Issue:
When to use inverter duty rated motors on Schneider Electric drives?
Product Line:
All Schneider Altivar Drives/Drive Systems
Resolution:
A VFD driven general purpose motor can overheat if it is operated at slow speeds. Since most general purpose motors cool themselves with shaft-mounted fans, slow speeds mean less cooling. If the motor overheats, bearing and insulation life will be reduced. Therefore, there are minimum speed requirements for all motors. Inverter-duty motors are designed to operate at slow speeds.
The voltage “chopping” that occurs in the drive sends high-voltage spikes (at the DC bus level) down the wire to the motor. If the system contains long cabling, a reflective wave phenomena can occur at the motor. The reflected wave can effectively double the voltage on the wire and lead to premature failure of the motor insulation. Inverter-duty motors have increased insulation to handle the higher voltage.
General purpose motors can be used with drives in many applications; however, inverter-duty motors are designed to handle much lower speeds without overheating and they are capable of withstanding higher voltage spikes without the insulation failing.
When to use inverter duty rated motors on Schneider Electric drives?
Product Line:
All Schneider Altivar Drives/Drive Systems
Resolution:
A VFD driven general purpose motor can overheat if it is operated at slow speeds. Since most general purpose motors cool themselves with shaft-mounted fans, slow speeds mean less cooling. If the motor overheats, bearing and insulation life will be reduced. Therefore, there are minimum speed requirements for all motors. Inverter-duty motors are designed to operate at slow speeds.
The voltage “chopping” that occurs in the drive sends high-voltage spikes (at the DC bus level) down the wire to the motor. If the system contains long cabling, a reflective wave phenomena can occur at the motor. The reflected wave can effectively double the voltage on the wire and lead to premature failure of the motor insulation. Inverter-duty motors have increased insulation to handle the higher voltage.
General purpose motors can be used with drives in many applications; however, inverter-duty motors are designed to handle much lower speeds without overheating and they are capable of withstanding higher voltage spikes without the insulation failing.
If this article does not answer your question, check out our FAQ database that has answers to more commonly asked questions:
Frequently Asked Questions - Schneider Electric (se.com)
If this FAQ did not solve your issue, you can call us at 1-888-778-2733 Option 2 and then 4 or e-mail us at drive.products.support@se.com to create a case with our Technical Support Team.
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