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
1)Rectifier Section that shall include diode bridge rectifier to convert AC to DC.
2)Filtering Section that shall include capacitors to eliminate “ripple” affect on the DC bus to produce smooth DC bus voltage.
3)Switching Section that shall included Insulated Gate Bipolar Transistors (IGBT) to provided Pulse Width Modulation.
2.2Ratings and overload capability of the VFD
A.The drive main input power shall be:
I. 200V/50Hz or
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
2.3Control Features
A.The drive shall have True Torque Control with Automatic
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
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
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