for my 71 Spitfire would you?

TW

Paul,
In pic #5(first lot), is that a man-hole cover that that wiring runs over?.

Afraid not; they don't carry specific spares for older vehicles. Wiper blades are just the modern "generic" types.

I think you'd probably need to go to a "Classic Parts" type of place. Try here for Triumph spares:
http://www.jamespaddock.co.uk

On the ceiling?!

It's just a plywood patch over the plasterboard which in turn has had another painted piece of wood fixed over it. My guess is it was done when the fan was installed.

It's a flat roof on the building, and there's plenty of evidence that it has leaked quite extensively in the past. Several areas of the ceiling inside are "mushy," to say the least (when I tried to drill through to the joist in one spot a whole section about 18 inches square just fell out!).

As there was quite a bit of interest in this thread I thought I'd snap a few "after" photos. As you can see, I've rewired throughout in PVC conduit.

Two duplex recepts. ("twin socket outlets" in Brit-speak) are now in the office in place of the previous one-outlet lash-up:



This is the area which formerly had "T&E" (NM-style) cable draped everywhere to feed the office (the pink-painted trunking now contains just the CCTV cables):



A couple of shots of the same areas pictured above, as they are now:





The central aisle, not pictured before but it had a variety of fluoro lights at all different angles and with the same sort of lash-up wiring. Now just four 8-foot 100-watt fixtures in a line:

The former W.C., now turned into a proper kitchen area (remember this place started as three separate units, so there's another W.C. at the back). The old fan is still on the board at the moment to keep the hole covered up. The proprietor is going to "do something" with the ceiling before it's painted. Not my department! That's a 7kW instantaneous water heater over the sink unit now:



The fan and light wiring in the rear W.C. was as bad as that in the one above. Here's what it looks like on the ceiling now. We retained the original exhaust fan:



Now the rear storage area. The blue door used to be the exit into an alleyway at the back of the complex, but this has all been covered in now and shared between the different stores. There's a fire door (crash bar to open) at the opposite end, so this constitutes the second fire exit, hence the emergency light (3-hour, non-maintained):




P.S. In that last pic, my conduit is level, but unfortunately the ceiling and blockwork are not! What can you do?

I have just a few more photos, but it's way past bedtime, so they'll have to wait until tomorrow!


[This message has been edited by pauluk (edited 01-16-2007).]

That's the point where I usually decide to put my stuff parallel with the building instead of level. Just looks better.
For example, almost all of the light switches are slanted here... but no one notices because they are parallel to the door frames. Had I put them in level everything would look crooked.

It's interesting... that kind of conduit clamps and round junction boxes went out of favor here decades ago. The saddle clamps are still sold, but I haven't managed to find such boxes. Only square 10 and 12 cm (and larger of course).

I like the conduit work Paul!.
Man, what a difference white conduit makes, over the grey stuff most commonly used here.
I was using the term "man-hole" in the context as it is used locally, meaning any access way to get go a roof void or under-floor area.
Final question,
Did you use 2+E cables or conduit wires inside the conduit?.

I use that approach sometimes, but in this building there are just places where no matter how it's aligned it's going to look out of whack with something.

That former-W.C./now-kitchen area is a prime example: The ceiling twists and slopes in both planes, the rear wall is neither vertical nor flat, no corners are 90 degrees, and the two side walls aren't anywhere near parallel. The blockwork in that rear store runs straight for a while, then takes a nosedive.

The type of conduit I used is available in black and white.

Conduit singles. Running T&E in conduit isn't a normal installation method here, except for where a short length ofconduit is being used for extra mechanical protection.

To finish off the photos, here are just a few I snapped during installation to help show our methods in answer to the request up the thread.

Here's the main bond to the water service.
This is our standard type of pipe earth clamp, used here with 10 sq. mm. cable (roughly equivalent in size to #7 AWG):



Actually, this is one of two main bonds, since the building still has two water supplies in use from when it was separate units. The bonding cable passes uncut through the clamp on the first service. (And you don't want to know what state the bonding was in before.....)

Here's a double socket outlet, which as you can see happens to be at the end of a run (it's the one in that rear store/exit area). Our Regs. don't actually require a separate connection between the socket and the backbox so long as at least one of the mounting lugs is fixed, but I always like to fit one anyway. New "harmonized" European colors now, of course:



Here's that same outlet fitted, energized, and being loop tested:

And finally, the new distribution panel, partially installed:



All circuits now in place, just waiting for a quick "tidy up" inside (forgot to snap a photo after that, sorry!):



And all finished, other than the inspection labels etc. to go on the outside:



The left-side main and MCB (16 amps) are the off-peak supply for the solitary storage heater.

The other circuits, counting from the right are:

1. 32A Water heater
2. 20A Sockets: front of store & window
3. 20A Sockets: central sales area, kitchen, side storeroom
4. 20A Sockets: counter, rear, office
5. 16A Sockets: tool display & counter
6. 10A Lights: two aisles
7. 10A Lights: third aisle, store, kitchen
8. 10A Lights: behind counter, rear area, office, W.C.

(Sorry, fellow Brits, no ring circuits employed on this job at all! ).

Conductors for the final circuits are 1.5 sq. mm for lights, 2.5 & 4 sq. mm. for sockets (larger size needed in some conduits due to derating for groups), and 4 sq. mm for the water heater.

See here for metric to AWG conversion chart:

Conversion Factors and Tables



[This message has been edited by pauluk (edited 01-18-2007).]

Paul, the distribution board above (pic #2 in the last post) am I correct in saying you would remove the yellow tabs then screw a new breaker on to the exposed connection?
Also why no ring main circuit, I thought that was the norm for UK wiring.

Excellent work, Paul. That's quite a vast improvement!

I've said this before, but I always cringe when I see how cramped your boxes and panelboards are.

And the harmonized colors....yuck! But, I can see that when they are used in a job from scratch with no existing "old system" colors, they are easier to manage. You're pretty much stuck with using them, right? Can you even buy red and black single conductors anymore?

Are those conductors that you pull into the conduit solid or stranded?

Peter

Correct. Over the last few years our panels have acquired all manner of extra insulation so that just about all "hot" parts are still covered up even when the outer cover is removed. If you look in the picture just above that one I hadn't fitted the yellow covers yet, and you can just about see the lugs on the copper busbar behind the wires.

Yes, the ring is pretty much accepted as the norm and you'll find it used in most new installs here (domestic and commercial), but radial circuits are equally acceptable. Our "Regs." have included certain standard radial circuit arrangements for a long time.

Personally, I'm not a fan of the ring circuit and try to avoid it whenever possible. In this particular place -- much longer than it is wide and with the panel at one end -- radials are easier anyway, in my opinion.

It's mostly just whatever stock is left over now, e.g.
http://www.tlc-direct.co.uk/Main_Index/Cable_Index/Clearance_Cable/index.html

Black is still available in singles, because it's now a phase color.

Old system:
Phase A = red
Phase B = yellow
Phase C = blue
Neutral = black

New system:
Phase A = brown
Phase B = black
Phase C = gray
Neutral = blue


The 1.5 and 2.5 sizes are available in both forms. 4 sq. mm and upward is all stranded.