WEG CFW-11 User Manual page 11

General Instructions
DC Bus: Inverter intermediate circuit; DC voltage obtained from the rectification of the AC input voltage or
from an external power supply; feeds the output inverter bridge with IGBTs.
Power modules U, V, and W: Set of two IGBTs of the inverter output phases U, V, and W.
IGBT: Insulated Gate Bipolar Transistor; basic component of the output inverter bridge. The IGBT works as an
electronic switch in the saturated (closed switch) and cut-off (open switch) modes.
Braking IGBT: Works as a switch to activate the braking resistors. It is controlled by the DC bus voltage
level.
2
PTC: Resistor which resistance value in ohms increases proportionally to the temperature increase; used as a
temperature sensor in electrical motors.
NTC: Resistor which resistance value in ohms decreases proportionally to the temperature increase; used as a
temperature sensor in power modules.
HMI - Human Machine Interface: it is a device that allows the motor control, and the visualization and
modification of the inverter parameters. The CFW-11 HMI presents keys for the motor command, navigation
keys and a graphic LCD display.
FLASH memory: Non-volatile memory that can be electronically written and erased.
RAM memory: Random Access Memory (volatile).
USB: Universal Serial Bus; is a serial bus standard that allows devices to be connected using the "Plug and
Play" concept.
PE: Protective Earth.
RFI Filter: Radio-Frequency Interference Filter for interference reduction in the Radio-Frequency range.
PWM: Pulse Width Modulation; pulsed voltage that feeds the motor.
Switching frequency: Frequency of the IGBTs switching in the inverter bridge, normally expressed in kHz.
General enable: When activated, this function accelerates the motor via acceleration ramp set in the inverter.
When deactivated, this function immediately blocks the PWM pulses. The general enable function may be
controlled through a digital input set to this function or via serial communication.
Start/Stop: When enabled in the inverter (start), this function accelerates the motor via acceleration ramp up
to the speed reference. When disabled (stop), this function decelerates the motor via deceleration ramp up to
the complete motor stop; at this point, the PWM pulses are blocked. The start/stop function may be controlled
through a digital input set for this function or via serial communication. The operator keys
(Stop) of the keypad work in a similar way.
Heatsink: Metal device designed to dissipate the heat generated by the power semiconductors.
2-2
(Start) and