Outlets discussion

[TimePeace]

As the title says, this is reposted - but at the end of a very long thread and I thought it worth putting here. If any moderators disagree, feel free to remove.

To me the bottom line is, whether it is a 15 amp or a 20 amp circuit, if an overload is placed on it from one or multiple receptacles, the breaker will pop.

So the fact is, unless the circuits are improperly installed, any electric kettle that draws more current than the circuit can provide will pop the breaker. It does not matter how much the appliance draws (or tries to draw). The breaker will allow only so much to pass and then that's it.

I'm surprised that someone thinks a kettle might draw up to 32 amps - if that were the case, it could not legally have a plug attached to it that could plug into a standard household receptacle.

Any such device is required to have its current draw on the label. I just looked at my Wal-Mart kettle I use every day - got it at a yard sale - and it draws 1500 watts which at 120 volts translates to about 12.5 amps.

Now, I am not sure of the practicality of using an electric kettle on a moving train in a coach seat. But I would have no concern about it being an electrical risk.

I am an electrician btw, in a boat yard.

Edit: I am in awe of Amtrak's electrical systems. I pay attention to them when on the train and also when looking at the connections between cars. My sense is, no matter how often you get a bad car attendant or dining room staff, you will not have to worry about a bad electrician - and if there is a problem, a car will be bad ordered. Yes things do go wrong, but not because of a bad design or installation.

These guys are real professonals.

 

[Ryan]

What are the outlets rated for? 15A?

 

[benjibear]

Nothing over rated over 15 amps can have a standard plug. It is rated over 15 amps but less than 20 amps it can have a 20 amp plug. I can't remeber if the receptacles on Amtrak are rated 15A or 20A. Even if they are rated 15A, they may be on a 20A breaker. But I have to assume that there are many receptacles on one circuit. Building electrical systems would only allow a maximum of 13 receptacles on a 20A circuit. How many pairs of seats are on a car? 32? 32/13=2.5 so there would need to be at least 3 circuits in one car. If it was my design, it would be more.

Probably not an issue of electrical unless everyone on the circuit is using electricity. Cell phone chargers, laptops, etc. don't draw that much.

As far as safety, I don't think it would be a good idea. The possiblility of spilling something, getting burned, making a mess, etc. while probably rare is possible. I just don't think it was a good idea and it was not Amtrak's intent of the receptacles.

Oh by the way I am an electrical (and fire protection) professional engineer. When I first graduated I wanted to work in the rail industry but things never worked out. I would love to see plans of the some of the amtrak equipment but not sure how easy that is to obtain.

 

[Phil S]

Nothing over rated over 15 amps can have a standard plug. It is rated over 15 amps but less than 20 amps it can have a 20 amp plug. I can't remeber if the receptacles on Amtrak are rated 15A or 20A. Even if they are rated 15A, they may be on a 20A breaker. But I have to assume that there are many receptacles on one circuit. Building electrical systems would only allow a maximum of 13 receptacles on a 20A circuit. How many pairs of seats are on a car? 32? 32/13=2.5 so there would need to be at least 3 circuits in one car. If it was my design, it would be more.

Probably not an issue of electrical unless everyone on the circuit is using electricity. Cell phone chargers, laptops, etc. don't draw that much.

As far as safety, I don't think it would be a good idea. The possiblility of spilling something, getting burned, making a mess, etc. while probably rare is possible. I just don't think it was a good idea and it was not Amtrak's intent of the receptacles.

Oh by the way I am an electrical (and fire protection) professional engineer. When I first graduated I wanted to work in the rail industry but things never worked out. I would love to see plans of the some of the amtrak equipment but not sure how easy that is to obtain.

Hey bear, AFAIK the 13 is an often-heard urban legend, at least for residential in the US. It may be in NEC for commercial somewhere but I'll bet $50 it's not part of residential code. Elaborate rules about spacing between receptacles, counter tops, etc etc. but no actual limit on number of recptacles. Quote me code and I'll buy you dinner some time, when we're not already getting pre-paid meals on Amtrak!

 

[J-1 3235]

Hey bear, AFAIK the 13 is an often-heard urban legend, at least for residential in the US. It may be in NEC for commercial somewhere but I'll bet $50 it's not part of residential code. Elaborate rules about spacing between receptacles, counter tops, etc etc. but no actual limit on number of recptacles. Quote me code and I'll buy you dinner some time, when we're not already getting pre-paid meals on Amtrak!

I can't quote you the exact article (because I don't remember, and my code book is in the truck), but when doing load calculations (commercial or residential), you must figure 180 watts per receptacle. A 20 amp circuit has 2400 watts available (120 volts times 20 amps), 2400 divided by 180 is 13.3. So 13 receptacles per circuit.

As this is an Amtrak forum, not an electrical engineering forum, I'll leave it at that

Mike

 

[benjibear]

Probably in article 220. I think the handbook may even have an example. I have never put 13 devices on a circuit. I usually try to limit it to 8 and often less but really depends on the application.

 

[me_little_me]

Ah! Our outdated electrical code which assumed 60 and 100 watt light bulbs (or even 3 60s in a fixture). It never envisioned 13 watt fluorescents and zillions of low wattage cell phone chargers. What will we do in the future with one 15A circuit powering most of the (LED) lights in your house and the need to have six-plex outlets for all the chargers?

Similarly, I wonder how much power is really drawn by Amtrak's seat outlets even with all the laptops. Then again, they mostly use fluorescents (and probably LEDs in future cars) along with high efficiency A/C, refrigerators and freezers and convection instead of old fashioned standard electric coil stoves.

 

[X]

The code doesn't apply to the railroad.

The California and Surfliner cars both have two 20A GFCI circuits for the outlets at passenger seats, one for each side of the car. I believe the Superliner coaches have a very similar arraignment, I can't speak to the sleepers or other cars.

Edit: I am in awe of Amtrak's electrical systems. I pay attention to them when on the train and also when looking at the connections between cars. My sense is, no matter how often you get a bad car attendant or dining room staff, you will not have to worry about a bad electrician - and if there is a problem, a car will be bad ordered. Yes things do go wrong, but not because of a bad design or installation.
These guys are real professonals.

...

 

[benjibear]

I figured the NEC doesn't apply for the railroad.

I bet with diversity of the loads the draw will not be more than 10 amps, probably less. A peak usage probably is maybe twice that but that would be an exception.

 

[Phil S]

I think we all know that NEC doesn't apply to railroads. As for Article 220, yes, that's where I;d expect some limit to be found, but I don't think there's anything there. The relevant part of the article deals with how to calculate loads based on building square footage but not with how many receptacles per branch circuit. As I said, this idea of a limit comes up very often in electrical forums and is, I'm pretty sure, just an urban legend. That said, I agree, something like 8 is very reasonable good practice. Back to Amtrak?

 

[Ryan]

Look again, everything you need to calculate the limit is in there in 220.

And while it doesn't likely apply to Amtrak, it is a decent starting place for a standard, and it is adopted as the residential code in many, many places.

 

[TimePeace]

Look again, everything you need to calculate the limit is in there in 220.

And while it doesn't likely apply to Amtrak, it is a decent starting place for a standard, and it is adopted as the residential code in many, many places.

ABYC Marine standards are based on NEC (which for those that think we are saying Northeast Corridor, we mean National Electrical Code.)