Trainmaster 4851 Transformer. Update 12/12/17 More questions...

This line says it all.

Type 4851              15VA

It's capable of less than an amp, so for anything more than lighting a couple of small buildings, I'd forget about it.

Good to know.  What would it have originally been intended to power?  A really small train?

15 VA is equal to about 50 watts, so it was packed with a 'premium' train set.

Uhh... Chuck 15VA is actually 15 watts.   Given a power factor of 1:0, watts = volts times amps.  In point of fact, since the power factor rarely is equal to 1:0, it's actually good for less than 15 watts.  Add to that the fact that those transformers were rated on input power, you can cut that by another 20%.

It was for a REALLY small train.

John, The 4851 transformer is the exact same as a 4150 transformer. The case on the 4150 states 50 watts, the case on the 4851 states 15 VA.  Lionel changed the markings when the toy train industry standardized on Volt amps instead of watts in the late 70's.

Chuck, in that case, it's clear that the transformer is labeled wrong.  There's no way you go from 15VA to 50 watts!

What’s The Difference Between Watts And Volt-Amperes?

I can't find it right now, but I think I have one of those or very similar. It's red, came with a 1982 'Thunder' something steam set with several cars. I distinctly remember seeing the 15va on it and wondering how it could have even run the set it came with?

I've been told the set was one of the higher end ones from 1982. Compared to today's trains it certainly is a big POS though, as is the transformer. We got it for our daughter for Christmas when she was 7. Seems like it was really expensive for back then too. She loved cars and trains back then. She still likes cars, both real and toy, but trains not so much.

Thanks for the additional info.  

As my trains are currently packed away, what setting should I use on my multimeter to test it out?  What readings should I be hoping for?

I'm thinking of using it on a mini-layout that I may use for wargaming.  It will be one engine and a maximum of 4 cars on a single loop with no elevation changes.  Is it likely to be enough power for that?

Finally got a chance to test it today. It works good. I only had it up halfway and it was sending my lighted conventional scout with tender and 6 cars zipping around the Christmas Tree loop.

Three more questions though.  

1-Something is rattling around inside, should I be worried.

2-The screws that hold it shut are an odd shape, almost like a hollowed out figure 8.  What kind of driver do I use for that?

3- Seems more powerful than it is labled, could it be labeled wrong?

If you want to open it up, you need to pry the handle off - this isn't always easy. The screws that I have seen on these are torx screws. I don't recall which size, but if you get any kind of bit set, it will almost be guaranteed to have the correct one.

Sounds like a Clutch bit.

A clutch bit it is!  I'll probably try various sizes of flat heads, but if I decide to order one are there different sizes of clutch bits?

Also, if I get those off will I still have to get the handle off before the bottom comes loose?  In that case I'd probably just let it rattle.  I really just want to get it open enough to let what I assume is a small piece of plastic tumble out, but maybe I should just not mess with what is currently working just fine. 

It's usually a piece of broken case plastic that's rattling around inside.

These transformers were assembled with several different screw types over the years, but the most common is the clutch drive screw.

The problem, though, is that the fastening operation on most was meant to be a one-way street -- I've yet to be able to remove those clutch drive screw conventionally even with the proper bit. If you're careful, you might be able to drill them out. Or maybe you'll be lucky and have one of the few versions assembled with a conventional clutch screw.

Lastly, if I remember right, you do NOT need to remove the handle on these to separate the case from the bottom.

TRW

Thanks.

I just got one to move just a tad and the case started cracking.  I think I'm going to repair the crack with some MEK and just leave it as-is.

A clutch bit it is!  I'll probably try various sizes of flat heads, but if I decide to order one are there different sizes of clutch bits?

Yes, there are.
I am not familiar with what your particular transformer uses.
All the Lionel transformers with clutch head screws that I have had on my bench could be disassembled with an Xcelite G-5324 fixed handle screw driver or a 99G-532 screw driver blade.
I am going to try to figure out the sizes (not marked).

99G-532 - 5/32 clutch head screwdriver blade - still made, around $5.00 but you would need a handle.

G-5324 - apparently no longer made. Two on EBay. One used for $10 with shipping. One new for $15 plus shipping.

And now I see how the size is coded into the item number.

gunrunnerjohn posted:

Chuck, in that case, it's clear that the transformer is labeled wrong.  There's no way you go from 15VA to 50 watts!

I've always thought that the 50VA RS-1 transformer was labeled wrong too. It has a 6 amp breaker, which is realistic, based on its weight and its far exceeding the performance of any 50 watt transformer.