Page 3 of 10 FirstFirst 123456 ... LastLast
Results 21 to 30 of 92
  1. #21
    Elite Member
    Join Date
    May 2012
    Posts
    2,972
    Location
    Knoxville, TN
    Tractor
    Bobcat CT225

    Default

    Quote Originally Posted by SPYDERLK
    True, but 240V gens dont work that way. Full rated power is only available from the 240. 6500/240 = 27.5 is the amps available. Only half power will be available from each 120V leg of the spit since the gen will be fused to protect its windings from current over 27.5A. That compressor will never start on the 120V output of that 240V gen.
    larry
    Bingo. Saved me some typing.

  2. #22
    Gold Member Boeing's Avatar
    Join Date
    Sep 2010
    Posts
    449
    Location
    Botetourt, Va
    Tractor
    kubota L3010

    Default Re: Generator won't power compressor....ideas?

    Can you help with the wiring of the 240 plug? The recep on the gen is a 4 prong with an L shaped for one of the prongs. My radial saw (don't know about the compressor motor yet) has fittings for THREE wires to go to 240V I did that years ago and used a THREE prong dryer plug. It ran GREAT...very fast and powerful. Anyway, if there are 3 fittings and 4 prongs for the generator......duh?

    ANOTHER question that I've had for years......this compressor pressure switch cuts the compressor off at 120PSI but doesn't RE-start it until about 85 PSI. When I sand-blast, for example, I need at least 100 PSI or I'm wasting time and sand. IS there a way to make this compressor come on at 100 PSI?

    The collective amount of knowledge in this group is AMAZING......I guess 10,000 guys averaging 45 years of acquired experience....WOW.


  3. #23
    Veteran Member chim's Avatar
    Join Date
    Apr 2002
    Posts
    1,837
    Location
    Lancaster County, PA
    Tractor
    Kubota L3200, Ford 1210

    Default Re: Generator won't power compressor....ideas?

    Quote Originally Posted by Soundguy View Post
    take his 4hp peak #.. convert to watts.. then convert to rms, assuming that number is a peak watt rating.. now use the hp conversion and go back to hp... the numbers bang out almost perfectly.

    so yes is does matter.. completely.

    you just have to understand electronics and economics...
    I do sorta understand electronics and economics. That's why I said the 4HP is a sales pitch calc. 4HP at a perfect power factor is approx 2.983KW. The full load curent the OP listed is 16A @ 115V at a perfect power factor is 1.84KW. There's no free lunch. The equivalent of 4HP cannot be produced at 115V and 16A. Buy yourself a good reference book and a Fluke and check it out.

  4. #24
    Veteran Member
    Join Date
    Dec 2010
    Posts
    1,033
    Tractor
    Massey

    Default Re: Generator won't power compressor....ideas?

    Real 4hp motors won't be available as 115v single phase versions. It makes no sense. My 5000/6250 generator tries to start my 230v 4hp compressor, but the elec motor stops when it tries to swich to run mode. It barely starts my 1hp 230v deep well pump. For the 1st full second the current maxes and holds at 30 amps, but at that point the gen voltage is down to 180 volts, and about 57hz. Then the pump comes up to speed and the current drops down to 9 amps. Of course deep well pumps have the added math of the long copper run. I beleive the B.S. "peak" hp ratings on shop vacs etc.. are calculated from locked rotor amps * voltage, which is very very misleading.Always go by the running amps * V.
    I f you want to do one better look at the rpm at that amp rating. The lower below either 3600 or 1800 rpm's the more slip they have "allowed" for the rating and this increases the current draw. so the plot thickens...
    Last edited by DarkBlack; 08-18-2012 at 10:47 AM.

  5. #25
    Super Member
    Join Date
    Feb 2008
    Posts
    9,392
    Location
    somewhere usa
    Tractor
    Deere 110tlb, 4520, x749, L130

    Default Re: Generator won't power compressor....ideas?

    I suspect your electric driven compressor will always be hard to run on your genset. If you need a good portable compressor and portable power at the same time I would buy an engine driven compressor for those uses. I say this because the little pancake compressors have a nasty habit of auto starting at the same time you are using another large tool. I bought an Ingersoll-Rand T30 with a 30 gallon tank (or close to that) two stage 175 psi about 19cfm back in 1998 to run my portable air tools, been a good unit and satisfied with it. Unless your sandblasting is some type of miniature rig it seems your compressor would be too small.

    Lots of bogus ratings on these little compressors and shop vacs, I remember a sales person trying to steer me to a 6hp peak shop vac with an 18/2 power cord 120v a few years back. That kind of misleading crap really turns me off. Most all 120v plug in appliances and tools are limited to 15 amps maximum draw that are sold in the US.

  6. #26
    Elite Member dex3361's Avatar
    Join Date
    Aug 2008
    Posts
    3,568
    Location
    N. of Charleston WV
    Tractor
    Kubota L4400-1 HST,FEL, 3x3 remotes, TNT. BX1500 54 mmm

    Default Re: Generator won't power compressor....ideas?

    Quote Originally Posted by Boeing View Post
    Can you help with the wiring of the 240 plug? The recep on the gen is a 4 prong with an L shaped for one of the prongs. My radial saw (don't know about the compressor motor yet) has fittings for THREE wires to go to 240V I did that years ago and used a THREE prong dryer plug. It ran GREAT...very fast and powerful. Anyway, if there are 3 fittings and 4 prongs for the generator......duh?

    ANOTHER question that I've had for years......this compressor pressure switch cuts the compressor off at 120PSI but doesn't RE-start it until about 85 PSI. When I sand-blast, for example, I need at least 100 PSI or I'm wasting time and sand. IS there a way to make this compressor come on at 100 PSI?

    The collective amount of knowledge in this group is AMAZING......I guess 10,000 guys averaging 45 years of acquired experience....WOW.

    You could make a 3 prong by 4 prong adapter for your generator or cut the end of the 3 prong plug off and put a 4 prong twist lock on the cord.
    Randall



    1Timothy Chapter 2:
    3 For this is good and acceptable in the sight of God our Saviour;
    4 Who will have all men to be saved, and to come unto the knowledge of the truth.
    5 For there is one God, and one mediator between God and men, the man Christ Jesus.
    From: The HOLY BIBLE

  7. #27
    Epic Contributor Soundguy's Avatar
    Join Date
    Mar 2002
    Posts
    48,364
    Location
    Central florida
    Tractor
    ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC

    Default Re: Generator won't power compressor....ideas?

    Quote Originally Posted by chim View Post
    I do sorta understand electronics and economics. That's why I said the 4HP is a sales pitch calc. 4HP at a perfect power factor is approx 2.983KW. The full load curent the OP listed is 16A @ 115V at a perfect power factor is 1.84KW. There's no free lunch. The equivalent of 4HP cannot be produced at 115V and 16A. Buy yourself a good reference book and a Fluke and check it out.
    you are either not reading my posts or totally not understanding them at all.

    this is clearly a peak vs rms issue.

    and YES.. it is an advertising issue.. they are saying 4hp to lure people in.. it's not an rms measurement.. and not what the user will or even could see based on how it is setup.

    i've got plenty of lab and industrial grade meters and o-scopes.. and had the ticket for years...

  8. #28
    Epic Contributor Soundguy's Avatar
    Join Date
    Mar 2002
    Posts
    48,364
    Location
    Central florida
    Tractor
    ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC

    Default Re: Generator won't power compressor....ideas?

    Quote Originally Posted by Boeing View Post
    ANOTHER question that I've had for years......this compressor pressure switch cuts the compressor off at 120PSI but doesn't RE-start it until about 85 PSI. When I sand-blast, for example, I need at least 100 PSI or I'm wasting time and sand. IS there a way to make this compressor come on at 100 PSI?

    The collective amount of knowledge in this group is AMAZING......I guess 10,000 guys averaging 45 years of acquired experience....WOW.

    it's a pressure switch like a well pump usually. there may be adjustable cut in / out points.. or it may be a set difference between cut in and out and only one adjustment.

    if the later.. be carefull.. you can exceede the pressure rating.. so may not be able to set a high cut in.. by keeping cut out correct.

    if both are adjustable.. just set cut in as desired..

  9. #29
    Super Member
    Join Date
    Feb 2006
    Posts
    8,499
    Location
    VA
    Tractor
    JD2010, Kubota3450,2550, Mahindra 7520 w FEL w Skid Steer QC w/Tilt Tatch, & BH, BX1500

    Default Re: Generator won't power compressor....ideas?

    Quote Originally Posted by Boeing View Post
    Can you help with the wiring of the 240 plug? The recep on the gen is a 4 prong with an L shaped for one of the prongs. My radial saw (don't know about the compressor motor yet) has fittings for THREE wires to go to 240V I did that years ago and used a THREE prong dryer plug. It ran GREAT...very fast and powerful. Anyway, if there are 3 fittings and 4 prongs for the generator......duh?

    ANOTHER question that I've had for years......this compressor pressure switch cuts the compressor off at 120PSI but doesn't RE-start it until about 85 PSI. When I sand-blast, for example, I need at least 100 PSI or I'm wasting time and sand. IS there a way to make this compressor come on at 100 PSI?

    The collective amount of knowledge in this group is AMAZING......I guess 10,000 guys averaging 45 years of acquired experience....WOW.

    4 prong provides for a true non current carrying ground, as well as the 2 HOTs adding to 240, and the neutral that allows splitting it down to two 120V circuits. Neutral can be connected to G potential at the gen, but you should ground the gen well or you will have a small charge on the gen when drawing from the 120 legs unevenly. If you operate only 240 tools this will not be a problem.

    You can turn up the pressure switch on your compressor, but the top pressure will rise equally. The better pressure switches have a secondary adjustment that allows you to increase the OFF pressure span. If yours has this and is already adjusted to increase it to a 35psi span you will be able to decrease it to mabey as low as 30psi [which is the customary minimum].
    larry
    This side of 40
    JD2010, Kubota L3450/FEL w SK QC, L2550 w FEL
    Mahindra 7520 [Pinky] /FEL w Skid Steer QC/w Tilt Tatch & BH, BX1500 [Mighty Mouse]
    IH37 Baler, CCM165 Drum Mower, JD Rake
    JD 127 bushog, Flail, SK Tilt Tatch , KK tiller, Rhino rear blade, Post driver, post auger, chipper, pallet fork, Grapple/Loader Buddy, Homemade Splitter/DC Welder

  10. #30
    Super Member
    Join Date
    Feb 2006
    Posts
    8,499
    Location
    VA
    Tractor
    JD2010, Kubota3450,2550, Mahindra 7520 w FEL w Skid Steer QC w/Tilt Tatch, & BH, BX1500

    Default Re: Generator won't power compressor....ideas?

    /
    Quote Originally Posted by Soundguy View Post
    you are either not reading my posts or totally not understanding them at all.

    this is clearly a peak vs rms issue.

    and YES.. it is an advertising issue.. they are saying 4hp to lure people in.. it's not an rms measurement.. and not what the user will or even could see based on how it is setup.

    i've got plenty of lab and industrial grade meters and o-scopes.. and had the ticket for years...
    It may be peak vs RMS V x I computation, sure. But I think its more like the Torque x RPM max the motor is capable of before breaking to a stall. It will burn up in a few minutes at that level because it will be drawing over 2x rated current.
    larry
    This side of 40
    JD2010, Kubota L3450/FEL w SK QC, L2550 w FEL
    Mahindra 7520 [Pinky] /FEL w Skid Steer QC/w Tilt Tatch & BH, BX1500 [Mighty Mouse]
    IH37 Baler, CCM165 Drum Mower, JD Rake
    JD 127 bushog, Flail, SK Tilt Tatch , KK tiller, Rhino rear blade, Post driver, post auger, chipper, pallet fork, Grapple/Loader Buddy, Homemade Splitter/DC Welder

Page 3 of 10 FirstFirst 123456 ... LastLast

Similar Threads

  1. Muffler ideas to quiet generator?
    By RanchMan in forum Related Topics
    Replies: 21
    Last Post: 11-24-2011, 04:16 PM
  2. Air Compressor Hoses...ideas on set-up
    By 9973720wb19 in forum Projects
    Replies: 13
    Last Post: 07-02-2011, 08:16 AM
  3. Compressor- Ideas?
    By Patiofarmer in forum Mahindra Owning/Operating
    Replies: 5
    Last Post: 07-18-2010, 02:09 PM
  4. PORTABLE AIR COMPRESSOR AND GENERATOR?
    By escavader in forum Rural Living
    Replies: 25
    Last Post: 10-04-2006, 11:48 PM
  5. generator ideas
    By glennd in forum Projects
    Replies: 8
    Last Post: 07-09-2003, 08:08 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
© 2014 TractorByNet.com. TractorByNet is a registered trademark of IMC Digital Universe, Inc. Other trademarks on this page are the property of their respective owners.