Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Electrical Question

1551 views
21 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    January 2017
  • From: Southern Florida Gulf Coast
  • 18,255 posts
Electrical Question
Posted by SeeYou190 on Thursday, January 31, 2019 9:00 AM

Up front... I am probably overthinking this.

.

On my layout, I will have a 20 AMP supply coming from the breaker on a dedicated outlet for the layout.

.

I was told that it is OK to use 15 amp electrical outlets in the legs of the layout on the 20 amp circuit.

.

I plan to simply daisy-chain all the outlest together, but I am afraid I might cuase an unsafe condition. If I have more than 15 amps passing through the metal connector on the 15 amp outlet, will that create a problem?

.

Do I need to wire-nut the wires together and use a short lead to the outlet to prevent this?

.

I hope this drawing explains my concern.

.

.

-Kevin

.

Living the dream.

  • Member since
    June 2003
  • From: Culpeper, Va
  • 8,204 posts
Posted by IRONROOSTER on Thursday, January 31, 2019 9:10 AM

No.

Your circuit is protected by a 20 amp circuit breaker so all your outlets should be 20 amp also. 

You may think that you'll keep the load down, but my experience has been that it is very easy to overload a circuit with too many devices - lamps, power packs, tv's, etc.

I'm not an electrician, but I'm not sure that hanging outlets on your layout legs wired into the house current meets code or is safe.  Personally, I would find another way to do it.

Paul

If you're having fun, you're doing it the right way.
  • Member since
    January 2009
  • From: Bakersfield, CA 93308
  • 6,526 posts
Posted by RR_Mel on Thursday, January 31, 2019 9:24 AM

Kevin
 
18 amps is an awful lot of current at 120 volts.  Are you talking about amps at 120 volts or 12 volts?  18A x 120V= 2160 Watts, 18A x 12V=216 Watts.
 
 
  
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Thursday, January 31, 2019 9:34 AM

I'm no electrician, but aren't room outlets that are on one circuit wired like Kevin's drawing?  daisy chaining around the room?

When you look at the instructions on the box the outlet (actually receptical) come in, that's what it shows you.

Where's our resident electricians when we need them?  OH yea, they might be working!

Mike.

  • Member since
    August 2013
  • From: Richmond, VA
  • 1,890 posts
Posted by carl425 on Thursday, January 31, 2019 9:42 AM

I also am not an electrician, but...

15-amp outlets are rated at 20 amps pass through.  The 15 amp rating applies to the device plugged in to the outlet.  A device that draws more than 15 amps will have a plug that will not fit in your 15 amp outlet.

I have the right to remain silent.  By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.

  • Member since
    July 2006
  • From: North Dakota
  • 9,592 posts
Posted by BroadwayLion on Thursday, January 31, 2019 9:56 AM

All of the outlets provide the full amperage that your house circuit is wired for.

Your concern is on the 12v side of the system.

Nonetheless Amperage is something that your equipment draws from a circuit, you can have 20 amps on your track circuit (Like the LION does) but a trainstill draws less than one amp. When I have all ten trains running at once my draw is still less that 10 amps. Now if you put a quarter on my tracks all 20 amps will pass through that circuit, and I have burned up more than one resistor on my layout.

Your equipment decides how much amperage to draw. Real Subway Trains can draw on almost unlimited amperage although each car is fused for 600 amps. Actually when accelerating the draw is 300 amps per car or 3000 amps per trains. And how many trains might be on the same circuit at the same time. We are talking real power here.

 

 

We have three 100 amp fuses out on the power pole, but that is at 4000+ volts. Avter it has been delivered to our transformers we have thousands of amps at 110 volts.

Your transformer or power supply is limited to its design capibilities and is fused (or provided with a circuit breaker) accordingly. Typically 1 to 3 amps. Put a quarter on your tracks and it will try to draw maybe ten amps, maybe more, but your circuit breaker says, nothing doing.

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

  • Member since
    November 2016
  • 476 posts
Posted by j. c. on Thursday, January 31, 2019 11:06 AM

put simply your drawing anta gona work , your trying to draw 36 amps on a 20 amp breaker .a 15 amp outlet means 15 amps load can be pulled from it but  safety standards  limited load to 80% of rating .

  • Member since
    January 2017
  • From: Southern Florida Gulf Coast
  • 18,255 posts
Posted by SeeYou190 on Thursday, January 31, 2019 11:40 AM

IRONROOSTER
Your circuit is protected by a 20 amp circuit breaker so all your outlets should be 20 amp also. 

.

Using 15 amp outlets in a 20 amp circuit is approved by NEC. I only question the ability of a 15 amp outlet to pass through 20 amps on the connection built into the outlet.

.

IRONROOSTER
I'm not sure that hanging outlets on your layout legs wired into the house current meets code or is safe.  Personally, I would find another way to do it.

.

Perfectly safe, and designed for it. NEC approved and industrial ANSI rated.

.

.

RR_Mel
18 amps is an awful lot of current at 120 volts.

.

I seriously doubt the layout woulf ever pull more than 5 amps. I just want to avoid ANYTHING dangerous. John Allen's GORRE AND DAPHETID died in an electrical fire. I do not want the STRATTON AND GILLETTE to be in the same danger.

.

mbinsewi
Where's our resident electricians when we need them?  OH yea, they might be working!

.

Yeah, I should have posted this question in the evening hours.

.

carl425
15-amp outlets are rated at 20 amps pass through.

.

It sounds like it is OK if this is true. Thank you Carl425.

.

j. c.
put simply your drawing anta gona work , your trying to draw 36 amps on a 20 amp breaker

.

In my example I am drawing 18 amps. I will never use this much current. I need to know if this situation occurs due to equipment failure or something else I do not create a fire hazard.

.

Please, someone with electrical (NEC) knowledge look at the drawing in the first post and let me know the answer. If you need additional clarificaion just ask.

.

If I need to use wire nuts and short stub connections at each outlet I will, but I prefer not to.

.

-Kevin

.

Living the dream.

  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Thursday, January 31, 2019 11:52 AM

I'm sure Sheldon will be in later, he'll know, or Ed (7j43k), I haven't seen him around in a while.  I hope all is well.

Mike.

  • Member since
    January 2009
  • From: Bakersfield, CA 93308
  • 6,526 posts
Posted by RR_Mel on Thursday, January 31, 2019 12:11 PM

Your OK with your drawing, I was worried about you actually drawing that much current for your layout.  I’ve got all kinds of electronic stuff on and around my layout and with everything on at the same time it would be well under 10 amps at 120 volts.
 
 
EDIT:
 
According to the John Allen site the problem was with the heater.  John had the ducks blocked and someone turned on the thermostat causing the furnace to come on when no one was there.
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
  • Member since
    January 2017
  • From: Southern Florida Gulf Coast
  • 18,255 posts
Posted by SeeYou190 on Thursday, January 31, 2019 1:10 PM

RR_Mel
According to the John Allen site the problem was with the heater.  John had the ducks blocked and someone turned on the thermostat causing the furnace to come on when no one was there.

.

The Fire Inspectors report blamed it on the wiring for the layout. The story about the heater came from someone that was operating the layout.

.

We will never know for certain, but fire scares the living daylights out of me.

.

-Kevin

.

Living the dream.

  • Member since
    April 2011
  • From: About 20 minutes from IRM
  • 430 posts
Posted by CGW121 on Thursday, January 31, 2019 1:17 PM

I had a conversation with someone who was a friend of Allen. He had a space heater than he turned off when things were done. After his brother took over that task was forgoten and an electrical cord overheated and started the fire. But details are unimportant in reality.

 

  • Member since
    January 2015
  • From: Southern California
  • 1,682 posts
Posted by Lone Wolf and Santa Fe on Thursday, January 31, 2019 1:20 PM

   Kevin, I am an electrician. Using 15 amp receptacles is fine unless you know that you are going to plug in something that is over 15 amps into a single receptacle. A heat gun is about 12 amps. So is an electric heater.
    The only thing I can think of that you might plug in with higher amps is an air conditioner or a microwave. You should have a separate circuit for that if it is a large unit.
    If you are going to plug in a heater and a heat gun at the same time you will overload the circuit.
   By the way. For 20 amp circuits you must use #12 size wire. The circut breaker is always based on wire size used.
    So my question is, what are you planning to to plug in that is 9 amps? If you know everything that you are planning to use at once then you can add them all up and see what the load is.
    If you have any concerns about 20 amps not being enough then simply have two 20 amp circuits installed. It is the same amount of work as a single curcuit.

Modeling a fictional version of California set in the 1990s Lone Wolf and Santa Fe Railroad
  • Member since
    February 2015
  • From: Ludington, MI
  • 1,826 posts
Posted by Water Level Route on Thursday, January 31, 2019 1:23 PM

carl425

I also am not an electrician, but...

15-amp outlets are rated at 20 amps pass through.  The 15 amp rating applies to the device plugged in to the outlet.  A device that draws more than 15 amps will have a plug that will not fit in your 15 amp outlet.

 

I'm also not an electrician, but did complete my own wiring on a 500 sq ft home addition a few years ago (12?) with the aid of plenty of reading, and access to several electricians at work.  As I recall, yes you can have 15 amp receptacles on a 20 amp service, and yes daisy chaining is fine with the exception of the ground wire.  That must be pigtailed.  There also must be more than one receptacle too, although local codes may limit the total number.  The concept being that you will not pull that much current from a single receptacle.  However, if you are putting in a dedicated 20 amp circuit for say a dishwasher/microwave/window air conditioner and there will only be the single receptacle on the circuit, then the receptacle must be a 20 amp receptacle.

Mike

  • Member since
    January 2015
  • From: Southern California
  • 1,682 posts
Posted by Lone Wolf and Santa Fe on Thursday, January 31, 2019 1:27 PM

CGW121

I had a conversation with someone who was a friend of Allen. He had a space heater than he turned off when things were done. After his brother took over that task was forgoten and an electrical cord overheated and started the fire. But details are unimportant in reality.

 

 

It was probably an extention cord. Unless you buy a cord with the proper size wire then you shouldn't use one with a heater. Most indoor extention cords use #16 size wire which is too small. And since the circuit breaker is for #14 or #12 wire it won't trip to avoid a fire.

Modeling a fictional version of California set in the 1990s Lone Wolf and Santa Fe Railroad
  • Member since
    January 2017
  • From: Southern Florida Gulf Coast
  • 18,255 posts
Posted by SeeYou190 on Thursday, January 31, 2019 3:57 PM

Lone Wolf and Santa Fe
  So my question is, what are you planning to to plug in that is 9 amps? If you know everything that you are planning to use at once then you can add them all up and see what the load is.

.

Nothing, I think the whole layout might draw less than 5 amps. My only concern is that IF something went wrong and the entire circuit was drawing 16-18 amps, would the first receptical in the daisy chain be under-capacity.

.

It sounds OK.

.

-Kevin

.

Living the dream.

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,280 posts
Posted by richhotrain on Thursday, January 31, 2019 4:08 PM

Lone Wolf and Santa Fe

   Kevin, I am an electrician. Using 15 amp receptacles is fine unless you know that you are going to plug in something that is over 15 amps into a single receptacle. 

I am not a licensed electrician, but I have done some extensive residential wiring around my house. I agree with Lone Wolf and Santa Fe that 15 amp outlets can be used on a 20-amp breakered circuit. But, then, you gotta use 12 gauge wire.

So, why not just use 14 gauge wire and a 15 amp circuit breaker, Kevin? Or, use 20 amp outlets on the 20 amp circuit.

Also, your wiring diagram is correct. You simply daisy chain the wire from one outlet to another to another.

Rich

Alton Junction

  • Member since
    January 2017
  • From: Southern Florida Gulf Coast
  • 18,255 posts
Posted by SeeYou190 on Thursday, January 31, 2019 4:29 PM

Rich, 

.

I will be using 12 gauge wire everywhere. I build for the worst possible possibility.

.

One day I might have my Jazzy Chair plugged in recharging, a vacuum cleaner, and a space heater all at the same time. Maybe even a cappucino machine to boot!

.

I always believe in safety first, and I am wary of electricity.

.

-Kevin

.

Living the dream.

  • Member since
    August 2015
  • 62 posts
Posted by Sparky Rail on Thursday, January 31, 2019 5:48 PM

Kevin-

Electrician and electrical inspector chiming in here. Your plan is fine. I understand your concern that the outlet itself will be the weak link in the system, but if you look closely at a 15 amp outlet and a 20 amp outlet, most times they both use the same metal parts anyways, with the major difference being the 20 amp outlet will have the "T-slot" to allow for a 20 amp plug. I would advise you to use a "commercial grade back wired" outlet. They are more rugged than a standard residential grade and will hold up better to the repeated use they will see on your layout legs (I've been following your other thread!) They also will accept the #12 wire inserted the back, and the connection will be made by tightening the side screw to compress the wire very securely. They cost between $2-$3 each and are very much worth it. Finally, alot of electricians would join the incoming and outgoing wires together with a pigtail coming off to feed the outlet, so that any downstream current does not flow thru the outlet, but with a commercial grade outlet and the stranded wire you are using you'll be fine without that step.

I'd also like to thank you for your test layout thread. Watching your progress inspired me to get going with finishing my train room in my basement, which has been just an unfinished junk filled room in the basement for far too long!

 

 

 

  • Member since
    November 2016
  • 476 posts
Posted by j. c. on Thursday, January 31, 2019 5:59 PM

you drawing is fine if you are not trying to draw that amprage , if you do experance a short the braker will kick . if i were doing it i would use a groung fault braker or the first outlet as a gfi  . and don't go cheep on the outlets and get the ones that don't have screw connections on the side , IMHO i don't like the srtip and stick. i had a federal high voltage card for years and you are right on safety first , seen several guys bit the big ine from cheating on things.

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Thursday, January 31, 2019 8:22 PM

 As has been stated - this is EXACTLY how the outlets in your walls on each branch circuit are wired. Daisy chained together. There aren;t multiple home runs back to the breaker from each outlet. There's nothing wrong with using 15 amp outlets on a 20 amp circuit - probably have some of those in your house already as well. The reverse is ABSOLUTELY NOT SAFE - putting a 20 amp outlet on a 15 amp breaker. NEVER EVER do that.

 Better than just a GFCI is a combined GFCI/AFCI. The GFCI protects YOU from shocks by sensing current leakage to ground, the AFCI sense dangerous arcing conditions that can cause fires. 

 If the layout just plugs in to the wall, even though you have outlets all along it, it is considered a temporary device, so a lot of this stuff is not required - but it makes good sense to use it. If you permanently tie the layout to the circuit, then you definitely need to follow all current codes. The NEC has required AFCI outlets in certain locations for 4-5 years now. 

 I am not an electrician but I have done some wiring in homes I've owned, and a lot of this information is available by doing some searching.

 I doubt you will come close to drawing the full 18 amps with the layout. Very few things draw 9 amps at 120VAC. Even a power supply capable of 50 amps at 12 volts full oad, if it's only 80% efficient (pretty poor for a modern power supply, actually), it woudl draw about 6.25 amps on the 120V side. 50 amps - that's a lot of trains, structure lights, LED strip lights for layout illumination. Ot 10x 5 amp power supplies, same efficiency, would be the same total load on the 120V side. 

 Even running heavy power tools during construction - unless you will have helpers so multiple heavy duty power tools will be running at the same time. Even then - hitting 18 amps is a bunch of equipment running.

                                         --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    January 2017
  • From: Southern Florida Gulf Coast
  • 18,255 posts
Posted by SeeYou190 on Friday, February 1, 2019 6:38 AM

Randy,

.

Thank you for that response. That answers all of my questions.

.

I figured it was all A-OK the way it was planned, becuase that is the way my electrician told me to do it. I am paying him for right answers, I should assume he knows what he is talking about.

.

Like I said, I thought I might be guilty of over-thinking the whole situation.

.

The moderators moved this post to "Electronics and DCC" even though it is about neither electronics nor DCC. Interesting. I debated putting it in "Layout Building", but I guess that would have been incorrect also.

.

-Kevin

.

Living the dream.

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!