Hi all,
Mainly out of curiosity, today I purchased a basic digital clamp-around AC
ammeter ($60 Sperry DSA-400) to check the current draw on my Kay Phasemaster
and Felder machines.
The Phasmaster MA-1's original factory test results from two years ago show
it should draw at idle 4.6A at 242VAC. My measurements show about 4.2A at
245VAC. Although this meter doesn't have a peak hold function, start up
surge looked to be around 50A over several tests, but I don't know how
accurate it could be in measuring these very brief surges.
Since I only have only one twist-lock receptacle installed at the moment, I
can only test each machine running by itself. Here are those results as
measured on the single-phase supply to the phase converter:
AF-22 LN 3kW/3ph (3m of 120mm hose connected to saw, 3m of 80mm hose
connected to shaper, and a used but freshly cleaned pleated poly drum
filter):
Starting peak: ~50A
Full power: 7.0A (8A with 120mm hose removed)
BF6-31 2.2kW/3ph (table saw mode w/12" stock blade):
Braking self-test: 4.9A
Starting peak: ~40A
Idling: 4.5A
Remember - these results are with both the subject machine and the phase
converter running. I'm not sure if I should just subtract out the phase
converter idle current to get real values, or if it is more complex than
that.
When I get the second twist-lock recptacle installed, I'll check the 3-phase
voltage balance under load and 1-phase current draw with both the BF6-31 and
the AF-22 LN running simultaneously.
The single-phase amp measurements were taken on each of the two hot legs
inside my 30A quick disconnect to the phase converter. Curiously, there was
a consistent difference about about 0.2A between the two hot lines. I'm not
sure what would cause that, but maybe it has to do with the snap-clamp
transformer being proximity sensitive to the metal cabinet, or just the
results of not buying a more expensive meter. In any case, I took the two
measurements and calculated an average.
If I did this incorrectly, please somebody let me know. I'm also not sure
how I should measure the current draw on the 3-phase side. Do I measure one
leg, two legs, or all three and add/average the results? Not sure...
..Geoff
