2007年12月9日 · To convert HZ to spindle RPM you have to know the spindle RPM at a nominal motor RPM. If the motor is rated at 1725 RPM at 60 hz and the spindle is spinning at 500 RPM at 60 hz, then here is the math: 500 spindle rpm / 60 = 8.33 spindle RPM per hz. 90 hz *8.33 = 749.7 (750) spindle RPM. 50 hz * 8.33 = 416.5 (415) spindle RPM.

2011年7月29日 · At the advice of some here I switched out to a 2 pole 3450 RPM motor, final spindle speeds (in high gear) 8 Hz = 350 RPM, 47.5 Hz = 2000 RPM (in back gear) 8 Hz = 36 RPM, 47.5 Hz = 300 RPM. I have enabled vector control and followed the manual to the letter and my results are acceptable, but there is room for improvement.

2008年6月25日 · When using a VFD to drive a given motor at its label rated 60 hz you get the label rated speed from the motor. Lets say that speed is 1200 rpm. What do you get at 30hz - 600 rpm? Does 90 hz give 1800 rpm? Or does something different happen? Thanks in advance.

2007年8月31日 · The old rule of thumb (subject to changes/improvements in VFD design, I suppose) is that a 60 HZ motor on a VFD will have constant torque at less than 60 Hz and constant HP at frequencies greater than 60 HZ. That means a 2 HP 1755 RPM motor at 60, 90 or 120 HZ will still have 2 HP, but, at 30 Hz (878 RPM), will have 1 HP.

2004年8月26日 · If it develops 2 HP at 60 Hz (1750 RPM) it will develop 1 HP at 30 Hz (900) and so on until at 200 RPM (or whatever) the motor devlops HP in proportion to the VFD's set Hz divided by the line Hz. For this reason you still need step pulleys, gears, variable speed V belt or some kind of multi-ratio mechanical drive to give you narrower speed ranges.

2012年1月28日 · I previously ran auto tune using all the nameplate values from the motor (1740 RPM, 60 Hz). Now I'd like to increase the max RPM. So my plan is to go through the auto tune process again, this time setting the frequency and RPM to my desired values. Using: RPM = (120 * Frequency) / # of poles in the motor I get RPM = 1800 @ 60 Hz for my 4 pole ...

2004年5月6日 · At 1 1/2 times 120 Hz (180 Hz) the motor will run to 3450 RPM - at double freq 7100 +/- RPM. This is sound practice. There is no danger of damaging the motor armature or bearings from over-speeding within these limits. In a local electrical drive shop, I saw a 20 HP 3450 RPM motor that set run to 12,000 RPM as a direct drive for a big centrifuge.

2007年1月24日 · Nope. Varable frequency for a single phase motor will work only from the RPM the start switch kicks out to the max RPM/Hz available. That sounds very do-able until you consider that running any single phase motor from a VFD is almost impossible because of the missing leg protection built into every VFD. I don't know.

2008年4月24日 · Go with a 1750 RPM motor and over speed it, they can easily go to 100 or if need 120Hz. Better motors, such as inverter/vector motors are designed for a much wider operation performance window and much higher speeds (6000 RPM for 2 and 3 Hp motors). A standard 3450 RPM can only be over sped by maybe 20%, not recommended.

2007年2月17日 · Low speed depends on the type of VFD. For V/Hz VFDs, you typically wouldn't want to run much below 5-6Hz. Open-loop or sensorless vector VFDs can get you down to around 1Hz, while closed-loop vector (with encoder feedback) can get you down to around 0.1Hz. High speed depends more on the motor.