How hot can a prewar motor get?

[Darth Santa Fe]

I just ran my prewar Lionel engine (with two passenger cars behind it) for about 10 minutes straight. After stopping it, the entire body had gotten warm, and the motor was pretty hot. So I was wondering, how hot can these motors run before they get damaged by the heat? How long can you prewar guys usually keep your trains running before they need a break?

[jeffrey-wimberly]

If it's getting that hot something is binding somewhere.

[Darth Santa Fe]

Everything turns very freely, and the cars roll fine.

[webenda]

Darth, -- Your description sounds normal to me. -- My longest train is 15 cars and has run for 45 minutes continuous. Engines get warm but I have never opened one to see how hot the motor is. I have run them open chassis with no load while oiling and lubricating them. The motors stay cold under no load condition. -- Exactly what temperature is "pretty hot?" You do not really need to know the numeric number to measure your motor's temperature. You can use your finger. -- First, a lesson in safe temperature for fingers. “Safe” contact skin temperature, for an exposure time of five seconds, is approximately 140 degrees Fahrenheit (60C). This is the upper limit, beyond which there is tissue damage that goes beyond the first degree burn, (i.e. the onset of second degree burning.) Use your finger thermometer with care or you will only get one use out of it. (Once burnt, it may never work again.) -- Motor surface temperature on can motors used in model trains can be high enough to be very uncomfortable to the touch. Mabuchi rates the operating temperature of their RS-550 at -22 degree Fahrenheit (-30C) to +176 degree Fahrenheit (+80C). -- Now for the touch temperature test. Tap the motor. Finger survive? If not motor too hot. If yes, try one second contact. Finger survive? If not... well you get the idea. Try two to five seconds. If you get to five seconds and are comfortable with the temperature, then the motor is running cool (relative to what is allowable.) I don't think any of my model train motors get too hot to touch, but like I said, I have never measured the temperature to be sure. -- I would expect the same sort of finger test to be applicable to pre-war motors. -- Any discussion on the touch test is welcome. -- P.S. Sorry for no paragraphs. CTT cannot handle paragraph commands from my computer.

[Seayakbill]

After extended periods of operation the shell of PW locomotives will be warm. If they are hot to the touch then some investigation is needed.

[gunrunnerjohn]

I've noticed some motors get warm to the touch, but I don't recall a properly working locomotive ever having a motor temperature hotter than I could grasp with burning myself.  The AC motors seem to get hotter than the DC can motors in most cases.

[Darth Santa Fe]

The motor gets hot enough that I can only touch it for a moment, and the rollers can get burning hot. The body was only warm though, so things may be pretty much normal from the sound of it. It does stay cool under no load. My other Marx and AF motors do the same. I may try a conductive lubricant for the rollers instead of 3-in-1 and see if that helps much, and look to see if there's anything else to make it work even more smoothly.

Thanks!

[gunrunnerjohn]

I think you have excessive current for some reason.  Do you have a clamp-on ammeter, I'd measure the current this locomotive is drawing.

 

[Darth Santa Fe]

I don't have an AC ammeter that I can clip on, but under DC power, it uses 1.5 amps under no load.

I picked up some ATF today and used it in all the bearings, and also put a small bit on the commutator. It's helped quite a bit! The whole engine runs more freely now and more easily pulls loads. I have all three of my 6-axle 710 series passenger cars rolling now, and it pulls them without any trouble at all. After similar run time, the rollers are still very hot, but the motor itself is running cooler than before. Problem solved, I think!

If I get any more trouble, I'll see if I can hook up an ammeter. But for now, all is well.

[jeffrey-wimberly]

Didn't I say something was binding somewhere?

[John Richardson]

Hi,

If the rollers are still hot, I would think there may still be an issue.  I recently purchased a 2055 that was doing the same thing, and after taking apart and lubing, etc. the rollers were still getting very warm.  Turned out the sheathing over the wire going to the smoke unit had degraded where it enters the small hole on the unit, causing excessive amperage draw.  Something to look at.

 

John

[gunrunnerjohn]

For the rollers getting hot, you might look into DeoxIT D5 http://store.caig.com/s.nl/sc.2/category.188/.f that will reduce the resistance of the contacts between the roller on it's axle.