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Fluke 179 keeps blowing fues

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AVGresponding:
Also bear in mind it can be problematic to get reliably accurate low-ohms measurements without a 4-wire setup.

I prefer to use a shunt for measuring car battery drain currents; I have a home-made one that is good for 70 amps or so, and anything above that it's just easier to use a clamp.

Fungus:
A clamp is the answer and you can get a plenty-good-enough one for the price of two or three of those fancy Fluke fuses.

eg. The Uni-T.

Paul LGF:
Clamps not to good when looking for a parasitic draw on the car battery, as most cars draw under 50ma.  You have to be so careful not to touch the clamp and change its position while checking, and make sure there is no magnetic influence near by.

J-R:
In many cases you can use the mV range on the DMM and probe across the fuse.

AVGresponding:

--- Quote from: J-R on May 22, 2024, 07:10:31 pm ---In many cases you can use the mV range on the DMM and probe across the fuse.

--- End quote ---

You can, but you need an accurate measure of the resistance across the fuse and a bloody good microvolt meter or you're not getting an accurate picture of the current flow.

For context, a 100A main battery fuse will have a resistance of something like 1mΩ, and 50mA through that is gonna be a volts drop of only 50uV, well down in the noise for your average handheld.
My home-made shunt is 10mΩ, giving me a better chance of seeing the signal over the noise at lower currents.

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