Doomfinger

I have a large power inverter that i bought to power an electric heater in my z. It runs a small 750 watt heater with no problems but i have a larger blower style heater that i want to use with a removable heating element. The element is 1400 watts and while the inverter will push it, it maxes out the amp rating of my alternator. Heres what i want to do. I'm planning on taking the element apart and shortening the coils to get about a 900 watt heater out of it. My question is will this work? Will shortening the heating coil reduce the wattage requirement? I already have the inverter and a high amp alternator so the setup works i just want to tax my alternator a little less.

evandubya

Ask FricFrac, I bet he'll know!

BrettjOR

What do you mean by shortening the coils?

Doomfinger

the heating element consists of a long nichrome coil wound back and forth in a metal housing. as it sits its a 1400 watt element. I need to know if i open it up and shorten the coil if it will lower the overall wattage of the element

turbopuppy

Just do the math. You said it's a 1400 watt heater. Thats a power rating.
To get current, divide the power by the voltage. The current is between 11.6 and 12.72 depending on the output voltage of the inverter.

Solving for resistance, divide the voltage by the amperage. You get about 8.6 to 10.3 ohms depending on the inverter voltage.

Those elements are just resistive load. So shortening them is like reducing resistance.

Say you tested the resistance and decided to trim them until your resistance dropped to 5 ohms. Then 120/5 = 24 amps. That is HIGHER than the original current.

Dont do it.

Doomfinger

Ok how could I cut this elementdown to lets say half of what it is now? 700-800 watts would be plenty to hear the car and my inverter could more than handle that load. I just need it down around 80 amps so I don't overload my alternator.

rogerz

ever hear of ohm's law? you can only run 750 watts no matter what you do. cut the coil decrease the resistance increase the amps. probably burn the coil up anyway so doesn't make much difference. E=IR in case you misssed high school physics.

Doomfinger

thanks for the flame.. I'll use that to keep myself warm in the mornings instead. I'll get it worked out one way or the other, just thought I could get a little help here. if I understood ohms law or took physics in high school I wouldn't be asking for help but if it makes you feel good cutting someone down for not understanding something then be my guest. see how far it gets you in the real world