How big a welder can I run off a 5hp rotary converter?

I calculate about 20 amps. Is this correct?

Gunner

It's better to be a red person in a blue state
than a blue person in a red state. As a red
person, if your blue neighbors turn into a mob
at least you have a gun to protect yourself.
As a blue person, your only hope is to appease
the red mob with herbal tea and marinated tofu.

(Phil Garding)

Gunner wrote:
How big a welder can I run off a 5hp rotary converter?

I calculate about 20 amps. Is this correct?

Maybe.
What output voltage?

Gunner,
Twenty amps is a good assumption. The math says, about 24 amps, assuming
50% overall efficiency and a .75 power factor. All this is based on a very
well balanced, "nearly perfect" 5 HP RPC. Ordinarily, I would guess a
welder is not very sensitive to impurities in it's source voltage; so
voltage balance in an RPC should not be a critical factor. Just to be on
the safe side, if the welder has some sort of electronic regulation, make
sure you connect the regulation phase across the 240 volt main.

Bob (as Walenda said, "balance ain't everything) Swinney

"Gunner" wrote in message
...
How big a welder can I run off a 5hp rotary converter?

I calculate about 20 amps. Is this correct?

Gunner

It's better to be a red person in a blue state
than a blue person in a red state. As a red
person, if your blue neighbors turn into a mob
at least you have a gun to protect yourself.
As a blue person, your only hope is to appease
the red mob with herbal tea and marinated tofu.

(Phil Garding)

On 12 Feb 2005 12:58:50 GMT, Ian Stirling
wrote:

Gunner wrote:
How big a welder can I run off a 5hp rotary converter?

I calculate about 20 amps. Is this correct?

Maybe.
What output voltage?

25 volts lets say.

Gunner

It's better to be a red person in a blue state
than a blue person in a red state. As a red
person, if your blue neighbors turn into a mob
at least you have a gun to protect yourself.
As a blue person, your only hope is to appease
the red mob with herbal tea and marinated tofu.

(Phil Garding)

On Sat, 12 Feb 2005 08:36:14 -0600, "Robert Swinney"
wrote:

Gunner,
Twenty amps is a good assumption. The math says, about 24 amps, assuming
50% overall efficiency and a .75 power factor. All this is based on a very
well balanced, "nearly perfect" 5 HP RPC. Ordinarily, I would guess a
welder is not very sensitive to impurities in it's source voltage; so
voltage balance in an RPC should not be a critical factor. Just to be on
the safe side, if the welder has some sort of electronic regulation, make
sure you connect the regulation phase across the 240 volt main.

Bob (as Walenda said, "balance ain't everything) Swinney

Its a minty but late 80s Airco PulseArc 350 mig welder. IRRC its 350
amp capable and the data plate says 208/39 amps.

It also says Electronic CV, but I doubt if its an inverter based
machine. Brand new Tweco gun, new and full tank of 75/25 etc.

Its currently sitting in my trailer out front of the house, the result
of a rather complicated 3 cornered swap that also netted me a nearly
unused Lincoln Weld Pak 100, a fair amount of consumables for both,
and a large New blast cabinet and another 400lbs of blasting media,
mostly beads.

I suppose I can only tell for sure by simply plugging it in and trying
it.

Gunner


"Gunner" wrote in message
.. .
How big a welder can I run off a 5hp rotary converter?

I calculate about 20 amps. Is this correct?

Gunner

It's better to be a red person in a blue state
than a blue person in a red state. As a red
person, if your blue neighbors turn into a mob
at least you have a gun to protect yourself.
As a blue person, your only hope is to appease
the red mob with herbal tea and marinated tofu.

(Phil Garding)


It's better to be a red person in a blue state
than a blue person in a red state. As a red
person, if your blue neighbors turn into a mob
at least you have a gun to protect yourself.
As a blue person, your only hope is to appease
the red mob with herbal tea and marinated tofu.

(Phil Garding)

On Sat, 12 Feb 2005 08:36:14 -0600, "Robert Swinney"
wrote:

Gunner,
Twenty amps is a good assumption. The math says, about 24 amps, assuming
50% overall efficiency and a .75 power factor. All this is based on a very
well balanced, "nearly perfect" 5 HP RPC. Ordinarily, I would guess a
welder is not very sensitive to impurities in it's source voltage; so
voltage balance in an RPC should not be a critical factor. Just to be on
the safe side, if the welder has some sort of electronic regulation, make
sure you connect the regulation phase across the 240 volt main.

Bob (as Walenda said, "balance ain't everything) Swinney

Its a minty but late 80s Airco PulseArc 350 mig welder. IRRC its 350
amp capable and the data plate says 208/39 amps.

It also says Electronic CV, but I doubt if its an inverter based
machine. Brand new Tweco gun, new and full tank of 75/25 etc.

Its currently sitting in my trailer out front of the house, the result
of a rather complicated 3 cornered swap that also netted me a nearly
unused Lincoln Weld Pak 100, a fair amount of consumables for both,
and a large New blast cabinet and another 400lbs of blasting media,
mostly beads.

I suppose I can only tell for sure by simply plugging it in and trying
it.

Gunner


"Gunner" wrote in message
.. .
How big a welder can I run off a 5hp rotary converter?

I calculate about 20 amps. Is this correct?

Gunner

It's better to be a red person in a blue state
than a blue person in a red state. As a red
person, if your blue neighbors turn into a mob
at least you have a gun to protect yourself.
As a blue person, your only hope is to appease
the red mob with herbal tea and marinated tofu.

(Phil Garding)


It's better to be a red person in a blue state
than a blue person in a red state. As a red
person, if your blue neighbors turn into a mob
at least you have a gun to protect yourself.
As a blue person, your only hope is to appease
the red mob with herbal tea and marinated tofu.

(Phil Garding)

On Sat, 12 Feb 2005 17:40:44 GMT, Gunner
wrote:


Its currently sitting in my trailer out front of the house, the result
of a rather complicated 3 cornered swap that also netted me a nearly
unused Lincoln Weld Pak 100, a fair amount of consumables for both,
and a large New blast cabinet and another 400lbs of blasting media,
mostly beads.

I suppose I can only tell for sure by simply plugging it in and trying
it.

Gunner

Well...by the grace of (insert deity of your choice) it runs just fine
on the 5hp RPC. I burned a couple hundred feet of wire today with it.
According to the meters on the front of it..I was running .035 wire at
about 21 volts and peaking at about 100 amps, with good puddle and
penetration. I loaded up a spool of .045 dual shield and it ran
pretty well too, but Ive got some wire feed issues that will need to
be worked out with that size wire. The proper sized groove in the
feed roller would help.

I spent 5 minutes doing nothing but laying down 6" beads, side by side
on a piece of scrap plate non stop and nothing got hot, tripped or
over loaded, so I guess the duty cycle of all the components, both on
the RPC side and the welder side was not approached. Frankly I got
bored before anything untoward showed up.

I guess that if anyone gets a chance to pick up a 3ph MIG cheap
enough, perhaps it might be something to consider, rather than
automatically pass by, if you have only a 5hp RPC. And older 3ph migs
seem to be fairly available (3ph welders in general) as folks change
over to the newer and fancier inverter based machines. I think at
most, Ill have about $50 in this machine when the accounting is done,
and it does a very nice weld indeed.

Gunner

It's better to be a red person in a blue state
than a blue person in a red state. As a red
person, if your blue neighbors turn into a mob
at least you have a gun to protect yourself.
As a blue person, your only hope is to appease
the red mob with herbal tea and marinated tofu.

(Phil Garding)