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Re: Massive Confusion.
In a message dated 11/18/98 11:20:17 PM Pacific Standard Time,
tesla-at-pupman-dot-com writes:
<< Someone that is using a welder as a ballast, I would like to talk to you
about your current measurements. Something is very confusing about my
setup.
I am using a lincon 225A welder as ballast for my pig. I shorted the output
of the pig, and took current readings with a borrowed current probe.
I got the following readings :
Welder | AC Current
40A | 20A
60A | 28A
75A | 33.7A
90A | 40A
105A | 47.4A
120A | 52.3A
At this point, I got worried, as I only have a 5KVA pig, and this represents
almost 12KVA input power, if you belive the readings. What bothers me, is
this
is 50% of the setting.. and the welder wants a 50amp breaker. Mind you, my
30A fuses were fat-dumb-happy at this setting.
So I cranked it up to 225A setting. At this point, I showed 90A on my meter
and finally my 30A fuse popped. (note that for this, I bypassed the pig)
This makes *no* sense to me. [though the readings are consistant with
what I measured via a resistor in line] its almost like the readings are
100% of the true readings.
This leads to 2 questions:
1) will someone that uses a Lincon welder and can measure the current please
check their values at the above settings.
2) Just how far can I push a 5KVA pig without it going *POOF*.
I admit I am a little disappointed.. I was hoping to be able to start at
about
2KVA, but if these numbers are correct, the minimum I have is 4.8KVA :/
Michael Baumann >>
Michael,
I used a welder as ballast for about a year and a half for my 5 kva pole
transformer. With a few ohms of resistance in series with the welder, I did
not have any problems throttling the current down to about 10 amps. The
welder was a Miller Thunderbolt rated at 40 to 230 amps ac. I have since
switched to a variac for ballast as the pole transformer was causing some 60
hz resonance with the tank circuit and blowing up my caps.
At 5kva, the transformer would draw approximately 21 amps. I have had my
primary current up as high at 40 amps (close to 10 kva) and typically run at
30 to 35 amps and the transformer does not even get warm.
Ed Sonderman