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Type: Posts; User: Jraef

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  1. Replies
    29$$
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    1,986

    I think it's worth asking. 250 in.-lbs. is only...

    I think it's worth asking. 250 in.-lbs. is only about 21 ft.-lbs., it's not that much. I'm wondering if that was the problem here.
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    3$$
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    122

    The difference is, you will need a 2 pole circuit...

    The difference is, you will need a 2 pole circuit breaker for the 480V feed, vs a 1 pole breaker for a 277V feed. Same number of conductors of course, but you take up more space in your panelboard.
  3. Replies
    4$$
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    133

    It used to be that VFDs did not come with Motor...

    It used to be that VFDs did not come with Motor Thermal Overload Protection built-in, and standard bi-metal thermal OL relays have a tendency to nuisance trip on the output of VFDs, so the embedded...
  4. Replies
    5$$
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    221

    And if you put disconnects at the motor, run a...

    And if you put disconnects at the motor, run a couple of control wires to an aux contact of the disconnect that then get wired to the Enable input of the VFD (assuming it has one) so that if someone...
  5. Replies
    8$$
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    500

    Yeah, you're right, similar issue. And no, I...

    Yeah, you're right, similar issue.

    And no, I don't mind using classified breakers. So I guess I'm a hypocrite...
  6. Replies
    5$$
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    221

    Replace it. There is NO legal use for an MCP...

    Replace it. There is NO legal use for an MCP outside of a factory assembled combination motor starter. They cannot be used as a feeder in any way, shape or form.
    It used to be, a few years ago,...
  7. Replies
    5$$
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    221

    You cannot "legally" put them in the MCC...

    You cannot "legally" put them in the MCC yourself, the only power devices that can go in MCCs are those built by the MCC mfr. That doesn't mean it can't be done, but you would be voiding the UL...
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    8$$
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    310

    If used on the output of a VFD or anything else...

    If used on the output of a VFD or anything else that uses PWM (such as an on-line UPS, servo amplifier etc.), steel conduit shields about 95% of the EMI/RFI radiation from the conductors. Aluminum...
  9. Replies
    8$$
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    500

    The devices referenced in your post are not for...

    The devices referenced in your post are not for this purpose, they are for transitioning from Al to Cu wire. So the Cu pigtail is smaller than the side for the stranded Al wire, it's not for...
  10. Replies
    17$$
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    678

    In a resistive load where the resistance remains...

    In a resistive load where the resistance remains the same, the lower voltage results in a lower wattage.

    P (watts) = E (voltage)2 / R (ohms)

    Since you already have the heater, the R is already...
  11. Replies
    20$$
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    1,121

    There are 4 different treadmills on my local...

    There are 4 different treadmills on my local Craiglist today, all in working condition, totally free to whomever comes to haul them away.

    I wonder just how many of those things are bought, used...
  12. Replies
    2$$
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    252

    When Siemens first bought out Furnas and started...

    When Siemens first bought out Furnas and started selling the Furnas Pump Panels, they would have definitely had the old Furnas ESP100 SSOL relays that were always CT based. But about 15 years ago...
  13. Replies
    24$$
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    1,054

    To this point, the new energy efficient...

    To this point, the new energy efficient transformers will be labeled as meeting “NEMA TP-1-2002” specifications. So if you are curious, get the specs on the new transformer and see if it says that...
  14. The manual starter can be though of as...

    The manual starter can be though of as “supplemental protection” for the solenoid coil. Not required by code and it would not suffice as the Branch Over Current Protective Device since it’s not a...
  15. Replies
    6$$
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    443

    This is the best answer really. In days gone by...

    This is the best answer really. In days gone by we in the industrial business used more of what is called “common control”, meaning your control circuit voltage was common to the line voltage, ie...
  16. Replies
    11$$
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    770

    I was part of that “price per section” crowd back...

    I was part of that “price per section” crowd back then when I was an MCC specialist for an AB distributor and then later for another mfr.. I kept records of all of my successful bids and noticed that...
  17. Replies
    3$$
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    261

    But definitely don’t leave the starters there and...

    But definitely don’t leave the starters there and feed the VFDs from the starters. It’s OK to cycle power to VFDs with a contactor or breaker occasionally, but doing it all the time will eventually...
  18. Thread: VFD cable types

    by Jraef
    Replies
    7$$
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    485

    It’s a well known and documented problem, it ONLY...

    It’s a well known and documented problem, it ONLY applies to the OUTPUT conductors. The issue is that thermoplastic insulation such as PVC (as used in THHN) is manufactured as a liquid that is...
  19. Replies
    9$$
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    629

    Yes, but the added problems with VFD outputs have...

    Yes, but the added problems with VFD outputs have to do with the fact that the output sine waves are no longer the same, so adjacent magnetic fields that would normally cancel each other out, will...
  20. Replies
    32$$
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    1,407

    This issue is not part of the NEC (NFPA70), which...

    This issue is not part of the NEC (NFPA70), which would only address the HOW part of installing switches and lights. The WHY part is typically enforced by NFPA 101, the Life Safety Code (LSC) and...
  21. Replies
    24$$
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    1,054

    Remember, Watts = Amps x Volts x Power Factor...

    Remember, Watts = Amps x Volts x Power Factor (x1.732 for 3 phase). The current readings are relatively meaningless because the Power Factor on an unloaded transformer is likely very low, maybe even...
  22. XLPE (Cross-Linked Poly Ethylene) insulation is...

    XLPE (Cross-Linked Poly Ethylene) insulation is found in XHHW, or RHH/RHW conductor types and generally exceeds the specs of standard building wire like THHN/THWN, which have simpler PVC insulation,...
  23. Replies
    11$$
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    538

    Yes, I cannot imagine that it is less expensive...

    Yes, I cannot imagine that it is less expensive to rewind a 5HP motor than it is to just buy one with the right specs, or just buy a transformer for it. Or, if you are buying a transformer anyway,...
  24. Replies
    20$$
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    1,121

    Where the nameplate says "Wound SH", that means...

    Where the nameplate says "Wound SH", that means it is a Shunt wound DC motor, meaning the Field is a separate Shunt winding. When they show the Field as "150/300", that means it is a 300V wound Field...
  25. Replies
    7$$
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    360

    No, no problem at all. In fact, how else would...

    No, no problem at all. In fact, how else would you do it?
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