[Boatanchors] No-load current of dynamotors?
Charles
charlesmorris800 at centurytel.net
Fri Mar 11 21:20:26 EST 2022
Just wondering if anyone has measurements on the no-load input current
of their dynamotors (of various sizes).
My Bendix 2 KVA aircraft inverter is rated at 115 amp full-load draw,
per the nameplate. Now that I have a monster unregulated 24-28 volt
supply, I have measured the idling current at 26V at 40 amps. 1/3 of the
full-load current seems kind of high? I was expecting more like 10-20%.
The only 120 volt resistive load I had on hand was a 525 watt heat gun
element, and the output voltage dropped only a few tenths of a volt,
while the input current rose to 75 amps. Next data point will be a 900
watt electric heater (the inverter is rated for 1 KVA single-phase),
unless I rig up a three-phase load.
(The only other dynamotors I have are small ones for "ARC-5" receivers
and I haven't checked them yet).
It does have two carbon-pile regulators, the original selenium
rectifiers, and a couple of relays that draw a little here and there,
but nothing's getting significantly warm except the air coming out of
the rotating assembly (it has fans on each end cap that draw in, and
exhausts from the middle). I can only assume that this is normal
behavior? Thoughts?
Cross-posted to Boatanchors and ARC-5 lists.
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