The Stovebolt Site Forums The Shop Area The Electrical Bay Heater motor, is it 6 or 12v?

How can I determine if my heater motor is 6 or 12v? It's a Frankenheater of unknown history and all I know is that the motor has plastic insulated wires, not cloth.

I just need to know if I need to install a voltage reducer or not.

power it up and see how it runs on full 6V, if it seems slowish, try 12 [momentarily ], if it screams on 12, just get a 12V replacement instead of goofing with reducers

related: someone gave me some 24V fans [aircraft or marine] long ago and I checked them recently on 12V to decide their usefulness for daBus - perfect speed at half voltage, very quiet and they'll last longer

Bill

Thanks Bill, Problem is I don't have any 6v batteries car around. Would a 6v dry cell suffice?

Why do you dismiss the reducer?

dry cell might work if it's good enough, I use a battery charger that does 6 or 12 to power things, if you don't have one that does 6v, just try it on 12 .... adding another layer to go bad seems pointless to me, and there's 12V motors readily available to match the physical specs of the 6V one [size, speed, rotation direction, shaft], that won't cost much more than a reducer, maybe less even - the reducer is a heat generating device, just like the multispeed switch, why put another thing to burn out or start a fire under the dash?

Bill

When I rebuilt my heater a while back I had a heck of a time finding a 12v motor that matched the 6v in apperance.

I found a tip on DEVE'S web site .

He placed a new 12v motor in his 6v housing.

I did the same thing and was very satisfied with the results.

This will not answer the original question to this thread but may be an option for others

My heater has been in the box for about 5 years now. It was placed there by the PO. My question is.....it looks like the fresh air heater which is what's suppose to be in the box.
My panel is a 1052 so is the heater's the same?? I don't think so but I must ask!!

Amperage and voltage are inversley proportionate if you reduce the voltage to a blower motor you are increasing the amperage the blower motor is using. This will cause the blower to die sooner not last longer. As an example:
If your blower motor is rated at 24v and used 10amps to run, it would require 20amps to run at 12v and the windings in the blower may tolerate it for a while, but not for long.

odd that 24V solar fans seem to survive on speed controllers, and high tech freaks regularly use 24V fans on 12V for less noise from their 'puters - but maybe they change them often s'OK, I've got 3, definitely last my lifetime

Bill

DC motor speed is proportional to voltage. The current is proportional to output torque. Output torque is the same as that of the load.

On a blower assuming squirrel cage type power is proportional to the cube of speed change.
So
if I cut the voltage by half
I cut speed by half THEN
I cut power by 1/8
and current is way way down (probably a little higher than 1/8).

12V motor on six volt should run a lot longer -- most likely will fail due to bearings which is generally the case.

Yes you can test run it on a six volt dry cell. I use 9V to see if a motor will run - not for long battery gets HOT.
Dan Bentler

yes Dan, resistance is also a variable in Ohms law

Bill

For any given resistance (in this case the blower motor), the current is DIRECTLY proportional to the applied voltage, If you drop the voltage from 12V to 6V, the current will be cut in half. Ohms law never fails!

so perhaps i am operating on a AC principal? I am looking at a dual voltage AC motor and it speciffically states that 120v 40a - 240v 20a. we were alway taught it was inversley proprrtionate one goes down the other goes up? just too bad Im not smart enough at theory to back it up 8-)

if I=E/R, then assuming the same resistance of the DC fan, halving E reduces I [even if the resistance might be lower at lower speed, current still drops]

one difference in the AC motors is the different wiring to provide different resistance to provide the same rated hp at either voltage, as in P=I*E .... not all AC motors are dual voltage and a 240 motor fed with 120 wouldn't even start

Bill

VI; The principle applies to AC or DC. With the heater motor, the resistance doesn't change, so the current is going to be directly proportionate to the voltage.

With the the dual voltage electric motor, you can't just plug into either voltage without changing some wiring around, usually a jumper/strap with some numbered terminals (at least on the ones I've seen). So, using the formula that squeeze supplied above, we see that the resistance of the motor at 240V is 12 ohms, and the resistance at 120V is 3 ohms. hence the difference in current. The wattage of the motor however (Voltage times Current) is the same at either voltage.

Unless it gets cold for a long time in your part of NC I doubt you will use it much. I found that to be the case here in Dallas. These heaters don't work that well anyways.

I would hook it up and use it for as long as it works.

I would have agreed with the notion that "these heaters don't work that well anyways" until I drove home (in 2007) a ragged 1954 pickup that I had just bought. It had been shipped from WA state to NJ and I had to drive it about 180 miles to my home near Albany, NY (in December). The truck was supposedly drivable, but the brakes were dangerous and the steering was loose. The windows and doors rattled and it had no seals/weatherstrip/windlace. It was 8 degrees F outside and I had the foresight to bring multiple layers of clothes and a down jacket with hood.

To my enjoyment, the original recirculating heater was able to keep the cab so warm that I was able to drive comfortably in my shirtsleeves with no gloves.

The original Fresh Air (Air Flow style) heater in my 1954 Suburban more than adequately heats the truck, clears the windshield, and it had a variety of settings.

Alright So If I= E/R
lets say that E=12volts
lets say that the resistance of the motor is 24ohms
so R=24

using this data I=E/R or I=12/24 I=.05

Now if we change the voltage to 6v and the resistance stays the same then...

I=E/R or I=6/24 I=.25

So in theory the amperage did go up as the voltage went down.

I also checked my math HERE http://www.the12volt.com/ohm/page2.asp

Not to but into your conversation but 12/24=0.50.

watch that decimal!! .... 12 divided by 24 = zero point 5, not point zero 5 , you misread the calculator page

Bill

LOL see i told you i wasn't smart enough to have this conversation.

Woody, I watched your photoes on cab restoration. You have got to be older than me. I'm 60. You made things look so simple. You my friend (hope I can call you that) are a craftsman. No doubt about it. I would just like to kinda' hang around you and maybe some of your talent would rub off on me. May I ask how in the world did you learn to do all of that? I see so many of my problems in your photos. Mainly the doors. I have not been able to get the gaps anywhere near right. That's another story. I would love to see your truck when you finish. I know it's going to be great. Have a great day, and thank you. You should write a book. Steven "[email protected]."

Steven, you have a PM.

dang you guys are really getting deep into it here.

Hey Dollar, if you havent you should see some of Woody's work. I like your truck also. Not bad! Also like the saying at the bottom of your page. Love it or leave it. From a Vietnam Vet.

Hello Mr. Woody, thanks for the PM. I sure do hope to see your truck when you finish it. Take care. Steven