New layout concerns

[rrswede]

After attending a local train show 4 years ago, I cobbled together a 4' x 8' 027 tubular layout using my childhood prewar equipment. I am now planning an L shaped layout composed of 3 ea. 56" L x 52" W sections. None of the rolling stock or locomotives are newer than 1950. I plan to utilize at least 3 ea. 90 watt 1033 transformers (original 60 watt 1041 is a spare) to power 2 separate loops and the accessories. For the present, I plan to use track power to activate various 1121 and 1122E turnouts in each loop and employ isolated track sections to activate various accessories on both loops. I consider this layout to be small in nature and plan to use 16 ga. (is 14 really necessary?) stranded wire for 3 ea. dead end L shaped busses with crimped quick disconnects between each layout section for disassembly and moving, 20 ga (strand or solid?) for the drops and Scotchlok 950 IDC connectors. I am aware of the relay issues with the 1122E turnouts and the controversies surrounding the IDC's. What other areas of concerns can you point out to me before I proceed?

 

Thank you, Swede

[lionelsoni]

The 1033 circuit breaker should trip around 5 amperes; so, as far as safety is concerned, even 20 AWG would not be too small.  The only reason for using heavier wire would be to reduce voltage drop in the track.  A CTT investigation a few years ago found that most track types are approximately equivalent in resistance to 16 AWG wire.  This implies that 16 AWG feeders are about the smallest that would be helpful in reducing voltage drop and suggests that 14 AWG or smaller is what you should use to get a significant effect.

The smallest building wire is 14 AWG, which is therefore easy to find at home-improvement stores, stranded or solid, and in a variety of colors.  It may well be cheaper than any 16 AWG you can find.  Stranded and solid wire are indistinguishable electrically.  It's completely a question of which you prefer to work with.

[David Barker]

Why not pick up a Kalmbach book on wiring?  It is an excellent reference and reasonable cost.

[rrswede]

Thank you for the input, Bob and Dave, and Dave, I do hope surgery today was fully successful and that you have a complete and rapid recovery. Bob, I have read some of your comments in this forum regarding the use of 14 AWG wire as power feeds. How do you determine when this is required?

 

Thanks again, Swede

[phillyreading]

The ratings for a; # 16AWg is 10 amps, # 14AWG wire is 15 amps, # 12AWG is 20 amps. As for stranded verses solid wire is mainly a matter of cost for me as solid wire is less by the foot then stranded but stranded wire is more flexible then solid wire, both have the same electrical rating in amps.

[BigAl 956]

My wire standards are to use 14 gauge stranded for your power bus lines and 18 gauge bi-color speaker wire to feed the track. These are very common wire sizes that can be found in multiple colors in the electrical dept. of the home improvement store.

Splice into your bus lines with the blue tap splice suitcase connectors. Avoid lockons and solder the feeder wires directly to the track. Protect each block with a 7 amp circuit breaker.

You should consider a ZW transformer for power. I also highly recommend building with O with O22 switches and not O27 track. Your layout will operate much better.

[rrswede]

Thank you for the responses, BigAl and Philly. Sorry my reply has taken so long. Have been out of town. I have decided to use 14 AWG stranded wire for the bus lines. I do have a fully operational ZW but the two grandsons who are the Rail Engineers each want to control their own track. At some point in time, I suppose the ZW will be used. I have read various posts regarding inline circuit breakers. What suggestions do you members have regarding brand name, part number and source of supply for the appropriate breaker?

Thanks, Swede

[BigAl 956]

7A breakers seem to be the right amperage to protect from a derailed train or other short.  I get this type from Digikey.com. They are not too expensive and I mount them to the panel of the layout with the optional locking washer.

http://www.digikey.com/product-detail/en/W28-XQ1A-7/PB188-ND/45068

Whatever breaker you settle on mount them in series with your block wiring. This is a must-do for any semipermanent layout.

Here is a link to my panel and how I secured the breakers.

http://www.modeltrainforum.com/gallery/files/6/8/4/9/100_3555.jpg

http://www.modeltrainforum.com/gallery/files/6/8/4/9/100_3554.jpg

[phillyreading]

I was looking at www.mouserelectronics.com and have found a couple of circuit breaker part numbers. 655-W57-XB7A4A10-8 an 8 amp breaker. 562-8LB07300DNN3BA 7 amp breaker.

[rrswede]

Thank you for your responses, BigAl and Philly. I have accessed the websites each of you have posted but have not made any purchase, yet. BigAl, could you please tell me what you base the suggestion of a 7 amp breaker on? Is it based on the fact that I plan to use 3 1033 transformers or what? I still plan to use 14 AWG stranded wire for each bus and 18 AWG stranded wire for track connections to two separate loops and 18 AWG stranded wire for accessory lighting and accessory operations on both loops. If I was to use the ZW, would you be suggesting 15 amp? As you can tell, I am still confused regarding the proper in-line circuit breaker to use. I certainly do appreciate the various responses.

Swede

[phillyreading]

The need for power is usually what you base your circuit breaker or fuse requirements on. How much power will your engine take and how many lighted cars will you have with that train? Most lighted passenger cars can take 1 amp each of power and most single engines take between 2.5 and 4 amps of power. An 8 amp breaker might do well for a three to four car lighted passenger train with two engines.

[phillyreading]

The post war ZW needs to have around 8 amp circuit breakers at each A to D terminal as the ZW only has one breaker for the whole transformer mounted on the common or return side. Also if using newer engines with modern electronics(1990 or newer engines)add a TVS unit rated at 32 volts AC bi-directional, and wire it across the hot and common on each output. Unless you really need it the only advantage of using 14 AWG wire with a 1033 transformer will be lower voltage drop, you could safely use 16 AWG wire with a 1033. I would use 14 AWG with a post war ZW just in case of a short.

[rrswede]

Thank you for the response, Phillyreading, or is Lee F. more appropriate? I do understand from previous postings that the 14 AWG is overkill for the 1033's that I will currently utilize but I'm pretty sure that my post war ZW will take their place in the future. Although Bob Nelson did not specifically state that I should use 5 amp breakers, he did indicate that the 1033's should trip around 5 amps. In his opinion, then, would his suggestion be that I use 5 amp breakers inline with the 1033's? BigAl suggested 7 amp breakers be used inline with the 1033's and you suggested 8 amp breakers for use with the ZW. Bussmann Type 1 auto reset 8 amp thermal breakers are available where I live but 5's and 7's are not. Am I looking for trouble if I use the Bussmann 8 amp breakers between the 1033's and the 14 AGW bus? Here is a link that shows the Bussmann I can get locally (  http://www.jbtoolsales.com/bussman-bpucb8-8-amp-type-i-universal-circuit-breaker/  ).

Swede

 

 

[lionelsoni]

Aside from compensating for a failed internal breaker, I can think of only two legitimate reasons for adding external circuit breakers:

o  To protect against faults between the non-common outputs (A, B, C, and D) of a multiple-output transformer like a ZW.  That doesn't apply to a single-output 1033 (unless perhaps you are using a fixed-voltage output, which might contact a variable output).

o  To allow safe use of smaller wire with a large transformer.  That only makes sense if your layout is small enough that there is no significant voltage drop to be avoided by using heavy-wire feeders.

You will find recommendations for using fast-acting circuit breakers and fuses, supposedly to protect delicate modern train electronics.  But, since those are vulnerable to overvoltage, not overcurrent, transient voltage suppressors are a better way to solve that problem.

By the way, fuses and circuit breakers are not very precise devices.  An ampere either way is no big deal.

[rrswede]

Thank you for the response, Bob. I do not plan to use a fixed voltage output on any of the three 1033 transformers, but the one feeding the accessories will be set to a fixed voltage. I also do not have any plans to operate modern train electronics even when switching to the ZW. At that time, based on your comments, it would be appropriate to add breakers to the non common outputs. Correct? What amperage, 15. or as low as 7?

Thanks, Swede

[David Barker]

A very  interesting topic.  Since all of my layouts since 1986 have used tubular track, both O27 or S,  I have used the old Marx breakers successfully.

[lionelsoni]

Since you're planning to use 14-AWG wire, anything between the maximum current that your trains draw and 15 amperes will do.  I would (and do, in my Z transformers) just use 15-ampere breakers.

[rrswede]

Thanks very much to all that responded. I'm all set until I switch to the ZW.

Swede