Dynamic Braking - Omron 3G3MX2 User Manual

Dynamic Braking

5-3 Dynamic Braking
5-3-1 Introduction
262
Voltage
1-phase 200 VAC
3-phase 200 VAC
3-phase 400 VAC
• The purpose of dynamic braking is to improve the ability of the inverter to
stop (decelerate) the motor and load. This becomes necessary when an
application has some or all of the following characteristics:
• High load inertia compared to the available motor torque
• The application requires frequent or sudden changes in speed
• System losses are not great enough to slow the motor as needed
When the inverter reduces its output frequency to decelerate the load, the
motor can temporarily become a generator. This occurs when the motor rota-
tion frequency is higher than the inverter output frequency. This condition can
cause the inverter DC bus voltage to rise, resulting in an over-voltage trip. In
many applications, the over-voltage condition serves as a warning signal that
we have exceeded the deceleration capabilities of the system. The MX2
inverters have a built-in braking chopper, which sends the regenerative
energy from the motor during deceleration to the optional braking resistor(s).
external braking units may also be used if higher braking torques and/or duty
cycles are required. The dynamic braking resistor serves as a load, develop-
ing heat to stop the motor just as brakes on an automobile develop heat dur-
ing braking.
The braking resistor is the main component of a braking resistor assembly, it
includes a fuse and a thermal relay for safety. And switching circuit and power
resistor are the main components of the dynamic braking unit that includes a
fuse and thermally activated alarm relay for safety. However, be careful to
avoid overheating its resistor. The fuse and thermal relay are safeguards for
extreme conditions, but the inverter can maintain braking usage in a safe
zone.
Inverter model
3G3MX2-AB001
3G3MX2-AB002
3G3MX2-AB004
3G3MX2-AB007
3G3MX2-AB015
3G3MX2-AB022
3G3MX2-A2001
3G3MX2-A2002
3G3MX2-A2004
3G3MX2-A2007
3G3MX2-A2015
3G3MX2-A2022
3G3MX2-A2037
3G3MX2-A2055
3G3MX2-A2075
3G3MX2-A2110
3G3MX2-A2150
3G3MX2-A4004
3G3MX2-A4007
3G3MX2-A4015
3G3MX2-A4022
3G3MX2-A4030
3G3MX2-A4040
3G3MX2-A4055
3G3MX2-A4075
3G3MX2-A4110
3G3MX2-A4150
Section 5-3
DC reactor model
AX-RC10700032-DE
AX-RC06750061-DE
AX-RC03510093-DE
AX-RC02510138-DE
AX-RC01600223-DE
AX-RC21400016-DE
AX-RC10700032-DE
AX-RC06750061-DE
AX-RC03510093-DE
AX-RC02510138-DE
AX-RC01600223-DE
AX-RC01110309-DE
AX-RC00840437-DE
AX-RC00590614-DE
AX-RC00440859-DE
AX-RC43000020-DE
AX-RC27000030-DE
AX-RC14000047-DE
AX-RC10100069-DE
AX-RC08250093-DE
AX-RC06400116-DE
AX-RC04410167-DE
AX-RC03350219-DE
AX-RC02330307-DE
AX-RC01750430-DE