How Much Power is Too Much

[Wutt]

Hello,

I have an O Scale layout on a 6'x14' table. It has two loops that fit inside of a 6'x10' area and a rail yard in a 6'x4' area.

I am running the MTH DCS system. I have two MTH Z-750 transformers (75 watts each). One is connected to the "Fixed 1" input of the TIU and the other to "Fixed 2".

I typically have two trains running simultaneously. One is a freight train with an MTH locomotive pulling about 9 cars and the other is a MTH Amtrak Genesis locomotive pulling 6 lighted SuperLiner cars.

When I use the DCS system to measure the track voltage it is averaging about 24 volts. All trains run fine.

Here's my question...I have only had the Amtrak SuperLiner cars for a couple of months and probably haven't ran them more than 10 hours and the lights have burned out in 3 of the 6 cars already. Shouldn't the lights last longer than 10 hours? Is this a result of too much power?

Also, during the CHRISTmas season I had a Lionel Polar Express set with six lighted cars running. That set is a few years old. However, during the season the lights burned out on 5 of the cars. I ordered replacement bulbs but when I went to change them the bulb fixture in a few of the cars has melted into the socket. Therefore, I will need to replace the entire bulb/socket assembly. Again, is this the result of too much power?

I know that MTH makes a 400 watt transformer. If I blowing bulbs with two 75 watt transformers I can only imagine the damage this thing would do to my equipment.

I can't find anything on the web regarding a "rule of thumb" regarding how much power is needed for a layout. Is there somewhere I can go to get information and find out why I'm blowing bulbs prematurely?

Thank You in Advance,

[overall]

I beleive 24 volts is way too much voltage for those car bulbs to take. I wouldn't put more than 20. In fact, you should probably not have more than 15.That's your problem right there.

[Major]

Alot of light bulbs on toy trains are only rated for about 14 volts, they will not last long at 24 volts. On trains that I run on TMCC I have replaced the lower voltage bulbs for (if I remember correctly) 28 volt bulbs.  I only have max output of about 18 volts so these higher voltage bulbs will last longer than the 14 volt bulbs. I believe 24 volts is exessive for your needs.

[Wutt]

Thank you for the information. So, to get the voltage down should I take one of the Z-750's (75 watt) transformers off the layout leaving me with one 75 watt transformer? 

Thank You. 

[webenda]

Forget about Watts Wutt. Note the two responses above only talked about volts. The reason is the primary specification on light bulbs is volts. If your Polar Express set uses Lionel 600-8352-311 lamps with the plastic wedge base, it is a 12 volt, 70 mA bulb.

 

Service instructions for Madison cars advise: When ordering replacement bulbs from Lionel Customer Service, please note the correct part numbers are 612-3011-311 for 14 volt and 620-5100-300 for 18 volt.

 

Don't actually forget about Watts. If your six cars have 12 12 volt, 70 mA bulbs (0.84 watts each) they add 10 watts (at 12 volts) to the load on your transformer. You need to consider engine load plus bulb load in watts when selecting transformer wattage and lamp voltage rating when setting voltage out of the transformer.

[Wutt]

Thanks Wayne. Taking the lights out of the equation...are two 75 watt transformers too much for my layout? Are the bulbs a symptom of a bigger problem?

The Z-750 tranformers are "bricks" so there is no way to regulate them in any way...not amps, volts, or watts.

One of my concerns is eventually damaging the electronics of the DCS system in the TIU (brains) and the decoders in the locomotives.

Am I at risk of doing so?

 

Thank in Advance for your help.

[overall]

Power (watts)=Voltage (volts) x Current (amps). Just taking away one of the bricks is going to reduce the available amps of current. That will reduce the number of trains and accesories you can operate. The light bulbs you have are not designed to hold the voltage you are trying to operate them at. You have just got to reduce the voltage to your equipment. I have to confess that I am not familier with the MTH system. Maybe someone who is an MTH fan can wiegh in.

[webenda]

Wutt

Thanks Wayne. Taking the lights out of the equation...are two 75 watt transformers too much for my layout? Are the bulbs a symptom of a bigger problem?

The Z-750 tranformers are "bricks" so there is no way to regulate them in any way...not amps, volts, or watts.

One of my concerns is eventually damaging the electronics of the DCS system in the TIU (brains) and the decoders in the locomotives.

Am I at risk of doing so?

 

Thank in Advance for your help.

 

To add to what overall said, no problem using two Z-750 bricks. The DCS system decoders and TIU were designed to use the voltage supplied by the bricks. You could use 750 watt bricks (1,500 watts total) without a problem*. The voltage would remain the same.

The bulbs are not a symptom of a bigger problem. Here is what M.T.H. has to say about the bulb problem:

What is the effect of full voltage on the lights in M.T.H. switch stands and passenger cars?

 The bulbs used in the switches are rated at 18v. They can operate at slightly higher voltages, but continuous operation at higher voltages (20-25v) will reduce the average life of the bulb and generate a lot of heat.

 MTH took the precautions of ensuring that our passenger cars bulbs would work at high constant voltages some time ago. Most passenger car bulbs are rated at 18 volts and so will have full lives running at constant 18v loads or less; others are rated at 14 volts, so will have slightly shortened lives if running at constant voltages higher than that. All passenger cars bulbs made in the last few years have been protected against overheating in a high constant voltage environment.

 

Some of the words used by M.T.H. are not technically correct, but they do get across the idea that M.T.H. is aware of the light bulb problem. If you read between the lines, they are saying 18 volt bulbs are not rated for 24 volts, but they use them anyway.

Some users of Lionel passenger cars with 12 volt bulbs have changed the bulb wiring in their cars from parallel to series. Series wiring cuts the voltage to each bulb in half. Lionel once did this themselves. When 6 volt automobile bulbs were common, Lionel wired two 6 volt bulbs in series in their passenger cars. This allowed the use of 6 volt bulbs with 12 volt track voltage.

*M.T.H. instructions say not to use transformers with outputs in excess of 190 watts without inline fuse protection.

[Wutt]

Thanks again for the great information. OK, since I now know that my TIU is safe and if that's safe then I assume my DCS locomotives are safe too.

One last question...Is it possible to get 24V light bulbs for my SuperLiner cars and if so where?

 

Thanks again!

Mark  ><>

[webenda]

The MTH Superliners use six 18V Grain of Wheat bulbs. The bulbs slip into a plastic carrier then the bulb leads are bent around the carrier. The leads make contact with the light strip buss when the carrier is inserted. These 24 volt grain of wheat bulbs should work.

Source:=> http://www.ebay.com/itm/Grain-of-Wheat-bulbs-100-pcs-5mm-Clear-24V-Mini-Bulbs-/390180061896?_trksid=p2054897.l4275

 

 

You get 100 bulbs for $11.99. They are located in Guangzhou, China (just outside Hong Kong.) The dealer is (hold on to your chair, wouldn't want you to fall off) "wehonest_cn." Alright, funny name, but I have made several purchases from wehonest and all but one arrived ten days after I placed the order. One took 29 days.

 

 All shipments were delivered by the USPS to my mailbox. Those that took ten days must have been shipped air mail (the package didn't say) because container ships take 11 to 13 days to cross from Hong Kong to Los Angeles.

[riverrailfan]

Don't rely on the DCS remote to show you the voltage. Make a measurement with a DVOM at the track to be accurate. My remote the other day said my track voltage was 27 volts with a ZW. I know it is around 19-22 volts. If it was at 27 volts, all the bulbs would be burned out in my cars but over voltage is what is causing your issue. You might want to invest in a different transformer. I find it hard that a Z750 power pack outputting 24 volts because I use a Z500 to power my TIU input.