More wiring crimes

A meeting place for regulars to discuss the lighter side of old-houses.

Moderators: oldhouse, TinaB, Don M, Schag

Re: More wiring crimes

Postby Texas_Ranger on Thu Nov 03, 2011 6:39 am

One big difference is that our panels are all field-built - you buy a generic box the size you want (common sizes are 12, 24, 36 and 48 breaker spaces but much larger ones are easily obtainable, I think up to ten times that size for commercial work, and combined meter cabinets/panels for single family homes often have 108 spaces) with standardised mounting rails (used everywhere in Europe as well as Australia, New Zealand and lord knows where else) and snap in your breakers. There are plenty of other rail-mount components too, such as doorbell transformers, outlets, timers, relays,...
The load side of the breakers is either connected using jumper wires or bus bars from the breaker manufacturer.

The neutral is commonly switched to make tracing neutral-to-ground faults easier. To find the affected circuit, the circuits need to be fully isolated one by one and just flipping the breaker is much easier than ripping the neutral bus apart. That's another regional difference - the Germans always use single pole breakers and a plain neutral bus. In Austria it's recommended to switch the neutral, in France, Belgium and Italy it's a code requirement.

What I like best about 3-phase is how easy it is to wire a range - just imagine running a 14-4 cable to a range! It doesn't need more than 16A per phase if the load is split up. A really large one might go up to 20.
The bad thing with electricity : it almost always works.

http://whatapigsty.blogspot.com
Texas_Ranger
 
Posts: 2355
Joined: Mon Feb 09, 2004 6:42 am
Location: Vienna, Austria, Europe

Re: More wiring crimes

Postby jharkin on Thu Nov 03, 2011 8:57 am

I think you would say our panels are somewhat field built as well. You get a panel box, that typically come in 20,30 or 40 breaker sizes (20 and 30 for a code minimum 100amp service, 40 for 200, all-electric households and huge mansions that use 300 or 400 amp service would usually have 2 panels). Inside the panel box the 2 hot legs connect to a pair of vertical bus bars that look like the interconnecting teeth of a zipper - alternating the hot legs by row to facilitate double pole breakers and balance the load. There is a netral bus bar on on one side of the box and a ground bus on the other - ifs its the main service entrance they are bonded together at that point - any downstream subpanel has to have the neutral bar isolated.

That switched neutral is an interesting idea... would sure make finding bootleg grounds easy.

I like that 3 phase range hookup ( I assume its 3 hots and a ground, so its all line to line loads?). Our ranges use both 120 and 240 so modern code requires a 4 wire connection. In the old days they allowed a 3 wire connection sharing the neutral and ground, which is grandfathered in unless you need to relocate or repair it then it has to be upgraded. My range was acting funny and I found that someone had relocated it twice, splicing in more ungrounded wire badly with the metal junction box serving as the neutral conduction path (lovely) so I ripped it out and rewired it. Ranges usually need 40 or 50 amps (mine is 40), but the cords and outlets only come in 50 amp size I sized everything for 50 but kept it on a 40 breaker. Guess what - that meant I had to pull 6/3 w/ground!!!! (3 #6 stranded and 1 #10 solid ground). Holy (^%*#@ that was a pain.
jharkin
 
Posts: 605
Joined: Thu Mar 26, 2009 3:37 pm
Location: Holliston, MA

Re: More wiring crimes

Postby triguy128 on Thu Nov 03, 2011 10:08 am

One thing about electrical... if I custom built a home today, I'd spend the extra cash and wire use coundit and stranded wire. Imagine how easy any of our olds homes woudl be to rewire if it was all in conduit. A nice insurance break might even make it relatively cost effective. The only thing to be careful of, would be possibly using a different color or a stripe for 220 vs. 110 circuits and making sure all wires get label at the junction boxes, then label the outside of the j-boxes too.

Really, wire, circuit and j-box labeling should be required by code IMO.

Speaking of safety, also required should be permenant tie-off anchors on all roofs. I'm adding 2 anchors to my roof this weekend. Now when I'm working more than about 6' high off a ladder I can have a harness and a vertical lifeline. That does mean I have to take the extra step of going up on the roof and connecting the line.

I also use safety glasses and ear plugs when I do yardwork with powered equipment.
1925 Neo-Classical

Previous home - 1968 single story Ranch/Colonial, 1200sqft - 11 windows
Current home - 1925 2 story Beaux Arts Neo-classical overlooking the Mississippi River, 3200sqft - 48 Windows
triguy128
 
Posts: 708
Joined: Mon Sep 12, 2011 9:41 pm
Location: Keokuk, Iowa

Re: More wiring crimes

Postby Texas_Ranger on Thu Nov 03, 2011 7:27 pm

I think you would say our panels are somewhat field built as well. You get a panel box, that typically come in 20,30 or 40 breaker sizes (20 and 30 for a code minimum 100amp service, 40 for 200, all-electric households and huge mansions that use 300 or 400 amp service would usually have 2 panels). Inside the panel box the 2 hot legs connect to a pair of vertical bus bars that look like the interconnecting teeth of a zipper - alternating the hot legs by row to facilitate double pole breakers and balance the load. There is a netral bus bar on on one side of the box and a ground bus on the other - ifs its the main service entrance they are bonded together at that point - any downstream subpanel has to have the neutral bar isolated.

Yes, of course... the difference I wanted to stress was that the bus bar assembly (hots and (where switched neutral breakers are used) neutral) are not part of the panel assembly but bought separately. If you buy a Square D panel in the US, you're stuck with using Square D breakers forever. If you have a DIN rail panel, you can use any breaker you like, though you might have to use jumper wires rather than bus bars if you mismatch.

Neutral bonding location depends on the power company here. It can either be done outside, ahead of the meter or in the main panel as in the US. Prior to 1978 it was even legal to use the neutral as a ground throughout the home wiring and not have a ground rod at all - just two wires at every outlet and a short jumper to the ground terminal. Pretty scary, especially if the neutral breaks.
Then there's the so-called TT system (French acronym) where the neutral isn't earthed locally at all and the house ground wires are only connected to a ground rod.

BTW, I recently went to some kind of scrap dealer who had acquired lots of new-in-the-box electrical stuff from a defunct company and guess what I found... a brand new unused GE 6-space breaker panel! I don't have the slightest idea how it made its way to Austria...

I like that 3 phase range hookup ( I assume its 3 hots and a ground, so its all line to line loads?).

No, it's 3 phases, neutral and ground, and the elements are line-neutral loads. The typical range has 4 elements and a single oven, 2 elements sharing one phase each and the oven on the third. In theory that's 11kW, but few ranges (except for those in the upper 4-digit price range) exceed 8kW. As they're line-neutral loads they can of course be connected to a single phase supply, but that's a lot of trouble, since it's usually only required in places with very old wiring which usually won't support large single phase loads either.

I think the Swiss have ranges with line-line elements, often fed with only 3 wires plus ground.
The bad thing with electricity : it almost always works.

http://whatapigsty.blogspot.com
Texas_Ranger
 
Posts: 2355
Joined: Mon Feb 09, 2004 6:42 am
Location: Vienna, Austria, Europe

Re: More wiring crimes

Postby jharkin on Thu Nov 03, 2011 10:01 pm

Texas... ahh got it now. Yes that makes sense. So when you said 14-4 you were referring to a cable with 5 wires the way my 6-3 has 4 wires. Still sounds a lot easier.

triguy. Your labeling idea is interesting. I actually started doing that myself as I go around working on things so I remember later. But im an anal (*&*(^ engineer. I doubt they would ever make it code though, I cant see a professional electrician doing a job like a main panel upgrade and then going around and relabeling every box in the house.


We are making OHW start to sound like electricaintalk.com (its a real site BTW) ha!
jharkin
 
Posts: 605
Joined: Thu Mar 26, 2009 3:37 pm
Location: Holliston, MA

Re: More wiring crimes

Postby Texas_Ranger on Fri Nov 04, 2011 4:23 pm

In commercial construction it is pretty common to label everything here, but not in homes. Here you're lucky if they didn't "forget" the circuit directory in the panel... but even if there is one, it might have helpful things as "Lights 1" or "Room 1+2" and it's your guess what that might mean...

At our own place they labeled the breakers with a DYMO back in the 70s but the strips just fell off... then they used a sharpie, made a bunch of changes, covered the sharpie writing with brown packing tape, labeled anew,... I temporarily labeled everything with a pencil but I have to devise something more permanent.
The bad thing with electricity : it almost always works.

http://whatapigsty.blogspot.com
Texas_Ranger
 
Posts: 2355
Joined: Mon Feb 09, 2004 6:42 am
Location: Vienna, Austria, Europe

Previous

Return to The Hangout Forum

Who is online

Users browsing this forum: No registered users and 1 guest