Terms And Definitions Used In The Manual - WEG CFW-11 User Manual

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2.2 TERMS AND DEFINITIONS USED IN THE MANUAL

Normal Duty Cycle (ND):
and an overload of 110 % during 1 minute.
Duty (ND)). It must be used for driving motors that are not subject in that application to high torques with respect
to their rated torque, when operating at constant speed, during start, acceleration or deceleration.
I : inverter rated current for use with normal duty cycle (ND = Normal Duty).
nom-ND
Overload: 1,1 x I
2
Heavy Duty Cycle (HD):
an overload of 150 % during 1 minute. It is selected by programming P0298 (Application) = 1 (Heavy Duty – HD). It
must be used for driving motors that are subject in that application to high torques with respect to their rated torque,
when operating at constant speed, during start, acceleration or deceleration.
I : inverter rated current for use with heavy duty cycle (HD = Heavy Duty).
nom-HD
Overload: 1,5 x I
Rectifier: the input circuit of the inverters that converts the input AC voltage into DC, it is made of thyristors
and power diodes.
Pre-charge circuit: it charges the DC link capacitors with a limited current, thus avoiding higher current peaks
when powering the inverter.
DC Link: inverter intermediate circuit; DC voltage obtained from the rectification of the AC input voltage or
from an external power supply. It feeds the inverter output IGBT bridge.
U, V and W Arms: set of two IGBTs forming the inverter output phases U, V and W.
IGBT: "Insulated Gate Bipolar Transistor"; it is the output inverter bridge basic component, working as an
electronic switch either in the saturated (closed switch) or in the cut off mode (open switch).
Braking IGBT: it works as a switch to activate the braking resistances; it is controlled by the voltage level on
the DC link.
Gate Driver: circuit used turn the IGBTs on and off.
PWM: "Pulse Width Modulation". A pulsed voltage that feeds the motor.
Switching Frequency: switching frequency of the IGBTs of the inverter bridge, normally expressed in kHz. Also
known as carrier frequency.
2-2 | CFW-11
inverter duty that defines the maximum current values for continuous duty
/ 1minute.
nom-ND
inverter duty that defines the maximum current values for continuous duty
/ 1minute.
nom-HD
It is selected by programming P0298 (Application) = 0 (Normal
I
nom-ND
I and
nom-HD