Checking amp draw help
#1
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Hello,
I have a craftsman amp meter clamp on. The lowest setting is 200 amp a/c.
When I check my amp draw on my 600 motor with 9x6 prop 7 cell 3000mha 8.4 volt.
it reads .9 amps . This cant be right what am I doing wrong??? Is there a conversion from a/c amps to d/c amps????
Thanks
I have a craftsman amp meter clamp on. The lowest setting is 200 amp a/c.
When I check my amp draw on my 600 motor with 9x6 prop 7 cell 3000mha 8.4 volt.
it reads .9 amps . This cant be right what am I doing wrong??? Is there a conversion from a/c amps to d/c amps????
Thanks
#2
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I have the craftsman model 82062. It has a selection for both AC amps and DC amps, so you must have a different model. The only think I can think of that you might be doing wrong, is that you need to put the clamp around only 1 lead.
#3

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Clamp meters can't read a constant direct current, so they don't work on brushed motors at full throttle.
On brushless motors, and on brushed motors at partial throttle, the ESC is switching the electricity on and off many thousands of times per second. To a clamp-on ammeter, these pulses look like AC current, and it can measure them accurately. Pretty cool, huh?
You need to clamp the meter around 1 wire only, as loading said.
I picked up a 100 Amp clamp-on meter from Harbor Freight for $10 a while back. It's within a 1/2 Amp of my Astro Whattmeter up until the brushed motor I tested it on got to about 3/4 throttle. Then, it started tapering off, and wasn't reading any current at all at full throttle.
On brushless motors, and on brushed motors at partial throttle, the ESC is switching the electricity on and off many thousands of times per second. To a clamp-on ammeter, these pulses look like AC current, and it can measure them accurately. Pretty cool, huh?
You need to clamp the meter around 1 wire only, as loading said.
I picked up a 100 Amp clamp-on meter from Harbor Freight for $10 a while back. It's within a 1/2 Amp of my Astro Whattmeter up until the brushed motor I tested it on got to about 3/4 throttle. Then, it started tapering off, and wasn't reading any current at all at full throttle.