Technical intake heater "heat flange" how many ohms

[corcai]

Anyone know how many ohms the heat flange is supposed to be?

Mine seems to have a higher resistance than I would expect.

Can't find the spec in the manual or manufacturers site.

If anyone has a ducato with the heat flange instead of the flame starter could you please measure the resistance.

 

[andytw]

Don't know anything about these but googling would suggest it warms input air before it gets to the engine. You say it has a different resistance than you would have expected. What did you expect ?

If it is 12 ohms then it will pass 1 amp and produce 12 watts of heat which doesn't sound much.

If it is 6 ohms then it will pass 2 amps and produce 24 watts

If it is 3 ohms then it will pass 4 amps and produce 48 watts

Without knowing, I would suggest it would be well below 12 ohms and probably in the 2 to 3 ohm region or even less.

It looks quite stout and made to get hot.

andytw

 

[corcai]

Without knowing, I would suggest it would be well below 12 ohms and probably in the 2 to 3 ohm region or even less.

Generally they are
~ 0.5kw - 4kw
~ 40A - 160A
~ 0.3 to 0.075ohm.

I am measuring about 0.9ohm which seems way too high but there is some kind of thermostat in the center so I am wondering if that is supposed to brings in the lower resistance when it heats up.

I am of course assuming it doesn't have a negative thermal coefficient which it may. Unfortunately my clamp meter has died. I suppose I can drive the relay directly and measure the voltage across it when hot.

 

[Anthony489]

Looking at the sturdy construction, and thinking about the amount of heat needed (e.g. small hand held hair-dryer) I would suggest the power could be as much as 500 watts. This implies a current drain of 42 Amps at 12 Volts, and a resistance of about 0.3 ohms.

If this unit is fed from a fused circuit, the fuse will probably be rated at somewhere around 150% to 200% of the expected current drain.