14 Kwatt 120 V Temp Services Load: How to Power with 440 V Welders?
14 Kwatt 120 V Temp Services Load: How to Power with 440 V Welders?
(OP)
I've got a series of welding and machining work to do at various job sites in the combustion turbine exhaust trucks of power plants.
Confined space work => needs lots of venilation, plus grinding and hand tools, plus 2x 440 VAC welders and a 440 VAC plasma cutter. All the gear has to be hand-portable, and small enough to get through the 30 inch wide x 42 inches high access door. At least the ladder to the platform is short. 8<)
The attached spreadsheet shows what we used at the last jobsite, but the temporary gensets (light trailers) were simply not good enough to carry the loads when two men were grinding while the fans ran; or when an air filter started up at the same time the bench grinder was lit off.
These are "nameplate" 120 VAC loads from each tool, which I'd assume is "running" condition. Some hotel loads (fans, lights, air filters, air exhaust mover) are going to be constant, but the hand grinders wouldn't always be runnning. Based on experience, what should I plan to need for "worst case" amps for the 120 volt supply?
How can I supply 120 VAC in enough amps from the 440 volt supply? Or can I without a heavy transformer?
Can I hookup my company's 220 volt/120 volt GFI panels somehow to the 440 volt lines - or must I continue to the 220/240 VAC 30 amp twist plugs on the light trailers? (And when those overhead lights ever get turned on - the unit trips on overload. So we need to rent extra light trucks for lights on night shift.)
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Most power plants have 60 amp 3 phase 440 VAC plugs at different locations around the turbines. Previously, the plant gave us "one plug" tied to a double outlet wire hard-wired to the two welders. When the plasma cutter was needed, we would unplug the welders and plug in the plasma cutter. Takes a lot of time at each job site to move wires and re-wire up all the gear.
If I assume I'm going to run either both welders or the plasma cutter directly from a 440 line, can I feed (legally, morally, and properly) that 440 volts line to a group of 4x breakers: One breaker for each welder, one for the plasma cutter, and one to the 120 vac services?
Confined space work => needs lots of venilation, plus grinding and hand tools, plus 2x 440 VAC welders and a 440 VAC plasma cutter. All the gear has to be hand-portable, and small enough to get through the 30 inch wide x 42 inches high access door. At least the ladder to the platform is short. 8<)
The attached spreadsheet shows what we used at the last jobsite, but the temporary gensets (light trailers) were simply not good enough to carry the loads when two men were grinding while the fans ran; or when an air filter started up at the same time the bench grinder was lit off.
These are "nameplate" 120 VAC loads from each tool, which I'd assume is "running" condition. Some hotel loads (fans, lights, air filters, air exhaust mover) are going to be constant, but the hand grinders wouldn't always be runnning. Based on experience, what should I plan to need for "worst case" amps for the 120 volt supply?
How can I supply 120 VAC in enough amps from the 440 volt supply? Or can I without a heavy transformer?
Can I hookup my company's 220 volt/120 volt GFI panels somehow to the 440 volt lines - or must I continue to the 220/240 VAC 30 amp twist plugs on the light trailers? (And when those overhead lights ever get turned on - the unit trips on overload. So we need to rent extra light trucks for lights on night shift.)
----
Most power plants have 60 amp 3 phase 440 VAC plugs at different locations around the turbines. Previously, the plant gave us "one plug" tied to a double outlet wire hard-wired to the two welders. When the plasma cutter was needed, we would unplug the welders and plug in the plasma cutter. Takes a lot of time at each job site to move wires and re-wire up all the gear.
If I assume I'm going to run either both welders or the plasma cutter directly from a 440 line, can I feed (legally, morally, and properly) that 440 volts line to a group of 4x breakers: One breaker for each welder, one for the plasma cutter, and one to the 120 vac services?





RE: 14 Kwatt 120 V Temp Services Load: How to Power with 440 V Welders?
Rent a portable generator.
When I think of portable lighting sets I am surprised that you are able to source one at 14 KW. I see hundreds of them at 6 KW and several manufacturers top out at 12 KW.
You didn't give us any load information on the welders or cutter.
Rent a generator of around 28 or 30 KW.
Voltage: It may be possible to reconnect the welders and the cutter to operate on 240 Volts or 208 Volts.
OR
Have the generator set for 480 Volts and use a transformer (480:120/240 Volts) to feed your 120 Volt equipment.
OR
If you need the temporary lights, rent a generator AND a light truck. (We call them light towers, probably the same.)
When you size the generator, bigger is better. You want to be able to set up and then go to work and forget about the generator until the job is finished.
Don't depend on plant power. You don't know the capacity from plant to plant and some plants may not be co-operative. I have seen instances where it took hours and sometimes until the next day to get a breaker reset on a plant outlet.
Bill
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"Why not the best?"
Jimmy Carter
RE: 14 Kwatt 120 V Temp Services Load: How to Power with 440 V Welders?
The welders are rated at 44 amp at 220 volt, single phase. 35 amp 220 volt on 3 phase.
We used 440 3 phase at 18 amp, 10 Kwatt.