"Don Y" wrote in message ...
On 2/18/2016 9:45 AM, Snuffy "Hub Cap" McKinney wrote:
I'm looking at adding a resistor or bulb inside an Acorn stair lift motor
housing to keep the temperature about 40degF. The unit is in an unheated
area and temps get too low for the motor to turn normally. I considered an
electric blanket or pad but having an elderly person messing with something
on the stairs is not a good idea. Also, there's the issue of having a
separate part and cord to deal with.

Cheat this out and see what you think. I have done this when setting up
electronic devices in remote locations, installed in an insulated box with a
car battery & resistor. In this case a night light bulb might be another
choice.

[Light bulbs burn out]

Good point

I don't understand -- doesn't the motor travel as well? So, how does it
receive power? (or, are the 2x12V the EXISTING power source for the motor?)

Motor is part of the chair. Batteries power the motor. When chair is at full top or bottom, battery contacts mate with rail contacts to keep fully charged. Transformer pluggs into the only receptacle which is at the bottom and connects with both top and bottom rail contacts.

Likewise, are the contacts already present (to provide charging current
to the traveling battery pack)?

Yes

I.e., is the only addition you are making that of the "heating load"?

Correct. I want to keep the compartment around the motor above 40 deg F when the night temperature drops to 20-30 deg. If it goes below 20, no one will be using the chair.

And, you presumably want it on at all times (possible exception
being while the chair is travelling -- as the motor is generating
its own heat *and* this would just be an added load on the batteries!)

On all the time.

[Is there a switch that tells the motor to turn on? As such, can you
tie into that to cause the heater to turn OFF when motor is ON?]

There is a switch. Good point. I'll look into that. If the chair got stuck mid-way for some reason, the resistor could possibly let the batteries run down.

Is the motor frame (reasonably) accessible? E.g., could you wrap
some heating tape around it KNOWING that operating the tape at
24V -- instead of 120V -- will cut the heat output to something
more desirable (I have no idea what the nominal output "per foot"
of those tapes is likely to be)

Thanks. That might be better than a resistor -- will check it out.