Wattage of Lionel type 4851 starter set transformer?

[Birds]

I was wondering if anyone know the wattage and max amp output of the Lionel Type 4851 transformer that came with starter sets in the 1990s.

The only specs I can find on the unit are: 7-19 VAC and 15 VA, which I take to mean a range of 7-19 volts with an actual voltage rating of 15.

I am using one of these to provide direct power to my O-22 switches and am trying to get an idea of how many switches it can power.

Thanks,
Birds

[Anonymous]

Allegedly about 50 watts. Normally a switch doesn't pull power and this wouldn't be an issue but the bulbs in the 0-22 do pull power, about .2 watts each. If you use the standard lighted remote throw, toss in a couple of more lamps. You are now up to 1/2 watt per switch. The switch motor's only draw current when thrown but they will pull a significant amount at that point in time, say about 15 watts. You could try swapping out the incandescent bulbs with LED equivalents or use multiple phased low wattage trasformers if the number of switches you wanted to run excede the capacity ot the 4851.

Couple of more points.

A) Never try to run a transformer continuously at its maximum rated output. (unless you like reseting breakers/replacing fuses). Leave a 15-20% cushion. The device will run cooler and will be less likely to fail. It will also better be able to handle intermittent transient loads. If you are operating "on the edge" these incidents should and probably will trip the breaker.

B) Check to see if the fuse/breaker is rated on the transformer. Prewar stuff was rated for power consumed by the device on the 110 volt side, not what was available on the output side. e.g. Post War ZW's were rated at 275 watts but could only put out 180 watts on the track side. Modern units are rated for output. If the fuse says 2.5 amps, then you have an approximate maximum of 45 watts. If you apply the guideline from A, you could comfortably supply 36 watts without a strain.

chuck

[pbjwilson]

Birds,
I use two of those transformers to power lights and accessories on my layout. I actually hide one of them in a building. They have there limits. How many switches do you plan to hook-up to the transformer?

[Birds]

Thanks. The explaination makes sense. I need to be thinking through power options.

Planning on eight switches, but it's possible to end up at 16. I haven't begun to purchase accessories and have no idea the range of wattage they draw. Is there an average that people use for estimating power needs?

If operating accessories also pull up to 35 watts, then one could easily have a call for 140 watts or more at one time between accessories and switches.

Do people dedicate large transformers such as the Z-4000 or new ZW just to power switches and accessories?

Thanks,
Birds

[Anonymous]

Dedicating a Z-4000 or new generation ZW is kind of pricy for running accessories. Some of us that have older PW ZW's that are in good shape will use those to run accessories. You can tune up to 4 variable taps to specific voltage needs. I wouldn't necessarily run out and buy one for this purpose. Alternatives are several smaller "phased" transformers, each one running a portion of the whole. Some folks have turned to the outdoor garden "low voltage" lighting transformers for driving accessories/lights. Peter Riddle's "Wiring Your Lionel Layout Parts 1&2" are a good source of information covering this (and a lot of other PW style tips/tricks). These can often be found at the local public library.

chuck

[Birds]

Thanks Chuck.

I have Peter Riddle's books, and they have been invaluable as I put my layout together.

Birds

[Chris F]

chuck, if the transformer data indicates 15VA, wouldn't that be a nominal 15 Watts? Also, did you mean the O-22 bulb used 0.2 Watts, or 0.2 Amps? Lionel shows a 1445 bulb rated at 18V and 0.25 A, or about 4.5 Watts.

[Anonymous]

Yes, reading amps and then typing watts. The contoler lamps are 4.5 watts each and the switch stand light is about 3 amps. Total is about 12 watts per switch!

I'm not sure what the reading on the transformer were for and suggest trying to get the current rating for the breaker. Most of the Ebay post re this transformer advertise it as a 50 watter. I can't find a reference in any of my docs for this unit. I don't know of a Lionel Toy train transfomer that was less than 35 watts.

Thanks for pointing out the descrepency on the bulbs.

[ADCX Rob]

QUOTE: Originally posted by chuckn

Yes, reading amps and then typing watts. The contoler lamps are 4.5 watts each and the switch stand light is about 3 amps. Total is about 12 watts per switch!

I'm not sure what the reading on the transformer were for and suggest trying to get the current rating for the breaker. Most of the Ebay post re this transformer advertise it as a 50 watter. I can't find a reference in any of my docs for this unit. I don't know of a Lionel Toy train transfomer that was less than 35 watts.

Thanks for pointing out the descrepency on the bulbs.

Another descrepancy... only 2 bulbs are "on" at any given time on a 022 type switch, or 4 per pair. 3 bulbs for a 1121/1122/1122E O-27 pair - one in each switch, one in each "dual" controller.

On the transformer issue, the 15 VA 4851 should be the same output as the 15 VA 4651 I have handy/nearby. My red 4651 weighs 2 lbs. 2 oz. What the 15 VA really means is anyone's guess...:

I have a later 70's blue 4150(black plastic handle) stamped "7.5 VA", it looks & weighs the same(1 lb. 14 oz.) as my 50 watt 4150(metal handle) from 1970 / 1971. There is no way that "7.5 VA" is correct!

It looks like Lionel really didn't know how to rate its transformers when they made the switch to a "VA" rating. The 4690 "MW" rated at 50VA is a good example - if you've ever used one. It really does have about 3 times the power of the 15 VA 4651, and certainly runs circles around any 1033/1044/4090.

The very similar RS-1 transformer is also "rated" at 50VA, but the text in the manual continually refers to "50 watts total" divided between the two channels. This is a very powerful transformer too, for only "50 watts".

The transformer cores on the MW & RS-1 are about the size of a R/RW, maybe a little heavier.

Rob