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Recent content by Jraef
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Single phase motor 2 speed, how to reduce speed further?
It depends, but there is a 67% chance that it will not work. This motor has a capacitor and most likely that means it is a Cap-Start / Induction-Run (CSIR), or Cap-Start / Cap-Run (CSCR) type single phase motor. In those types, there is a centrifugal switch that engages the starting capacitor...- Jraef
- Post #4
- Forum: Transformers, Phase Converters and VFD
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Wiring a VFD to a receptacle a viable option? (Bridgeport)
If you have controls on the mill now that are just Across-the-Line starters, when you energize those motors, they will want to pull 600% oif their rated current on startup. A VFD, if sized for the motor HP, is only capable of around 200% current for a few seconds. So to allow it to function with...- Jraef
- Post #37
- Forum: Transformers, Phase Converters and VFD
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220v single phase to 220v three phase
A motor wired for 240 but fed only 120 will likely spin, but the peak torque will be 1/4th of what it should be. So under anything close to less than half of its rated load, it will slow down, pull high current and overload. But if the load is extremely light, it might go unnoticed. I’ve come...- Jraef
- Post #9
- Forum: Transformers, Phase Converters and VFD
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Electrical service 120/240 1-ph, 208/120 3ph, or 480/277 3ph
If it’s just the one machine that needs 3 phase and you have no plans to change that, the phase converter might be the simplest. Forget the delta power options, the CNC will have inverters inside for the spindle and servos, inverters do NOT like delta power sources of any sort. Also, despite...- Jraef
- Post #12
- Forum: Transformers, Phase Converters and VFD
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220V VFD for 220/380V 3phase motor
One of the reasons why Huanyang drives are banned from discussion here is because they are notoriously bad and offer zero support and assistance to buyers. They undercut other reputable drive manufacturers by relying on good Samaritans like the people on this site to assist their buyers, for free.- Jraef
- Post #15
- Forum: Transformers, Phase Converters and VFD
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Wiring 2 speed motor to VFD
But again, don’t miss the IMPORTANT fact that with the VFD in the circuit, you can NEVER switch speeds using the barrel switches while running, you will damage the transistors on the VFD output.- Jraef
- Post #19
- Forum: Transformers, Phase Converters and VFD
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Can all VFDs convert single phase to 3 phase?
The fault is irrelevant in this case, you are not wanting to run the motor while reforming. You are still reforming the caps even if the drive is faulted.- Jraef
- Post #21
- Forum: Transformers, Phase Converters and VFD
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Stop button issues on reverse direction
It might also be an issue with the mechanical interlock between the contactors, that it is misaligned and jamming, or is worn out. So you are cutting power to the coil, but the mechanical interlock is not allowing the contactor to drop out. Not sure why wiggling the button would have an effect...- Jraef
- Post #4
- Forum: Transformers, Phase Converters and VFD
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Contactor Sizing
The ACTUAL power it will draw from the line is simply the motor Amps x 1.732 / the VFD efficiency, which is likely around 97%. But that is meaningless from a Code compliance standpoint, you are REQUIRED to size the branch circuit feeding the VFD by the rules (NEC 430.122). In the drive data...- Jraef
- Post #25
- Forum: Transformers, Phase Converters and VFD
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VFD's "burn up" a motor?
The phenomenon that can damage motors is related to how a VFD functions to "trick" a motor into thinking it is getting a lower voltage along with the change in frequency using a technique called "PWM" (Pulse Width Modulation). Essentially the motor is getting a string of high speed DC pulses...- Jraef
- Post #4
- Forum: Transformers, Phase Converters and VFD
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How to slowly ramp up RPMs on motor
Just get a 500W rheostat to use as the control device.- Jraef
- Post #15
- Forum: Transformers, Phase Converters and VFD
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3-Phase Disconnects(?) on Rochester NY Craigslist
The one on the left is a 30A fused disconnect, the other two are NEMA Size 1 motor starters, not reversing.- Jraef
- Post #2
- Forum: Transformers, Phase Converters and VFD
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Can all VFDs convert single phase to 3 phase?
BE CAREFUL! The ACS400 series was obsoleted over 20 years ago, so it is HIGHLY likely that this drive has been sitting unpowered for years. When that happens, you MUST perform what is called a "capacitor reforming procedure" on the drive PRIOR TO EVEN CONNECTING LINE POWER TO IT! Even applying...- Jraef
- Post #12
- Forum: Transformers, Phase Converters and VFD
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Powermatic lathe VFD-b error when resetting parameters
If it sat for 2 years or longer with no power on it, the DC bus capacitors may have shorted and the drive is dead now, so the display is basically telling you it is an unrecoverable error. Drives that have sat with no power on them for over a year (maybe 2) must be given a "capacitor reforming...- Jraef
- Post #6
- Forum: Transformers, Phase Converters and VFD
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VFD and 3ph AC Motor - Nameplate shows PWM and CSI ratings?
At or below the design motor base speed, the motor torque remains constant as the speed changes, because the V/Hz ratio is kept constant (other than the issue johansen mentions). So voltage varies along with Hz and because HP is a mechanical description of torque and speed, the HP is changing...- Jraef
- Post #18
- Forum: Transformers, Phase Converters and VFD