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Thread: Wide Belt High Amps on Start

  1. #1

    Wide Belt High Amps on Start

    I just took delivery of a Grizzly G0539 37Ē belt sander and just getting it set up. Super excited to get it dialed in... itís an impressive piece of equipment!

    The manual says full load is 40.6amps, and recommends a 50 amp breaker. It recommends running around 25 amps, but that is what I see under no load. Is that typical?

    Iím also seeing a huge spike at startup... 60-70 amps. Is that normal? I will call Grizzly in the morning but hoping anyone with experience may be able to comment on no load and starting amps.

    Thanks,
    Toby

  2. #2
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    Yes, thats normal. I assume your looking at an amp gauge on the machine? When you start the machine it requires a lot more energy to get up to speed, thats the spike. Once up to speed it requires much less to run and will have a normal operating range, on mine it's roughly 20%. I don't know about running amperage on yours. On my machine if Im sanding correctly theres little to no increase on the amp gauge when I feed parts through. If I push the machine it will move though, and if I do something careless it will really spike. Generally though you don't want to overwork the machine or the paper on it and so take multiple small passes vs one heavy pass.

    good luck,
    JeffD

  3. #3
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    Quote Originally Posted by Toby Jutras View Post
    I just took delivery of a Grizzly G0539 37Ē belt sander and just getting it set up. Super excited to get it dialed in... itís an impressive piece of equipment!

    The manual says full load is 40.6amps, and recommends a 50 amp breaker. It recommends running around 25 amps, but that is what I see under no load. Is that typical?

    Iím also seeing a huge spike at startup... 60-70 amps. Is that normal? I will call Grizzly in the morning but hoping anyone with experience may be able to comment on no load and starting amps.

    Thanks,
    Toby
    that is normal. the FLC on my sander is 39amps (probably same motor as yours), but the startup will be 5-6 times the FLC. because of this I installed a VFD to limit the startup current to FLC. some machine has star delta start which limits the start up current to 2-4 times but still a lot of demand.

    my board is only 63amp. 400v.

  4. #4
    Thanks guys. The starts were a bit unnerving flickering the lights. Iím running through a PhasePerfect on a 100 amp circuit so maybe that is contributing?

    The PhasePerfect folks sizes it based on this machine.

    Iíll still call Grizzly in the morning. Even if itís normal, Iíd like to soften the start just to reduce the pucker factor.

    Toby

  5. #5
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    My 2 hp dust collector amps at startup: https://www.youtube.com/watch?v=XGIeq_kDGaI
    NOW you tell me...

  6. #6
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    A 20 hp PP on a 100 amp circuit should handle the machine. I'm surprised a 15 hp machine doesn't have a soft start built in. Dave

  7. #7
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    I donít think that is normal? It definitely should not be dimming your lights. I run a 25Ē SAC 10hp using a 10HP PP. Check your pneumatic pressure on your belt tracking/tension. Maybe back off the pressure a bit? That made a difference on my machineís start up. Also, I always start the feed belt motor first followed by the wide belt motor.
    Hope that helps.

  8. #8
    Its call break away torque.
    It typically takes 7 times the FULL LOAD AMPS to go from a dead stop to rated RPM.
    If you had a recording amp meter you wold see it.
    But in the end it is normal operation.

  9. #9
    Quote Originally Posted by David Kumm View Post
    A 20 hp PP on a 100 amp circuit should handle the machine. I'm surprised a 15 hp machine doesn't have a soft start built in. Dave
    Glad to hear your thoughts because thatís exactly what I have. The whole shop is on a 100 amp feed from the house, so that may explain the lights dimming on startup.

    Once started, the compressor and dust collector donít seem to have any adverse impact.

    Thanks,
    Toby

  10. #10
    Quote Originally Posted by John Sincerbeaux View Post
    I donít think that is normal? It definitely should not be dimming your lights. I run a 25Ē SAC 10hp using a 10HP PP. Check your pneumatic pressure on your belt tracking/tension. Maybe back off the pressure a bit? That made a difference on my machineís start up. Also, I always start the feed belt motor first followed by the wide belt motor.
    Hope that helps.
    Thanks for the tip! Iíll try the air pressure.

  11. #11
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    100 amps into the shop is a little light if it includes the lights, DC, and other stuff. I run my small compressor with the WB. A 5 hp DC can barely keep up with a 37" WB so you need to be careful to not take too much cut with the machine, both for dust and for amps. Dave

  12. #12
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    Quote Originally Posted by Toby Jutras View Post
    The whole shop is on a 100 amp feed from the house
    Voltage drop depends on current, wire size, and length of the conductors.

    I also run 100 amps, 250' underground, another 50-60' to the biggest motors. I oversize wiring significantly to eliminate any detectable light dimming. (there are voltage drop calculators online) So far I've seen no dimming.

    JKJ

  13. #13
    Thanks to all that contributed. I was able to speak with Grizzly, and tightened some electrical connections. The spikes are still high (2-3x running amps), but tightening the connections seems to have helped.

    I don't have much of a problem running dust collection (3HP, 2,500 CFM Grizzly), Compressor (5HP IR) and shop lights. I've even started the sander with the compressor running inadvertently, but will generally try to start the sander first.

    Here is quick vid of the startup in the event it helps someone in the future:


    Toby

    https://www.youtube.com/watch?v=dXqT95fCxG4

  14. #14
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    Check your filters regularly. Your DC operating range probably tops out at about 1200 cfm, especially since you transition to three 4" ports. If the cyclone allows fine dust into the filters, the CFM will drop quickly and you will need a map to find the stop button. Dave

  15. #15
    Quote Originally Posted by Toby Jutras View Post
    Thanks to all that contributed. I was able to speak with Grizzly, and tightened some electrical connections. The spikes are still high (2-3x running amps), but tightening the connections seems to have helped.

    I don't have much of a problem running dust collection (3HP, 2,500 CFM Grizzly), Compressor (5HP IR) and shop lights. I've even started the sander with the compressor running inadvertently, but will generally try to start the sander first.

    Toby
    Starting current 2 - 3 time full load amps isn't even remotely high. It probably is much higher than the display says because it doesn't react fast enough. Nothing to worry about there. As for it drawing 25A at idle, I can't comment on that.

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