Heater motor wattage?

[tony g]

Does anyone know the wattage of the heater motor so I can spec a new type of resistor for it. im looking at Arcol units as we have them at work. The resistance of the stock unit is around 1.5 ohms and thats easy enough to find in a modern type but obviously no good if it cant take the current needed.

Cheers

Tony

[Edin Dundee]

I can easily measure the current going through the heater on all settings if you can wait until the weekend.

[tony g]

That would be great Bill if you can thanks for that

Tony

[Jon Tilson]

Err isn't it just ohms law?

I reckon it drops the volts by half on low speed so 6 volts across 1.5 ohms...

Gives a current draw of 4 amps, so needs a rating of 24 watts....

Jonners

[Edin Dundee]

Hi Tony,

The motor takes 2.5 amps on full speed and 2 amps on half speed. Alternator voltage was 14V. The schematics show the resistor wired in series with the motor in one position and not used in the other position. Dunno if the schematics are accurate, it's too cold to mess around any further.
2 amps, 1.5 ohms, I Squared R losses of the resistor will be 6W.
Here's a pic of the resistor, seems quite chunky for 6 watts.....but then again the design is 60 years old!
IMG_5434 by edindundee, on Flickr

[tony g]

Thats awesome Bill thank you very much.

Tony