Thus, the rule of thumb for sizing the single phase input on a three-phase drive is to use a VFD rated for 2 times the FLA of the motor. For example if your motor is a 10 HP motor with a FLA of 28 amps, then you would need to select a VFD with an amp rating of 56 amps which ends up being around 20 HP.
Can any motor be used with a VFD?
Output voltages are available for VFDs to match almost any existing motor voltage. However, very few, if any, VFDs have a direct 13,800-volt output for very high-voltage motors. For these cases, using a step-up transformer on the output of the VFD is often necessary to match the motor voltage.
How do I choose a motor drive?
Tips to choose Motor drivers
- Maximum Supply Voltage.
- Maximum Output Current.
- Rated Power Dissipation.
- Load Voltage.
- Packaging Type.
- Number Of Outputs.
How do you select a VFD for a pump?
The most important consideration when choosing a Variable Frequency Drive (VFD) is to know the type of load that is being applied to the motor because it will determine the size and cost of the VFD. The VFD must have sufficient current capability so that the motor can produce the required torque for the load.
How do you measure a VFD?
Sizing of a VFD is based on the rating of the VFD and the motor load. When the VFD is rated in horsepower (or in horsepower and output current), the VFD must be sized to be greater than or equal to the horsepower rating of the motor (or motors).
Can you use a VFD on any 3 phase motor?
Yes, a VFD can power a three-phase motor with a single-phase input power supply, but phase conversion introduces many considerations that normally don’t factor in to buying a VFD.
Which VFD is best?
In low voltage VFDs, we think the best VFDS on the market are the WEG VFD, the Yaskawa VFD, the Toshiba VFD, the LSIS VFD, and the Teco VFD (especially in the high horsepower low voltage models) All of these are good companies with well designed reliable equipment.
How much does a VFD cost?
Typical installed costs of VFD systems range from $200 to $500 per horsepower (HP). Suppliers can assist users in selecting a VFD that is properly sized and that includes any necessary filters and reactors.
How much can you overspeed a motor with a VFD?
Motors generally have to withstand 10 % overspeed. But it in no way means many motors cannot withstand much higher over speeds.
Can you oversize a VFD?
An oversized VFD can be used for a smaller HP motor. The advantage of this application is that if the motor requirements increase, the VFD may be large enough to still handle the increased load.
How long does a VFD last?
The Short Answer
Most manufacturers will admit the typical life expectancy is about 7-12 years … but there are many factors at play. VFD components like fans and capacitors have a finite life and starting at about 5 years, these components can start to fail and will need to be replaced.