On/Off switches

Model Railroader General Discussion (Model Railroader)
41

Going back to my home inspector training classes, the circuit you have all this stuff plugged into, could/would eventually get overloaded, which heats things up, and trips the breaker, hopefully, if all is working right, and repeated tripping of said breaker causes it to get weak.

Generally, outlets are wired for 15 amps, using 14ga. wire, but you don’t know that unless the main panel is clearly marked, so you can see what size breaker is feeding the circuit your power strips are plugged into.

Office, and generally kitchens, and utility rooms, are wired for 20 amps, using 12 ga wire, and a 20 amp breaker.

Consider the surge protector, plugged into a 15 amp circuit, with a couple of computers, or maybe a printer, etc, plugged into that. Than someone uses a remaing outlet on the surge protector and plugs in a power strip, powering maybe a space heater, microwave, coffee machine, et., etc. Overload. Power strips are usually clearly marked as to there designed amperage.

Maybe that was the fire inspectors issue. Don’t know, no body asked.

I will also add that electricity was not one of my stronger areas. I’m more of a structural guy.

Mike.

42

My guess on the fire marshall and the power strip is that the strips all say ‘for temporary use only’ and shoved under your desk with the dust bunnies surely doesn’t count as temporary use. We all use them permanently, but that’s not what they’re spec’d for.

43

Overmod, I have a degree in civil engineering. I am licensed in two states. I graduated from college and the only courses that kept me from graduating with honors is the physics course in electricity and magnatism, and introduction to electrical engineering for non EE majors. In the later case, I think the professor took pity on me and passed me. Suffice it to say that I did not do well in those two courses.

I do appreciate your rather extensive explanation. However, ultimately all I really want to know is can I daisy chain a power strip dedicated to my layour power off of a surge protector plugged into a wall outlet. The circuit is in fact a 15 amp circuit and the draw when I am running trains is less than 2 amps. My 2 circuit breakers are set for a 2 amp trip current.

Now, I know that you have not personally examined my layout, or my layout wiring or my house wiring. But you did appear to indicate in your first reply that daisy chaining the power strip may not necessarily be a bad thing. So, what do you think as opposed to what you know?

44

Personally I wouldn’t hesitate for a moment in running a powerstrip through a modular surge protector into a 15amp outlet. I have routinely run multiple powerstrips in adjacent plugs on those six-outlet ‘plug-in’ wall adapters that often feature ‘surge protection’ … but am careful to keep an eye on the potential peak draw if all the connected devices should be active at the same time. As I think you should, if you don’t already.

But then, I’m not a fire marshal. And I fell for the idea of whole-house surge protection for a while, too (and in the interests of fair disclosure, for that 1/8" polybutylene water-distribution system that mimicked electrical service – until I built a couple of spec houses that used it!) so I don’t claim superior knowledge about potential issues or failure modes.

45

Power strips plugged into power strips are always a no-no. No fire marshal will allow that if they sea it. It doesn;t matter if you only have a small load plugged into it, well withint he capacity of the strips, outlet, and circuit. The fact that it does allow you to have (let’s say you use 7 outlet strips) 49(!) things plugged into one outlet is what sets off the alarm bells. Actually, use 2 strips, plus a full 7 plugged into that one - that’s NINETY EIGHT things plugged into one wall outlet. Nope.

Especially in an office setting, where even if it’s 80 degrees, someone will be cold and bring in a portable heater. But it’s just s amall one - well, most of those small ones draw the same 1500 watts as a bigger one. The only thing you can count oin is a properly inspected wall outlet and circuit - that will trip the breaker on an overload and not burn down the building first. But power strips? Wha happens if you overload that (but not by enough to overload the circuit breaker for the wall outlet?)? Does it have a breaker that reliably trips? Does it just get hot and melt into the floor?

–Randy

46

Then I am ok I think. I do not run any other equipment when I am running trains. And the breakers trip, when I installed them I created a short and they did their thing.

Fair enough, Overmod.

47

Randy, what part of ‘carefully measure the peak load plugged into the strips’ seems to be too difficult to comprehend? Just because I have a hammer and 49 places to drive nails doesn’t mean I nail every one just because I can. There is still a place for common sense in this world, and what the Bear was (and is) talking about involves that common sense.

Of course, the original problem appeared to be just one power strip plugged into a separate surge module, which is hardly a fan-out extravaganza even for modern nanny-state types. I’m going to have to find out locally what the common-sense reason for banning that one was supposed to be.

48

Well, a single outlet surge protector is rather rare (I know they DO make them), so when I hear surge protector I think the kind that looks like a power strip…

I may not be dumb enough to overload the power strips, you may not be dumb enough to overload the power strip, no one reading this may be dumb enough to overload the power strips. But everyone reading this isn;t everyone - just read some social media posts. It’s happened, it’s caused fires, and is thus verboten by the fire code and/or electrical code. Even if there is exactly ONE 5 amp load plugged into a 15 amp rated pair of power strips, or power strip plugged into a surge protector, in a 15 amp outlet, thus posing exactly ZERO danger, it’s not what’s plugged in NOW, it’s that the potential exists.

I was just related a story today, a guy was working on replacing an overhead light. Turned off the wall switch, turned off the associated breaker. Verified the line was completely dead with a meter. Halfway through working on the light, another guy came in and said hey, the lights were all out, so I flipped that breaker on… No matter how careful YOU are, it’s the OTHER idiot that gets people hurt.

–Randy

49

Yep, that’s what “lockout-tag out” is all about, which obviously wasn’t followed.

Mike.

50

Randy, OMG.

51

I am not a licensed electrician, but I do some electrical work in my own house. For example, I recently installed two dozen LED recessed cans in my unfinished basement.

Like the guy in Randy’s story, I do turn off the circuit breaker in the service panel when I work on an active circuit. But if I thought that others would enter the workplace as happened in Randy’s story, I would take the extra precaution of disconnecting the hot wire from the switch in question.

Rich

52

BTW the guy in the story didn;t get shocked, the wall switch controlling the light was still off (and properly on the hot side, of a properly wired circuit - which is not always the case so it is not a reliable way to cut power), plus he was wearing gloves. The irony was he was showing a new guy how to do things safely.

I’m not sure anyone else in my house even knows where the breaker box is, so I feel pretty safe shutting off the breaker to work on things. ANd it’s too high for the dogs or cat to reach, so even if they wanted to off me, they couldn’t. [(-D]

I expect to be doing at least some of the work in reqiring my basement as I rebuild, but it will be checked by a licensed electrician and of course is subject to inspection. It will take longer if i DIY some of it, but it will save a bit of money.

–Randy

53

Agreed. If you really want to be safe cap off all the wires to the switch and isolate the switch.

Rich

54

Note that prior to 1937 he would have been safe no matter how incompetent his wiring might have been if he had used the old standard double switch (which interrupts both the hot and neutral conductors going to the fixture). Interestingly these were made illegal for new “licensed” construction, precisely because they might make the ignorant unwary in the assumption that a continuous-neutral fixture would be as safe to work on, when for a variety of reasons it is not.

A fun trait of licensed electricians in the portions of the South I have lived is to randomly change not only the polarity, but the wire color in intermediate circuit runs. I have to wonder if this was done in the same spirit as small-town Southern real-estate lawyering, since after all the ‘hoi’ aren’t supposed to be messing with licensed-electrician-only parts of the premise wiring, to penalize those so bold as to question the need for professional compensation in all respects. On the other hand, Hanlon’s razor shaves many of these situations rather well.

Can someone explain to me how to implement lockout effectively on house breakers, where there is no effective way to apply a lock either to the breaker or to the enclosure? And is there someone who has developed the tag equivalent of the Billups Neon Crossing Signal that can be applied and reapplied over breaker(s) that need to be off no matter how ‘helpful’ or inconvenienced other users of the premises may be?

There is an amusing side note to this, concerning mid-Seventies Cadillacs. These tended to be driven by a cohort which, shall we say, was often accustomed to getting their way ‘no matter what’ and not be inconvenienced, let alone yie

55

I’m thinking that if I could hear Overmod speak his posts in a James Earl Jones voice it would be really cool!

56

Hey Doug, how do you know that Overmod isn’t James Earl Jones?

I think that JEJ may be a model railroader. [:-^]

Rich

57

There are LOTO breaker lock out devices available:

LOTO_breaker by Edmund, on Flickr

Used to use them all the time,

Ed

58

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59

In a typical house the convenience circuits are 15 amps. These are located in the living room, the bedrooms and bathrooms and the garage. In the kitchen and the dinning room 20 amp circuits are required by code. These are higher amp circuits so that you can plug in appliances like toasters and electric frying pans.
The first thing I learned as an electrician is to always treat all installed wires as if they are hot. If you are doing new construction that has never been hooked up then that is one thing but any old work should always be considered hot. However if you are safe, working with hot circuits is no problem. That is why tools are insulated. One time we did a service call at a large truck dealer. They had a coffee maker that burned up. When we tried to figure out why the breaker didn’t trip we couldn’t even figure out which breaker it was. When we turned off the breaker it was supposed to be the wire was still hot. Finally after opening up every electrical box we found a junction box that someone had wire-nutted to different circuits together….
Also sometimes people will switch the neutral wire instead of the hot so turning off the light switch won’t stop you from getting shocked.
As for power strips, they have a lower amp rating than the house circuit. It is dependant on the wire size and the other components. It should be marked on it somewhere. The same with extension cords.

60

With or without the black helmet heavy-breathing effects?[A]

Thank you for not having brought up the Central Scrutinizer voice…

or invoking the Ronald McDonald of the nouveau abstruse…