2010年3月1日 · Assuming the motors don't slip the situation is almost academic. In industrial situations we will often choose the arrangement depending on the power supply available, higher voltage controls usually being more efficient. As an example I recently worked on a dock side crane. There are 16 driven gantry wheels running on rails.

2024年12月14日 · It also breaks the dependency on fast rotor speeds to attain higher efficiency. Synchronous motors are capable of producing near-perfect conversion of electrical and mechanical energy, making up to 99% efficiency rates possible. Synchronous motors can also provide higher power with more compact designs, as well as superior torque at lower speeds.

2009年2月26日 · Tesla Motors spent a lot of engineering time on such issues. Suggest a sun/planet speed reduction gear set with 3 motors driving 3 planet gears, all operating at the same commanded speed. Gives you the conventional drive train and with overriding clutches reduncancy for get-home if one or two motors or controllers fail. Just a thought.

2007年11月5日 · You can put in the best motors and if the rest is crud...well you know... I standardized on Baldor and I'm extremely pleased with their washdown motors. Stainless housing with welded on peckerhead. TEFC or TENV. Hard to kill. Good quality. One thing to be aware of...Washdown motors do not shed heat as well and run a little hotter.

2011年8月9日 · More than 95% of the motors there are still being used from the starting of the refinery, even after the whole refinery went under 7-10 feet salty water in a severe cyclone (hurricane) in 1991. The electrical maintenance group of the refinery has its own repairing facilities and most of motors required several major repairing throughout their life.

2010年12月6日 · If your application falls within the guidelines below, there is no need to apply an inverter-duty motor. NOTE: Marathon inverter-duty motors have limitations as well. Please see the Marathon section for more details. Background: AC motors can be driven by across-the-line contactors and starters. The electricity sent to the motor is a very clean ...

2009年8月12日 · I agree with your comments re control via VFD - essentially good control and no problems in my experience. The soft start may have the effect of prolonging stall currents at the varying voltages when starting slowly causing local heating which may damage the windings, the VFD offers 'at speed' control, efficiency and current draw with good torque.

2024年12月20日 · Specification say, "All LV Motors shall be premium-efficiency (IE3) except for duty service <10% (e.g. davit crane). Also the spec says all the motors shall be rated for continuous duty S1" The vendor is offering a S2 rated motor for a davit crane and this crane operates only for less than 30 minutes.

2009年9月27日 · tedi; there are permanent magnet DC motors that use a full wave diode bridge to change the AC to DC to run the motor, by reversing the DC output of the bridge this will reverse motor direction. there are AC,DC universal motors, 110, or 220 volt that need the field winding reverse to make the motor run in different direction, a DPDT switch would ...

2010年10月21日 · The 20HP motors on one skid had to be replaced with 30HP units to do what 20HP units had done before all the concern over efficiency ratings. On another, a 5HP motor had to be replaced with 7.5HP to do what 5HP had done in the past. And, there is no over driving them. With a VFD I have run motors on pumps up to 120HZ with no problems.