Anyone use two 120 volt compressors?

[RockRanger]

I am in escrow on a new to me house that is lacking open slots in the panel to add circuits. I will not have the money to upgrade the panel right away for my needs so I am trying to figure out the best bandaid for the short term. I have a 4x8 Torchmate 3 table and a Hypertherm 1000 plasma cutter. The plasma cutter I can use the dryer circuit which is right next to the garage. I have a 110 volt 27 gallon oilless compressor that is roughly 5-6 cfm. I also have a 110volt oil 4 gallon that I use for running nail guns etc for work. It is around 4-5 cfm. I know I will have to get them plugged into different circuits around the house. I have enough 10 and 12 gauge extension cords to probably reach around the house twice if I need to. I have the same amount of 3/8" air hose. I am thinking of running one compressor in the garage next to the table then the second one wherever i can get on a separate circuit power at. Then run separate air hoses to close to the plasma cutter then into a T and then one short hose to the plasma cutter. Not sure how to get them to kick on and off at the same time though or if it will matter how close then come on and off with each other. I doubt a gas powered compressor will go over well in the neighborhood or with my wife.

[Marty]

I dont' know where to start to answer your problem.......you have available only so much power.....no more no less.............running extension cords is a very temporary solution applied to a permanent problem............and extension cords just INCREASE the amount of watts needed at the machine because the extension cords increase the resistance to power flow......unless you are looking for an early 4th if July, and some nasty smoke, PLEASE talk to a local electrician......it is no co incidence that the National Electric Code is found within the auspices of the NFPA (National Fire Protection Association ) ...why?.................because electrical overloads and shorts start 75% of structure fires.....sorry, but there is no magic to be done.......

[I Lean]

One possible option for you, is if you can replace some of your 120V breakers with the smaller double breakers--basically combine two of your existing circuits into one breaker spot. If you do that two times, that will free up two spots so you can put in a 240V breaker and run a new circuit for a "real" compressor.

[planetxfred]

I initially operated my HT 1000 and a 5hp compressor from a single circuit. Took a bit of planning, A bigger tank is essential. get the compressor up to pressure, do some cutting, when the compressor is ready to start up, stop cutting. A pain in the A$$ but doable. You will look forward to having a separate circuit for each.
Fred

[CNCCAJUN]

One possible option for you, is if you can replace some of your 120V breakers with the smaller double breakers--basically combine two of your existing circuits into one breaker spot. If you do that two times, that will free up two spots so you can put in a 240V breaker and run a new circuit for a "real" compressor.

This is the best solution & perfectly safe . . . . and legal . . .

[RockRanger]

The house already has the split breakers in the panel. It is track house typical save every penny the builder can. I have not seen the house yet. My wife picked it out and i get to pay for it. So far my best guesss on the best solution to meet my needs is to pull the dryer breaker out of the panel and use the space opened up to feed a subpanel in the garage and then feed the dryer out of this panel. That is down the road though. If i can run the two compressors i already have and somewhat work I will do it for a few months till i can get to doing all the rewiring.

[Marty]

The CORRECT WIRE SIZE is critical to a safe circuit....you must SIZE THE WIRE FOR AMPACITY AND distance.....if the wire is too small, the wire will fry and spark if there is a short or overload..........and each size breaker has a MAXIMUM wire size that can be used with it.......I cannot urge strong enough to at least consult with a licensed electrician and show him what you want to do...even if you do the work, please consult a preofessional to verify what you intyend to do.....also, read the fine print in your homeowners insurance policy about NO coverage because you cheaped out and installed incorrect items....

ALSO....has anyone told taken into account that you must NEVER put a load on a breaker that exceed 80% of the breaker amperage....this is code ...............

AND, conduits are rated for a maximum number of wires etc etc.....

AND....voltage drop across the distance the load is carried on the wires cannot exceed safe amounts.....the longere the wire, the more voltage drop, the more volatge drop, the more amps are pulled from the breaker.....

Ask your local fire department what starts most of the fires they repond to.......

Hey Rock Ranger....PM me and I will send you my phone number if you want to discuss...

Marty

[RockRanger]

Marty, I fully understand all of the electrical side of things. I have already spoke with with my electrical specialist on my current project about this. I still have not seen the house only a few cell phone pictures my wife took. I have been a licensed GC in CA the last 6 years and currently managed federal projects. I have built small things up to my current project that has a 1000 amp 208 3 phase power feeding 7 subpanels throughout the building. I was simply asking if anyone has used 2 compressors plugged into different circuits to power there plasma cutter with much success. I know I need them on separate circuits which is why one compressor will probably have to be on the other side of the house and run a long air hose from it. I plan to upgrade everything in the future (6-12 months) but would like to use my plasma table to make some cash to pay for the upgrades.

anyone want to come over to my pool for a beer.

[Marty]

Hi Rock Ranger

Wow did I mis interpret your first post...apologies....when you said enough extension cords do reach around the house twice I had a vision in my head that I just could not shake.....sorry....so if each of the two circuits is capable of feeding
each separate compressor with no overload.....and the combined cfm out put of both compressors is sufficient to meet the air demand of the plasma unit.....then tying together the air discharge to a common point ( maybe a tee, or a third common air tank) would be the temporary ticket....I agree..........

When I come to your pool for a beer, I may just sit outside on the deck and wave occasionally:) I saw your picture

Hey good luck when you get past this electric crap and can start to create cool stuff.......and enjoy your new home!

Here is a link for some pictures of code "how not to do" http://freepdfhosting.com/7cc146e721.pdf

(it takes a few seconds to load)



Marty

[abmagrum]

hi, rock ranger you probably can do small projects with this set up but it depends on how big youre compressors are.
you want all the pressure you can get . higher the pressure the better the cut.
this is what you do if you want to try it

you have to use 3/8 or bigger hose 3/8 not 1/4 connecters a must.

you tee the 2 compressors together you need a water filter

then you need to put a pressure gauge at the back of the plasma cutter that's the only way you know its going to work

you have to stay at least in the 80 psi range or higher any lower and you wont get good cuts you ideally want 90 or higher but as long as you don't go below 80 you should be good to go

you want to cut something small while its cutting you watch the gauge and it will tell you where you stand I cant say if it will work or not but if you already have them this will tell you were you stand.

hope this helps

[RockRanger]

I hate searching old threads and never finding if what was proposed works or not. The views here are coming from someone with little experience with using a plasma table.

I am using a "5Hp" 27 gallon Coleman 120v oiless that says it puts out 5.6 cfm @90 psi. Probably re badged as a bunch of other brands as well for homeowners. The second is an Alltrade 4 gallon oil bath that puts out 3.8 cfm @ 90 psi. This one is similar to what a lot of contractors runs nail guns off of on construction sites.

I first cut with just the Coleman running. When the tank was full it would cut okay but once the compressor kicked on you would eventually see a drop in quality of the cut as it was not producing enough air to keep up. When I added the Alltrade and got it running it seems the cut would stay better. I was doing short cuts 3-5 minutes. If I plan to use this more in the future I need to play with the times that the compressors kick on and off to get them more evenly matched.

Bottom line I think you could make it work with lots of trial and error but is no where near a long term solution. I am on the hunt for a larger compressor and upgrading my electrical so I have enough circuits. I need to get a quality air system resolved before I can work on dialing in all of my cuts. Here are somethings I cut using this system. I would not consider any of them high quality cuts. They worked for what they were intended for. Bracing and feet for the water table.