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B. The drive shall utilize Insulated Gate Bipolar Transistor (IGBT's) in its power
section.
C. The E3 VFD shall have 3 basic design criteria
Rectifier Section that shall include diode bridge rectifier to convert AC to
1)
DC.
Filtering Section that shall include capacitors to eliminate "ripple" affect on
2)
the DC bus to produce smooth DC bus voltage.
Switching Section that shall included Insulated Gate Bipolar Transistors
3)
(IGBT) to provided Pulse Width Modulation.
2.2 Ratings and overload capability of the VFD
A. The drive main input power shall be:
I.
II.
B. The drive shall have a tolerance for voltage ± 10% and frequency ± 2Hz.
C. The drive overload current shall be 100% continuous and 110% for 1 minute.
D. The drive should have a common design for all horsepower models:
230V – 3 through 60HP
460V – 5 through 125HP
2.3 Control Features
A. The drive shall have True Torque Control with Automatic energy-saving control.
B. The drive shall have two (2) frequency priority selection feature.
C. The drive shall be capable of setting both upper and lower limit frequencies.
D. The ASD shall automatically adjust the PWM carrier frequency proportional to
speed. The range of automatic adjustment shall vary from 15khz to .5khz. The
minimum acceptable full speed carrier frequency (60 Hz) with no derating shall
be 8 kHz.
E. The drive shall be capable of PID set point control.
F. Preset macros for typical HVAC applications such as pumps, fans, cooling
towers.
G. Serial RS232C communications standard.
H. Automatic cooling fan control based on heat sink temperature for extended fan
life.
I. The drive shall be able to start and stop from a two-wire control (dry contacts),
three wire momentary contact closure, keypad, and serial interface.
J. The drive shall be able to act as a space heater for a motor when the system is not
running.
K. The drive shall have adjustable input and output terminal response time selections
to prevent noise effects and chattering.
L. The drive shall have a built-in control system for commercial power/inverter
power switching.
200V/50Hz or 200V-230V/60Hz for 230V models
380V-415V/50Hz or 400V-460V/60Hz for 460V models
2
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