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  1. #1
    Join Date
    Aug 2004
    Milan Michigan

    Default Crane for my shop addition

    I'm going to do an addition onto my existing welding shop, My shop now is 38' x 40' with a 16' ceiling, My addition is going to be 40' x 80' with 18' ceilings.

    My existing cranes are single phase on a hand pulled bridge, but the new cranes are going to have to span approximately 37'-6" which is to big to be pulling up and down the runway.

    Since its alot easier finding used 3 phase powered bridge cranes and next to impossible to find a single phase powered bridge I need to install a phase converter.

    Can I use a static phase converter for the crane ( Which I dont think I can ) or do I have to use a rotary.

    I know that pumps cant run on static phase converters and I would assume a crane would be the same.
    I currently have a static converter for the drill press which has worked great for the last 6 years.

  2. #2
    Join Date
    May 2011
    Bossier Parish La.


    Is this shop in a residential area or industrial? If not indutrial type area then the possibility of getting 3 phase power is about nil. Have you considered an engine drive 3 phase generator to power the crane? There are probably quite a few to choose from if you look around, just fire it up when you need to use the crane. Also Miller makes a 250 Bobcat that outputs 3 phase AC, might be just the thing. You would be staying true to your name "portable welder" with one, and still weld with it. Just a couple of thoughts on this situation.

  3. #3
    Join Date
    Dec 2007


    Another option is to convert the 3 phase motors to single phase.I did this with an Ironworker once. Had everything rewired and replaced the 7 hp 3 phase motor to a 10 hp single phase.
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  4. #4
    Join Date
    Sep 2005
    northern NJ


    I am not an expert but this is what I learned when looking for one.

    I was always told to only use rotory phase converters. I have one that powers my hyd. punch & a roller & it works good. If I remember correctly it really had to do with longevity of the converter & the power output. A static converter only produces about 1/2 to 2/3 of it's rating while running. So a 15 hp static will provide 15 hp for starting but only approx 7.5 to 10 hp when machine is up & running. A rotory will provide full hp for starting & running. Something about a static one actually disconnects itself once whatever your powering is up & running.
    Read about it here.
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  5. #5
    Join Date
    May 2009
    Central North Carolina


    If you can get 3 phase from the power company it's the way to go if there is a strong likelyhood that you will be adding additional 3 phase equipment, but it can be quite expensive to install. If this is to be your only 3 phase device, go with a rotary phase converter. You can use it for more than just the crane if you will only be running one machine at a time, but the phase converter will need to be sized to run the largest machine, so try to consider this and plan ahead when you buy it. You won't need it running full time, only when you need the 3 phase power, so have it wired so that you can easily turn it on and off.

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  6. #6
    Join Date
    Aug 2004
    Milan Michigan


    To the first response, Yes I'm out in the country so 3 phase is not an option.

    #2 My welder is 3 phase but thats even worse than having to hear a phase converter run, We use the cranes through out the day.

    #3 I did put a single phase motor on my iron worker and that works because the pump only runs in one direction.
    Because single phase motors only run in one direction while a 3 phase motor can easily be reversed by swithing your T-leads thats easy.

    Harrington Hoist company makes single phase trucks but they want 5,574.00 for them and I need 2 bridges that equal ___________________________ 11,148.00
    and that doesnt include the beam or the hoist or the runway.

  7. #7

    Default Static convertor

    I have a small shop at my house 30X60 I put a crane in it and used a static convertor the crane works fine but if there is a load on it when you stop it is a little hard on it to restart it. My crane is a 3 ton 5 hp 3 phase I have a small lath and the bridge crane and a milling machine all 3 phase I found me a 7 1/2 hp motor 3 phase and what I do is start the 7 1/2 motor with it not driveing anything with it running I can start up any of my other motors and they start up just fine I also have a 25hp motor on my big lathe the stuff I put in it weights over 2 ton I have a 30hp static convertor. it starts a little hard and it last about 1 1/2 seconds the power company had me put a pole with a meter for my shop but there was problem where they tied in to the power lines there was 2 other houses we were at the end of the line so when I started my lath they would see the dip in power in there houses and there were not to happy with they called the power company [lots of times] what ended up was the power company had to run a new line from the transformer to my meter to stop the dips and was great for me now my dips are less than a second. so this what I did and did not have to get a rotory they are a little priceeee I hope this helps

  8. #8
    Join Date
    Dec 2011
    maeystown, il


    I don't know where in the country you live but many farms have three phase so if there is one nearby they might have it so it wouldn't be a big deal to get it

  9. #9
    Join Date
    Aug 2004
    Milan Michigan


    I checked on 3 phase when I originally built my shop back in 2004 and its 2 miles away, If I remember they told me it would cost approximately $ 30,000.00 to bring it in.

    It looks like a rotary phase converter is going to be my cheapest way out.

  10. #10
    Join Date
    May 2008
    Troy, MI


    Quote Originally Posted by Portable Welder View Post
    My welder is 3 phase but thats even worse than having to hear a phase converter run.
    I know what you mean -- I have heard noisy rotary phase convertors. American Rotary makes a quiet one. You can have a conversation near it and hardly know that it is running.

    I also don't have three phase power on my street. I live about 1/4 mile from two main roads that both have three phase power. The estimate from the power company was $10K to supply 3 phase from one street and $15K for the other.


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