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I agree 100% with Paul.  Using a polarized plug on a layout assures that all transformers are phased, even when too dark to see a red dot, or when someone else is running and doesn't think about the red dot.

 

It is a safety feature, because having transformers out of phase can cause some dangerous shorts & current flows on the low voltage side.  40 volts can give a tingle if your hands are damp, like from sweat.

 

Having said that, let me add that I repair transformers for MY layout.  If I were doing them for resale, I'd use a non-polarized plug unless a buyer specifically asked to match his/her existing transformer.

 

If the layout is fed from multiple receptacles, then one must check to determine if the receptacles are on opposite sides of the 220-volt line.

 

Tripleo:  household receptacles are never wired in series.  They are wired in parallel.  Use of white wire, with no marks, is a sign that your house was wired by an amateur.  Be careful!  The lack of a ground wire also entails some risk.

 

SW Hiawatha.  The postwar ZW can be wired either way.  Unless someone has tinkered inside or a wire has broken and is touching, the two wires are interchangeable, and there is nothing for a third grounding wire to connect to.  I I use 2-prong polarized plugs on my transformers so that they are always in phase.  My entire layout is fed from one 20-amp receptacle, which I know is wired correctly because I wired my house.

 

One can never assume that because a house was wired by a professional or was passed by local inspectors, that it is correct.  One of my sons bought a new house and I found the GFI in the kitchen was wired backwards.  Another bought an old house.  When we renovated the kitchen, I found the 20-amp outlets were fed from each end by different breakers.

Last edited by RJR



quote:
I have often suggested to folks that they should feel free to ask questions on this forum, but they are afraid they will be made to feel stupid,




 

I suppose it would have been better had nobody commented on your use of three prong plugs?

Maybe its just my opinion, but as a vendor, you have a responsibility to do things correctly.

I too give my vote to, Miss Susan. I'm "old school" I guess. When I replaced the cords on my Lionel Type Z's and ZW's I used heavy duty cords with two-prong, non-polarized plugs.

I then plugged my transformers into a heavy duty metal barrier strip with it's own power switch and a 15 Amp quick blow breaker. It still works great after 58 years. I bought it in kit form from, RS. (yes, all transformers are in phase)

My electrician installed surge protectors at my service panel. AT&T came out and installed surge protectors in their service entrance. All in all I think that I'm protected.

I do not wish in anyway to argue because I know you guys are all correct, what I do not understand is yes I can replace the entire cord, (even if it is not necessary) with a polarized cord, which I have seen be able to plug in backwards especially with extension cords, or I can put the 3 prong plug on which there is no way you can plug in backwards. And the criticism is why because there is no wire attached to the third prong? I'm very sorry, but other than it making interesting conversation, I am having a hard time justifying changing what has worked so well on over 40 transformers. Believe me when I tell you, much of the suggestions that have been made in the past I whole heartedly agreed with, so much so, that I have sent customers exchange equipment in order to get the incorrect equipment back, for which we provided return shipping labels. In this case however I am having a real problem seeing any potential damage.

 

The suggestion of making sure your surge protector is UL rated I think is great. Love that one! I think I will do some homework at Lowes/Home depot in order to make solid suggestions to the customer. It looks like other alternative stores are disappearing faster then the eye can see.

 

Sorry Susan, I absolutely agree you are technically correct, but for the user what difference does it make? Every transformer I have ever  seen is well insulated from the transformers primary connections.  There is nothing to ground there if you wanted to.

Originally Posted by AmFlyer:

Jon, the professionals I speak with, including at the utilities refer to the two hot leads in the breaker box as phases. In reality they are the two ends of a transformer secondary, plus the center tap neutral. The primary of this transformer is connected to one of the phases of a three phase distribution circuit. So it is a center tap single phase feed from the power company that seems to be referred to as two phases. May not be technically accurate, but it is in use. 

Thanks, Tom. The terminology can indeed be confusing. Lets agree that one of anything in not a phase, it requires two or more of something or event to achieve this. True, it's common that a single "hot" leg of a service be referred to as a phase. But this is not a single phase service, again, you need two to make a phase, hence, single phase.

 

I lifted this from wikipoopia:

 

In electrical engineering, single-phase electric power is the distribution of alternating current electric power using a system in which all the voltages of the supply vary in unison. Single-phase distribution is used when loads are mostly lighting and heating, with few large electric motors. A single-phase supply connected to an alternating current electric motor does not produce a revolving magnetic field; single-phase motors need additional circuits for starting, and such motors are uncommon above 10 or 20 kW in rating.

In contrast, in a three-phase system, the currents in each conductor reach their peak instantaneous values sequentially, not simultaneously; in each cycle of the power frequency, first one, then the second, then the third current reaches its maximum value. The waveforms of the three supply conductors are offset from one another in time (delayed in phase) by one-third of their period. When the three phases are connected to windings around the interior of a motor stator, they produce a revolving magnetic field; such motors are self-starting.

 

In North America, individual residences and small commercial buildings with services up to about 100 kVA (417 amperes at 240 volts) will usually have three-wire single-phase distribution. Larger consumers such as large buildings, shopping centers, factories, office blocks, and multiple-unit apartment blocks will have three-phase service.

A single-phase supply connected to an alternating current electric motor does not produce a revolving magnetic field; single-phase motors need additional circuits for starting

 

I take issue with that.  A series-wound motor has no additional starting circuit, and runs fine on AC.  For example, a Pulmor.

 

"Wikipoopia"?

Originally Posted by AmFlyer:

There is no safety benefit to a polarized plug on a plastic case transformer where no metal parts connected to the 120V side of the windings are exposed. Polarized plugs can be a nuisance if the transformer needs to be rephased. Household 240V service is generally referred to as two phase, the two power leads are 180 degrees out of phase when referenced the the neutral. In house wiring, the neutral (white) and ground ( bare or green) are not the same. 

 

My comments, generally applied in the US, and off course if there are any doubts one should consult a professional .

 

Generally agree on the polarized plug as well as a 3 prong plug on a ZW - doesn't hurt, other than giving the impression what little external metal there is on a ZW (base, lugs) is grounded.

 

Residential power is single phase, it just has two legs - 120 VAC on either side of neutral. Going from one leg to another = 240 VAC single phase.

 

As to neutral vs. ground, depends on how you define "not the same". At the panel they are the same - both run to the same bus bar (which is ground).

Our season is winding down now, and I plan on spending a lot of time, redoing our web site, with particular attention to our "tips and techniques" section. I think it is very important, to while using the KISS system, the information must be technically correct, and abide by all safety standards.
The section is dedicated to those who may not have had a lot of personal layout or electrical experience.

As a result of this discussion, we have picked up some important items for the people who perhaps do not have your guys experience:

 

1. One way or another multiple transformers must be in phase.

2. It is strongly recommended that all 110 volt gear for our layouts should be plugged into a single good quality power strip with a surge protector. Preferably with room to plug in up to 6 different devices.

3. The surge protector should be a name brand, preferably made of metal, and with a UL certification.

4. The surge protector will make life a lot easier if it has an on/off switch.

 

My conclusion:

 

The use of polarized 2 prong cords with molded in plugs is certainly an option, but how doth one insure that all transformers are then in phase? If by using the 3 prong plug with a 2 wire cord routine, the worst you have to do is reverse the black and white terminals on the plug.

Enough said, time to move on, am truly grateful for all your comments, sometimes out of chaos comes some pretty good order.

Gilly, final question, promise. I have heard of guys installing protective devices in engines, extra fuse holders after etc. In your very much educated opinion, if you opt for a top quality surge suppressor, like the ISOBAR 6 or 8, is anything else really necessary? I suspect most people I will be dealing with are pretty much old school operators.

To AM Flyer....My understanding of having transformers in phase means that the point of connection to the windings of the transformers should be the same relative direction on all the transformers. If it is reversed the flow in the transformer will reverse and therefore throw the outputs of the transformers 180 degrees out of phase vs the first. Is this correct? Not that it really matters for our purposes, just curious. so who's on first?

TinMan, yes. Correctly installed, polarized plugs facilitate proper phasing of multiple transformers. The issue that can sometimes occur is having outlets accessible from the layout that are fed from opposite sides of the breaker panel. These outlets are then 180 degrees out of phase with each other, requiring the transformer plugs be reversed in one of the outlets to have the transformer secondaries in phase. 

 

quote:
Point taken, 110v power tool shorting out laid on tracks, broken light bulb etc.



 

Surges can be created locally on the train layout that has nothing to do with 110 volt tools being laid on the tracks.

Derailed trains can cause surges. So can doing something as simple as operating a milk cars, which involved energizing and de-energizing a solenoid. 

There have been extensive threads specifically on the use of circuit breakers and surge suppressors on the low voltage side of the transformer.

 

Here is a short one

And another

This four pager goes into circuit breakers and TVS

 

If you do a search on TVS, you will get many results.

Last edited by C W Burfle

SAL9000, you are correct about the "legs", I was just pointing out that legs are now referred to as phases by many people even though it is not technically correct. The neutral and ground wires perform different functions and should not be connected at a load. GFCI's can perform their safety function because as you said the neutral and ground are only connected at the breaker panel. 

Tinman3rdRail,

 

Whether you go with a 3 prong plug which is polarized (not my first choice like Susan stated), or a 2 prong polarized plug, the phasing correction would be the same, you need to reverse the wires at the end of the wire if it is out of phase.

 

Both plugs would only let you plug in the cord one way consistently which is what you want for your customers.  I would match up the phasing with a modern transformer in advance since post war transformer don't care how you wire it.  Your customers should be good as long as they don't cross over to the circuits on the other side of the panel which shouldn't happen if in the same room, but you never know. 

 

It will always be in phase with everything in the same powerstirp, outlet, or on the same side of the panel with other outlets (again, you never know if someone messed up wiring an outlet).  Usually whole rooms are all on the same circuit or same side of the panel and for most people, this will work great.

 

Using a powerstrip in one socket of an outlet, you can plug in multiple transformers and you are guaranteed they will all be in phase with each other if you "pre-phased" the post war transformer correctly to a modern one.

 

Always have UL powerstrip over some no name one that hasn't been tested, but really its for convenience again for me.  Yes, metal is better than plastic, but I have used both.

 

Sounds like you have a plan of attack for your customers to make theirs and your life easier.

 

 

 

 

 
 
 
 
Last edited by pmilazzo
Originally Posted by TinMan3rail.com:
 Sorry Susan, I absolutely agree you are technically correct, but for the user what difference does it make? Every transformer I have ever  seen is well insulated from the transformers primary connections.  There is nothing to ground there if you wanted to.

Please accept my comments as constructive.  There's no reason for you to change the 3 prong plugs that have already been sold.

  The best "wiring convention" for postwar transformers would #16 lamp cords with two-prong, non-polarized plugs.  Polarized 2-prong plugs on all of one owner's phased transformers do the same job as the 3 prong plug you used.

   The  Polarized 2-prong plugs will look more professional for restorations and replacement polarized plugs can be easily rewired for phasing if needed.

MaleCordCap

General information:

The ground plug is for use only with grounded equipment.
A 3 prong replacement plug costs more than a 2 prong polarized replacement plug (male cord cap).
For personal use, a 3 prong replacement plug (from a junk box) is fine as long as the round grounding prong is not connected to anything.

Re: Electrical Code and polarized or non polarized replacement plugs/cords.
Non polarized plugs (with 2 narrow blades) are still sold as replacements for older items.
Replacement polarized plugs can be easily rewired for phasing if needed.

Re: Phasing transformers and the building electrical panel.
When I wired my Run Room I set it up so all the duplex receptacles feeding my layout  would be on the same phase of my 240 V building panel.  I always wondered if that was true so I just confirmed that it is true with a test in my basement.  All transformers should be connected to the same electrical panel phase.  My layout uses 3 15A circuits and they are all on the same panel phase.

 

Originally Posted by tripleo:

Recently replaced a wall receptacle here in the house on the hill because I wanted one that the plugs run out the side parallel to the wall instead of straight out.

 

Took the old one off (a two slot, no ground receptacle) and found one white wire running to the positive and the same white wire running from the negative and off to parts unknown. I assume, being a complete idiot at this stuff, that the whole circuit is wired somehow in series? 

 

Regardless, I figured that the worst that would happen is that I would burn the house down, so I installed the new outlet (complete with three pronged receptacles; the ground being connected to nothing) plugged in a small TV, lamp and train transformer.

 

So far, so good. The light lights, the TV has a picture and the train runs.

No, the worst that would happen is electrocution to you, a family member, or a service person anywhere in your house.

Originally Posted by Susan Deats:

......Re: Phasing transformers and the building electrical panel.
When I wired my Run Room I set it up so all the duplex receptacles feeding my layout  would be on the same phase of my 240 V building panel.  I always wondered if that was true so I just confirmed that it is true with a test in my basement.  All transformers should be connected to the same electrical panel phase.  My layout uses 3 15A circuits and they are all on the same panel phase.

 

 

Susan,

 

Thank you for confirming this.

 

Jim

Background with phasing transformers and rewiring:

The postwar ZWs on my first layout were phased to one plug strip and with all plugged in one side was spray painted with silver paint.

As transformers were rewired the new ribbed wire and smooth wire were matched to the placement of the original ribbed wire and smooth wire.

My first Z4000 turned out to be in phase with all my postwar transformers.  Most of my new transformers and "bricks" have been in phase with existing.

The first time I used Polarized 2 Prong Plugs on postwar transformers was with a modular layout where paint on the plugs would be inadequate.  The two prong polarized plugs were a must in that situation.

Susan, I do not disagree, but tinman has a point:  the plugs he uses allow an owner to rephase a transformer.

 

Tripleo:  Mistake to install a 3-prong receptacle not connected.  Gives a false sense of security.  I recommend that you install several smoke detectors on each floor of your house.  I also recommend you check with a professional to see if installing GFI breakers in your breaker box (if you have one, vice fuses) will provide any measure of protection.  You might also check, if you have any 3-prong receptacles elsewhere, whether they have a green wire connected to the ground prong.

Hopefully Susan Deats will comment about this:

 

While surfing around the Net, I found several references to installing a GFI outlet in  locations where there is no available ground. In these cases, the GFI outlet must be labeled:  "NO EQUIPMENT GROUND".

 

I found one article that just recommended running a wire from the ground terminal of the outlet to a screw inside the electrical box. Trouble is, that will only work if you have a metal electrical box that is grounded. My parents had a 1950's house that was mostly wired with non-metallic cable without a ground wire. The house had metal boxes. So there was no ground in most of the house. Only the kitchen, bathroom, and basement circuits had ground wire.  I guess the moral of the story is "don't believe everything you read".

 

By the way, I don't think you will find them at Lowes, Home Depot or even your local hardware store, but 2 prong outlets (no ground) are still available. I had occasion to look for one recently.

Last edited by C W Burfle
Originally Posted by TinMan3rail.com:

Gilly, final question, promise. I have heard of guys installing protective devices in engines, extra fuse holders after etc. 

Surge suppression works best in a layered approach. The ISOBAR will provide excellent protection for the devices that are attached to it.  

 

Looking on your website I see that you are offering the Lionel 275W ZW. When using these older transformers, additional protection on the load side is a must. Having a second layer of surge suppression is always a good idea.

 

I apologize for the delay in responding. It took me some digging to find this. Scott's Odd n Ends was sold. But, found it....

 

TVS-4 

 

Wire this between your transformer and the track.

 

Gilly

Last edited by Gilly@N&W

I'm not sure if this has been addressed before, but I'd be a little worried about recommending a six outlet strip for the use of ZW's or Z4K.  While, perhaps, most people will never be running six large transformers at anywhere near full load, I've seen enough pictures on the forums here, of layouts with more than that, to be worried.  

 

6 ZW's or 5 Zk4's could put a single 15 amp circuit at full load, and lets be honest, we all have several smaller transformers and wall warts hooked up as well to feed lights and command bases and whatever else.  Add to that the rooms lights and anything else that may be plugged in in the circuit, and it becomes very likely you could over load a single 15 amp circuit.  Now, of course the breaker should just pop in the event of an over load, but it still doesn't seem like good practice to plug more into a line than it can handle.  

 

I recommend knowing what else is on the circuit you plan to use to power your transformers, and trying to spread the load across several circuits if you don't have access to a dedicated line.  This, of corse, leads to needing to be able to easily re-phase your transformers, as the circuits you have available may be out of phase with each other.  How that should be accomplished? I'd prefer my refurbished transformers to have non-polarized plugs, however using two prong polarized wouldn't bother me as long as they are matched to say a powerhouse or some such.  I understand using the grounded plug for ease of changing the polarity, but beside from the concerns of hooking three pins to two wires, and giving the impression something is grounded, my primary concern with this is it just looks bad.  When wandering a swap meet, I stay away from transformers with such plugs, as they give the impression that someone liked to tinker, and I have no idea what's going on inside the case, or what else may have been done. 

 

"Just because something doesn't do what you planned it to do doesn't mean it's useless."  -  Thomas A. Edison

I have everything- transformers, bricks, Legacy Base, phased and plugged into a Belkin 10 outlet switched and fused power strip recommended by an electrical contracter. That strip is plugged into another Belkin strip along with various SC-2s etc. This is then plugged into a dedicated 20 amp circuit installed specifically for layout power. Outlets in the support poles that are in the middle of the layout 4 in one 2 in the other supply all power to the layout and nothing else.

It's been this way for years now.. I can walk in the room and hit one switch and everything comes on and also everything is off with one switch. Don't know if its right but sure is convenient.

Last edited by RD

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