Almost burned my shop down and didn't even know it

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

GreenTwin

Well-Known Member
HMEM Supporting Member
Joined
Jul 2, 2021
Messages
1,468
Reaction score
686
Location
MidSouth
Quick question chaps

What is Romex wiring it's a term I have not come across in the U.K.. Is it similar to what we call T&E (Twin and Earth) which consists of two Insulated conductors and an uninsulated earth (ECC) conductor in a secondary insulated sheath. it is the standard for domestic fixed wiring here.

Best Regards Mark
Romex is one or more insulated conductors with an overall insulating jacket.
Romex I think is a brand name, but that is what folks call residential wiring these days.

In home use, the wood studs are drilled, and the Romex routed through the studs horizontally, or stapled to the studs vertically.
The smaller gauge Romex such as #12 and #10 is a solid wire, which actually works quite well, but is a bit more cumbersome to terminate in a junction box.
A solid wire makes for a very good screwed connection if you get the screw tight.
Stranded wire has to be carefully terminated so that a single stray strand does not protrude out somehow and conduct too much current, which can melt the single strand.

In industrial/municipal work, solid wire is not allowed, due to vibration and other issues.

Photo attached of typical Romex in the US.
You can get Romex with one or more energized conductors, often called 2-wire, 3-wire, etc.

You have to be careful with Romex when installing the sheet rock on top of the studs that you don't use long screws, and don't drive a screw or nail into the Romex. They do make metal shields that you can place on the studs under the sheetrock to prevent nailing/screwing into Romex circuits, and I have used these devices.

.
Image157.jpg
12-3-NM-B-1-3171940976.jpg
 

ignator

Well-Known Member
Joined
Jan 22, 2012
Messages
222
Reaction score
50
Location
USA, Iowa
A few questions.

Arc faults/flash. If you plug or un- plug anything (like a fan) that is under load, can the arc faults handle that and avoid nuisance tripping?

I like having a gfi recept at the beginning of each electrical run, on every circuit in the house and shop.
Are there any recepts sold in the US that incorporate gfi, afi, and-over current, in the same recpt? Or at least 2 of the 3? Sure seems like it would be handy, but I am waiting for the buzz-kill reply, LOL, as the grandkids call it. ;)

No problem, I can handle it. (Grandpa, you know why you tripped on that board? Cause your shop is a mess! (sigh))
My read on AFCI breakers, early versions had issues with universal motors as brush noise would trip them. They have evolved, I don't know about false trips. I have them in my addition as they were required, and have not had any trips with vacuum cleaners or other motors. My read is they look for high frequency (~100KHz) type signals to detect arcing.
As for sold as a receptacle;
 

GreenTwin

Well-Known Member
HMEM Supporting Member
Joined
Jul 2, 2021
Messages
1,468
Reaction score
686
Location
MidSouth
I did not realize they had combined arc flash protection with ground fault protection in a receptacle.
That is very good to know.

I will have to try one of those.

.

 

ignator

Well-Known Member
Joined
Jan 22, 2012
Messages
222
Reaction score
50
Location
USA, Iowa
And they are 20 amp, too. The start of my shop electrical safety upgrades.
If you have a brand name circuit panel, you can sometimes get used panel based breakers, they look just like the GFCI type, off eBay for less then the typical home store price, or buy in quantity. $45 is what I've see in my local Menards store, but Lowes and Home Depot carry them as well.
I've seen discussions that if they false trip, it's from EMI filter circuits in electronics, which use the earth ground wire to dump noise on to.
I'm seeing discussions for the 2023 NEC requirements that they will be requiring the dual GFCI/AFCI for most locations in the dwelling unit. The upcharge is nominal for these.
 

ajoeiam

Well-Known Member
Joined
Aug 14, 2020
Messages
639
Reaction score
184
Location
blank (like some others I've noticed)
snip

The scariest thing I had happen, and probably the closest I have come to meeting the maker in a spectacular and sudden fashion, is when the pressure regulator on my oxygen tank of my oxy-acetelene cutting rig failed while I was cutting something outside.
I heard a pop sound, and then loud hissing.
I ran into the shop, and turned off both tanks, not knowing which tank it was.
Needless to say, never store your oxygen and acetelene tanks inside a house or shop.

.

With those provisos I would suggest that you never store a car or any other equipment that contains either gasoline or diesel in your shop either.

(have had a tractor fire start - - - didn't burn everything but did make a mess of some wiring - - - you know electrical shorting and diesel isn't a great mix and the gas in a car is plenty to level a much larger building - - - you know - - - it could leak!)

In fact - - - perhaps you shouldn't enter that shop either - - - you know the safety factor after your well enjoyed results from supper (a k a 'natural gas')
could also be dangerous.

Seriously If you shut off your gas cylinders and have them in the upright position - - - - there really isn't a good reason to NOT store such in your shop.

Now if you have a hard time remembering to shut off your torch never mind your cylinders then maybe you shouldn't be using such equipment.

There's working safely and then there's paranoia.

As an example - - - The Empire State building - - - - today the estimate would be for approximately a minimum of 42 months construction time - - - and that would be using fast track engineering design and construction with a likely actual construction time of between 48 to 54 months - - - - the original was built in about 9 months. We have gotten so hyper paranoid about safety that we've forgotten that work also needs to get done.
The last large industrial project I worked on the company vp that did our indoc informed us that this was going to be a 'zero' incident site (a somewhat north of a billion $ project) - - - the 'safety officers' were mostly 9 month course grads who didn't know their butts from a hole in the ground and they were proscribing how we were supposed to be using our equipment. But of course they knew everything about everything. (It was funny in that some time after I was on that site I calculated that for every guy on the tools there were likely some between 6 or 7 others that were employed between the safety officer for every 2 guys, foreman for every 6, then clerical staff, engineering and our pay deposits were still often late - - - ain't it wonderful to be so 'needed'!)

Herewith ends this rant(!!!)
 

JLaning427

Active Member
Joined
Jan 28, 2021
Messages
32
Reaction score
15
Location
Severna Park, MD
My read on AFCI breakers, early versions had issues with universal motors as brush noise would trip them. They have evolved, I don't know about false trips. I have them in my addition as they were required, and have not had any trips with vacuum cleaners or other motors. My read is they look for high frequency (~100KHz) type signals to detect arcing.
I've got some of the earlier arc fault breakers in my addition, as they were required. Went to put in all the trim (baseboard, window casings, etc) and found the my miter saw (with soft start) won't work on those CB's. Trips them nearly instantly. Ended up having to run an extension cord from the older portion of the house to make it work. Other than that issue, AFCB's have been unnoticeable in my application.

James
 

Lloyd-ss

Well-Known Member
HMEM Supporting Member
Joined
Mar 8, 2019
Messages
284
Reaction score
159
Location
Charlottesville, VA
......................................................

Herewith ends this rant(!!!)

Joe, I hear you and I definitely understand. Common sense goes out the window sometimes.

But you know what? Its Sunday morning, get another cup of coffee, maybe a donut, and go to that happy place in your head.
Here is my time travel 35 years into the past.
MossySpringRainbow1.jpg
 
Joined
Jun 26, 2022
Messages
101
Reaction score
27
Location
united states
using romex is much much better than using zip cord (the cause of my friend's fire, pictured upthread, was assessed by the fire department to be electrical, he had a substantial amount of zip cord outside and over a few decades the insulation cracked and probably a rat had something to do with the ultimate fire - never use zip cord for primary (permanent) wiring). If you use a metallic surround (EMT, Rigid, Flex), rats can't get inside and chew on the insulation, and fires are inside a tube with insufficient air to burn, so your breakers have a chance to shut down before you burn up $150K of mostly metal working tools.
 

SmithDoor

Well-Known Member
Staff member
Global Moderator
Joined
Feb 12, 2009
Messages
1,461
Reaction score
232
Location
Clovis Ca
USA electrical code allows multiple 15A outlets (one duplex outlet is a multiple outlet) on a 20A circuit. One simplex 15A outlet must go on a 15A circuit.
I would not do that .
I always put 20amp outlet on a 20amp breaker.
I never put a 15 amp outlet on 20amp breaker.

Today I see a lot tools from China today saying use a 20 amp breaker with 15 amp plug.

Dave
 

WisJim

Active Member
Joined
Dec 8, 2020
Messages
34
Reaction score
16
Location
Menomonie, Wisconsin
Mice can be a real problem. Our old landline telephone wire was chewed through by mice in a box behind a wall mounted phone, and they chewed and shorted out wires to a bathroom exhaust fan, and also repeatedly chewed the wires on a wall light switch. I think that we took at least 5 dead electrocuted mice out of that particular switch box over the years. People sometimes blame the possibility of soy based plastic insulation appealing to mice as a cause of them chewing wires so much. We've also had a number of occasions where mice have chewed up wires and hoses on cars.
Luckily, the worst that happened with the mice and house wiring was tripping a circuit breaker.
 
Joined
Jun 26, 2022
Messages
101
Reaction score
27
Location
united states
1663894124544.png

I was explaining why I am emotionally allergic to Romex, and then, quite fortuitously, on another machinery related forum, this appears - the damage is from squirrels that found the wire to be quite tasty apparently. Consider this a warning provided by hyperspace rodents if you like, eschew Romex.
 

GreenTwin

Well-Known Member
HMEM Supporting Member
Joined
Jul 2, 2021
Messages
1,468
Reaction score
686
Location
MidSouth
Squirrels are the most destructive animals I have ever seen, and they not only chew up electrical wiring, but plumbing, hvac pipes, insulation, soft ductwork, wood, and about anything else.
Having squirrels in your house is the same as having beavers; they are basically mobile chainsaws.

It really pays to keep the house closed up tight, and avoid squirrel infestation at all times.

Rats are not as bad about chewing up wiring, but they do make a mess of things, and they tunnel through any soft ductwork, and will chew up all plastic water piping. I was going to purchase one house, and it had become rat infested below, and when the water turned on, there were perhaps 30 holes or more in the plastic hot and cold water lines. The soft ductwork was their superhighway through the house.
I told the home owner "I don't want the house, and you have a very big infestation and biohazard problem".

But basically all houses in the US in the last 60 years has Romex-style wiring.
For exposed wiring in a shop, EMT or flexible metal conduit would be somewhat rodent-proof, if you used metal boxes.
I hang my rubber cords and occasionally temporary romex from hooks on the ceiling, with drops to the equipment, since I may move my shop one day, and this keeps the rodents off the wire.

If you see any signs of squirrels in the house or shop, you better get a trap or call an exterminator immediately.

One squirrel chewed through the medium voltage copper conductor that was between the medium voltage overhead utility line and the pole-mounted transformer, behind my house, taking down the power to my and several other houses.
Copper is just a snack for a squirrel, and it is no problem for them to chew through it.

.
 

metalmangler

Active Member
Joined
Dec 6, 2021
Messages
32
Reaction score
22
Location
West Wales
I was explaining why I am emotionally allergic to Romex, and then, quite fortuitously, on another machinery related forum, this appears - the damage is from squirrels that found the wire to be quite tasty apparently. Consider this a warning provided by hyperspace rodents if you like, eschew Romex.
When I was first married (50 years ago) My wife and I kept pet guinea-pigs running loose in the kitchen. All was well until the refrigerator failed. On investigating it, I found that all the wiring underneath had lost its insulation, eaten by the guinea-pigs. It turns out that guinea-pigs, like squirrels, have feet that are very good insulators, so they didn't get electrocuted whilst snacking on live wires.
 

WisJim

Active Member
Joined
Dec 8, 2020
Messages
34
Reaction score
16
Location
Menomonie, Wisconsin
Squirrels! One of my sons had squirrels chew through the fascia trim and siding into his attic. We typically had a squirrel electrocute itself on the transformer at our former home. They would clime the pole and short across the top terminals, causing a loud bang and flash and blowing out a fuse down the street. This happened over 20 times over the last 33 years. We would then find a charred squirrel carcase on the lawn under the pole.
 

Richard Hed

Well-Known Member
Joined
Nov 23, 2018
Messages
1,858
Reaction score
450
Location
Moses Lake in the Great Soviet of Washington
Squirrels are the most destructive animals I have ever seen, and they not only chew up electrical wiring, but plumbing, hvac pipes, insulation, soft ductwork, wood, and about anything else.
Having squirrels in your house is the same as having beavers; they are basically mobile chainsaws.

It really pays to keep the house closed up tight, and avoid squirrel infestation at all times.

Rats are not as bad about chewing up wiring, but they do make a mess of things, and they tunnel through any soft ductwork, and will chew up all plastic water piping. I was going to purchase one house, and it had become rat infested below, and when the water turned on, there were perhaps 30 holes or more in the plastic hot and cold water lines. The soft ductwork was their superhighway through the house.
I told the home owner "I don't want the house, and you have a very big infestation and biohazard problem".

But basically all houses in the US in the last 60 years has Romex-style wiring.
For exposed wiring in a shop, EMT or flexible metal conduit would be somewhat rodent-proof, if you used metal boxes.
I hang my rubber cords and occasionally temporary romex from hooks on the ceiling, with drops to the equipment, since I may move my shop one day, and this keeps the rodents off the wire.

If you see any signs of squirrels in the house or shop, you better get a trap or call an exterminator immediately.

One squirrel chewed through the medium voltage copper conductor that was between the medium voltage overhead utility line and the pole-mounted transformer, behind my house, taking down the power to my and several other houses.
Copper is just a snack for a squirrel, and it is no problem for them to chew through it.

.
Squirrels are tasty and if you get enough of them, yuou can make nice gloves
 
  • Haha
Reactions: Zeb

Richard Hed

Well-Known Member
Joined
Nov 23, 2018
Messages
1,858
Reaction score
450
Location
Moses Lake in the Great Soviet of Washington
Squirrels! One of my sons had squirrels chew through the fascia trim and siding into his attic. We typically had a squirrel electrocute itself on the transformer at our former home. They would clime the pole and short across the top terminals, causing a loud bang and flash and blowing out a fuse down the street. This happened over 20 times over the last 33 years. We would then find a charred squirrel carcase on the lawn under the pole.
Already cooked? Add a bit o salt and maybe acouple herbs.
 
  • Like
Reactions: Zeb
Top