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FeF stackable inverter system
  • Vote Up0Vote Down
    MetzMetz
     
    October 2012
    Can anybody tell me what the brand of inverters they are using at FeF for their shop?  My electric service at the new shop is terrible.  I ran out of room at the first shop already and moved to a new location that I discovered wont give me enough power to run the plasma torch. 

    I have wrote several times but never gotten a answer yet. 
     
  • 9 Comments sorted by
  • I may have a similar problem at my shop. I only have 40 Amps of single phase 240V coming to the panel. It's fine for everything but the TIG welder. I used to have a problem with not having three phase, but cheap VFD's  and a rotary converter solved that problem. I have a steam generator in mind to solve the amperage problem.
    --
    Kirk Wallace
    http://www.wallacecompany.com/machine_shop/
    http://www.wallacecompany.com/E45/index.html
    California, USA
     
  • Vote Up0Vote Down
    MetzMetz
     
    October 2012
    I got a little inverter DC welder that runs great on even the low power available in my shop.  the lights don't even flicker like when my neighbor uses his old fashioned transformer AC stick welder. 

    I think I found the inverters in Marcins video.  They are on Amazon for 200 dollars each.  So 5 units will get me the same setup.  I am unsure that their setup actually works now however.   I know that someone fixed the system but never left documentation online. 

    I cant even get 30 amps on the plasma torch and run the air compressor at the same time without the torch shutting down for low voltage. 

    I saw last week that the wires coming from the transformer to the shop have the insulation melted off them now.  It is not my part of the building and I cant replace the wires because I cant afford the cash and it is not my wires to begin with.

    I do have permission to install solar and rain water collection.  Waiting on a check to start that.  my water service here is terrible, slow barely works to wash hands.  Cant get enough water to even wash off the muriatic acid off of my steel parts very good.
     
  • Is this the inverter you are talking about?
    http://opensourceecology.org/wiki/Power_supply

    Do you have a power source to feed the inverter?

    What torch are you using?

    What area are you located?
    --
    Kirk Wallace
    http://www.wallacecompany.com/machine_shop/
    http://www.wallacecompany.com/E45/index.html
    California, USA
     
  • Vote Up0Vote Down
    MetzMetz
     
    October 2012
    I have the local shore power but problem is the low voltage.  I can use it to charge the batteries and supplement with solar or vice versa. 

    We are in Metro Manila, Philippines.  (went Galt and escaped the US)

    I am using a Hypertherm powermax45 torch here and a torchmate CNC table.
     
  • Vote Up0Vote Down
    MetzMetz
     
    October 2012
    I have moved my regular updates to my facebook page here  https://www.facebook.com/groups/438399309531129/
     
  • From this link:
    http://www.hypertherm.com/en/Products/Handheld_cutting/Systems/powermax45.jsp#specs

    it looks like you need around 230 VAC and 30 Amps or more, which is similar to a dryer or oven circuit. An 8kW generator might be big enough. For the short term, my plan is to fit my 10kW generator head to the front of my 18HP garden tractor. I burns gasoline, but I don't use my welder very often.

    One thing that comes to mind. If the circuit coming to your shop was meant to be 220VAC or close to it at 30 Amps and it dips under a load, then it seems the feed wires are too small, too long or have a bad connection. If too small or with a bad connection, the voltage drop creates heat which is very much a fire hazard. If the circuit is too long the drop and heat is spread across the length of the wire so is less of a hazard. It might be good to figure out which situation you have. Either way it's a waste of energy to use your service this way.

    It may be that the welder is similar to most of the VFD's I've worded with in that the input is a set of diodes that turn the AC right to DC. If this is the case, one might be able to feed the welder with 230V DC from, let's say, a bank of 20 12V batteries. On the other hand, the welder might blow up, burn and void your warranty.

    Your facebook link requires a login and I don't have a Facebook account, or plan to. I'm not sure Galt would have one either? Any way, I'm looking forward to any progress you make with your venture.
    --
    Kirk Wallace
    http://www.wallacecompany.com/machine_shop/
    http://www.wallacecompany.com/E45/index.html
    California, USA
     
  • Vote Up0Vote Down
    MetzMetz
     
    October 2012
    The transformer is the problem it is a very old 60amp model. Not mine cant do anything about it, nor the wires from the meter to the sub meter. I have 6ga wire from the sub meter to my part of the building. It is 6 months wait, 1250 USD for the application fee for my own transformer and meter plus a huge deposit.

    I didn't know the Facebook is not public. Settings say it is. Used to be one could view a Facebook page without a account.

    I seen those harbor freight 10kw generators sold here. The generator repair guy tells me that it is best not to use it for anything over 6500 watts. It is actually pretty small size compared to the genuine 12kw gensets I priced. I can't risk blowing up a 2000 dollar plasma torch using a cheap genset. Already did that with my air compressor. Supposedly it was a 3500wat unit but would not even run a 1hp air compressor.
     
  • A large induction motor can be used as a generator. You need something to spin it up, then put a temporary charge on a winding to magnetically charge the rotor. The rotor charge should remain as the windings are loaded.

    There are a lot of options available depending on what fuel and hardware you can get cheap. I live in the woods and wood is fairly cheap, so I'm thinking steam might be a good mechanical energy source. I happened to find a 10kW genset from a local junk pile, but large motors or making a genset from scratch might be possible. It's just a matter of getting what you want from what you got. Not having to rely on or paying someone else for what you want is good too.

    Blowing out a motor with insufficient power is easy and it's good practice to have a motor protector installed. They are similar to a power relay but have a current sensor (actually heater) that will trip the relay open if a leg is drawing too much current. If a motor's input voltage is too low for the motor's load, the motor will draw a lot of current, heat up the stator windings and burn up. With a motor overload relay, the sensors also heat up and cut power before your motor gets too hot.

    I suspect your welder converts the AC input to DC, then uses silicon switches (SCR's, FET's or IGBT's) to create AC or DC output with a high frequency PWM signal to control output voltage or current. This is usually controlled with a microprocessor which will check the DC bus voltage before turning on the output. In other words, if your welder doesn't like the input power, it should give you a DC buss voltage alarm before any harm can be done. There are no On/Off switches on my VFD's and they give me this alarm as they shutdown when I cut the power.

    Another thing comes to mind. The power here goes out a few times a year, sometimes I use my 4kW gas generator to run the essentials like the gas heater fan and refrigerators. Most gensets run at 3600 RPM and are very noisy. If you need to run your genset every day, I would look for one that runs at 1800 RPM which can also be loud, but the lower frequency is much less annoying. Also look to see if there are any duty rating specs. Cheap gensets use a Watt rating based on short duty instead of continuous duty, so they can advertise a bigger Wattage number. So the 10kW example may only run at full load for only a few minutes, but be fine 6.5kW running all day. Cheap gensets also wear out pretty quickly and are not meant to be serviced, yopu can't even change brushes on some. If something breaks, you are expected to throw it away and buy a new one.

    You can also run more than one generator on the same circuit. They need to be synchronized before being swtiched onto the circuit. Getting the sync or wiring wrong can be _very_ bad. You can find experienced people at SmokStak:
    http://www.smokstak.com/forum/

    in the generator section.

    Sorry, if I covered stuff you already know.
    --
    Kirk Wallace
    http://www.wallacecompany.com/machine_shop/
    http://www.wallacecompany.com/E45/index.html
    California, USA
     
  • Vote Up0Vote Down
    MetzMetz
     
    October 2012
    Steam is a little impractical where I am at. Basically if this was Los angeles, I would be in Ontario part. I am in one of the most densest populated places in the world.

    The generators I am looking at are big industrial units. I serviced gensets in Tikrit, Iraq for a couple years. I know a little about them.

    I did my cost comparison and decided to go with the inverters. My total usage for a month is less than 300kwh. And that was cutting 612 meters of 6mm plate. My welder is not the issue to power. It is my plasma torch. The welder is quite happy running on the low quality power. It does not even make the lights flicker, unlike when the neighbor uses his transformer based AC welder or runs his 2hp pressure washer.

    My biggest concern when going with solar is theft of the panels. People here steal everything. I have a full time live in worker at the shop and 2 guard dogs. But that won't stop someone from going up on the roof.

    We also are working on getting rainwater collection going. The water service is very poor. It takes a hour t fill up a 55gallon barrel.
     

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