The book by Neil Besougloff, Command Control for Toy Trains says.................

[Buckeye Riveter]

The Book by Neil Besougloff, Command Control for Toy Trains published by Classic Toy Trains Magazine in 2003, says at the top of page 28 the following:

The TPC 300 can output 300 watts of power to the rails in a single block; the TPC 400 can output 400 watts. Either is plenty for a single electrical block, and using the full capacity of the TPC 400 in a single block should be left to those with expertise in electricity.

That's a new one to me. Maybe Neil would like to explain this a little more here on the forum or maybe one of our expert electrical people, Bob and Roy have an idea what Neil is trying to say.

Then on page 20 of the same book it says:

The TPC 300 and TPC 400 are capable of handling 300 and 400 watts, far more than a PowerMaster, but with out Underwriters Laboratory approval.

Holy Toledo Batman, from these two comments are these things safe for us mere mortals to use?! [:0][:0][:0]

[tmcc man]

Buckeye, I know a little about electrical, but not that much. I have a TPC400, but I am only using one 180 watt powersupply. I know more about home theater systems, and more of that type of electrical stuff. I can not tell you about the inside of a TPC, the TMCC engines, or any of that stuff, besides knowing where the boards are.

[willpick]

I'll try to give you an answer, Buckeye[:)]. When dealing with high power devices such as the TPC's, there are some considerations that have to be observed. One is the size/length of the wire used to connect to the track from the TPC. Two, the connections at the TPC & the track. This is important as you need to minimize the resistance losses--- At 18V, a 300W TPC would be capable of handling 16.6 Amps! The 400W TPC would be handling a max of over 21 amps! At these currents, It's almost like wiring your house--- An example: if you have a 0.1 ohm resistance at the TPC output and your wire, at 10 amps you would be dropping 1 volt across that connection. It will tend to get warm after a while. Also, the TPC should be mounted where there is airflow, as it will get warm-- And as the UL limit for "toy train" equipment is 10 amps, that's why the TPC's are NOT UL approved[;)].

[Anonymous]

Neil is talking about "super power":

With a TPC 300 you can supply a single power district 270 watts of power[15 amps] when linked to two paralleled 135 watt PowerHouse transformers["bricks"].

With a TPC 400 you can link and parallel a pair of 180 watt PowerHouses for a 360 watt[20 amps] power supply or---you can parallel three 135 watt PowerHouses to achieve 400 watts of power[22 amps].

Among other things IC Controls designed the TPCs for paralleling, but be aware that you are producing power that is in "welding territory".

I routinely operate one of my power districts with paralleled 135 watt PoHos[270 watts] needed to consistently operate 11 lighted cars behind a "J" and 11 lighted cars behind a Ps-4 Crescent Ltd.

I have a pair of 180s paralleled also but rarely have the need to cut in more than one transformer. I protect all of my TPCs/PoHos with fast-acting fuses because the Potter-Brumfield type breakers are rated 2-15 seconds trip time. Even with a low wattage transformer you can get a lot of arcing waiting on cheap thermal circuit breakers.

[Anonymous]

About the only need for a TPC 400 is to power up a scale passenger consist like the Super Chief or 20th Century limited. You would probably have multi motored locomotives and a string of 13-15 scale illluminated passenger cars. This type of consist could easily exceed the 10 amps available on most "large" toy train transformers. About the only time I have actually seen this type of consist are at clubs or large modular displays.

As noted by previous posters you need to use heavy gauge wiring and quick acting breakers. 20 amps at 18 volts can produce nasty burns and melt diecast metal.

[Anonymous]

Chuck
The 22 lighted cars on the two trains I noted above in the same power district behind a "J" and Ps-4 typically show a panel meter load of 12 +amps at moderate speeds.
Apparently the best fix to reduce load would be replacement of incandescent bulbs with LEDs in the lighted cars.
I routinely use #12 gauge wire on all of my transformer/TPC outputs and extend it out to all layout "hub "terminal strips for further distribution[16 gauge short "spokes"] to rails.

p.s:
Some years ago you probably saw the IC Controls demonstration video narrated by Rich Melvin in which Lou Kovach demonstrated running 12 lashed up diesels powered by paralleled 135 watt PoHos linked to a TPC300.

[Anonymous]

I would probably replace the incandescent bulbs with some other form of low current lighting, either stream lighting packs or LED's. Not everyone is as "enlightened". I use TPC-300's but only power them with single 180 or 135 watt supplies.

chuck

[wrmcclellan]

Buckeye,

The advantage one can get by using a TPC 300 or 400 to power a block (or track) using a more reasonable 10 amps is that the unit will run cooler vs being maxed out with maximum current capacity. One needs to take into account wire sizing and connections with 10- 20 amp loaded circuits. As related above, poor connections and design can result in extremely overheated wiring or connections. Overheating can occur to the point of melting wire or worse.

I recommend you stick with no more than 10 ampere circuits per block (or track) and TPC 300/400. Make sure the TPCs are in an area that allows adequate air flow.

Since you are building this layout in the museum, I also recommend you install some of this power control hardware in NEMA rated cabinets or on metal shelving/cabinets. One should avoid placing these parts on wooden support structures for this type of application (public). You may have to make some enclosure considerations for the TMCC signal to these units (via the common terminal).

You may also need to paint the underside of your layout and all exposed wood with flame retardent paint depending upon local codes for displays. As all your layout voltages are below 40 volts, there are typically no electrical code issues for the low voltage wiring (but you should check).

As far as UL goes, the TPC units have been out long enough to establish a level of confidence in their design. It is quite difficult to find electronic components that are not rated for UL (which is basically a burn test). So even though the TPCs may not be UL rated, it is likely that every part (including the PCBs) are all UL rated. Thus I recommend you keep all your design loadings of layout electrical components (transformers and TPCs, etc.) to a 50% maximum load. This gives you a good safety factor and will increase the longevity of the components.

Regards,
Roy

[Anonymous]

TPC's can't be UL classified as a "Toy" train transfomer as their output exceedes the UL requirements for a toy transformer. The PH 180's were originally supposed to be PH-190's and were knocked back down to 180 watts in part to meet the standard and be elligible for UL approval.