Standard Motor Catalog

Section TR Technical Reference Guide

ADJUSTABLE SPEED INVERTER DUTY OPERATION PRODUCT NEMA Design does not apply (GE Type KAF) Enclosure: Open Dripproof or Totally-Enclosed Frames: 143-5013 ADJUSTABLE SPEED DRIVE (ASD™) OPERATION Most of today’s state-of-the-art inverter drives uses IGBT technology. These drives solve the electrical noise problem of the older transistor units but can create significant issues for pre-IGBT motor insulation life. The IGBT drive use frequencies that are above the audible range and can cause significant rapid voltage spikes that may shorten motor insulation life. Motor manufacturers, through the National Electric Manufacturers Association (NEMA) technical section have defined IGBT drive output spike voltage as 3.1 times the motor nameplate voltage. Example: NEMA MG-1-31 states 3.1 times the nameplate voltage or 460 volts x 3.1= 1425 minimal acceptable voltage spike @ .01 microsecond rise time. Similarly for 575V; the voltage spike = 575 volts x 3.1 = 1783V Specific to this application, GE uses insulation system to withstand spike voltages up to 2400V. ASD™/LOAD REQUIREMENT DATA SHEET VARIABLE FREQUENCY OPERATION

XSD Ultra ® GEGARD2400 incorporates Class H rated GE701 varnish, which consists of 100% solids and has no solvents that evaporate during the curing cycle. With the use of more sophisticated designs, GE Energy has solved the spiking issue and offers drive products that keep the spike under 1000 volts and are compatible with older existing motors. Besides the motor insulation system, the application should consider the shortest leads possible between the drive and motor (50 ft) and make sure the motor has enough thermal capability to support the application at reduced speeds. The point here is that being IGBT “Compatible” is not necessarily “Invertor Duty”. Standard efficiency motors with appropriate IGBT compatible insulation have as a primary design parameter cost, not variable speed loading capability. Many simple applications can be served with these standard motors but all the parameters must be considered. Some of the most significant are: • Thermal stress for low frequency constant torque loads • Low frequency performance - speed oscillation • Lead length • System information feedback

If any of these items are necessary or unknown the user should consider the true Inverter Duty Motor.

Design Point

Hp @

RPM

Range (Min-Max)

-

RPM

Type Load Variable Torque

Constant Torque

Above Design RPM

Constant Hp

CTq

VTq

ASD Type:

PWM (Pulse Width Modulated)

VSI (6 Step Voltage Inverter)

CSI (6 Step Current Inverter)

Make

Model #

Fill out only the applicable requirements below: Service Factor (sine wave)

(ASD)

Temp Rise (sine wave)

(ASD)

Overload (150% for 1 minute standard): Overload (%) of motor required at top speed: Starting Torque (140% rated torque with 150% Rated Current Standard):

TR.29

Data subject to change without notice. 02/23 • www.gemotorswolong.com