Install Braking Resistor; Installing A Braking Resistor: Erf Type; Installing A Braking Resistor Unit : Lkeb Type - YASKAWA GA700 Technical Manual

2.17

Install Braking Resistor

Braking resistor/braking resistor unit (dynamic braking option) helps bring the motor to a smooth and rapid stop
when working with high load inertia. When an attempt is made to decelerate a motor within an amount of time
that is shorter than it would normally take to coast to stop, the motor will rotate faster than the synchronous speed
that corresponds to the frequency that has been set. This will result in the motor becoming an induction generator.
As a result, the inertia energy of the motor and the load will be regenerated to the drive. At this time, the DC bus
capacitor of the drive is charged, and the voltage rises. Once the overvoltage level is surpassed, an ov [DC Bus
Overvoltage] will occur. To prevent these overvoltage faults, a dynamic braking option is necessary.
NOTICE: Carefully review instruction manual TOBPC72060001 before connecting a dynamic braking option to the drive.
Failure to comply could damage the drive or braking circuit.
Note:
• Properly size the braking circuit to dissipate the power required to decelerate the load in the desired time. Ensure that the braking
circuit can dissipate the energy for the set deceleration time prior to running the drive.
• To install a dynamic braking option, set L8-01 [Internal DB Resistor Protect Sel] = 0.
• Set L3-04 = 0 [Decel Stall Prevention Selection = Disabled] to disable Stall Prevention when using a regenerative converter,
regenerative unit, dynamic braking unit, braking resistor, or braking resistor unit. The drive may not stop within the designated
deceleration time if Stall Prevention is not disabled.
WARNING! Fire Hazard. The braking resistor connection terminals are B1 and B2. Do not connect braking resistors to any
other terminals. Improper wiring connections could cause the braking resistor to overheat and cause death or serious injury by
fire. Failure to comply may result in damage to the braking circuit or drive.
NOTICE: Connect braking resistors to the drive as shown in the I/O wiring examples. Improperly wiring braking circuits could
result in damage to the drive or equipment.
To connect a Yaskawa ERF series braking resistor to the drive, set L8-01 = 1 [Internal DB Resistor Protect Sel =
Provided].
If using a non-ERF type braking resistor, connect a thermal overload relay between the drive and the braking
resistor, and set up a circuit that shuts off power to the drive at the trip contacts of the thermal overload relay.
◆

Installing a Braking Resistor: ERF Type

Connect the braking resistor as shown in the following figure for drive models 2004 to 2021 and 4002 to 4012. To
install a braking resistor, set L8-01 = 1 [Internal DB Resistor Protect Sel = Provided].
◆

Installing a Braking Resistor Unit : LKEB Type

Connect the braking resistor unit as shown in the following figure. To install a braking resistor unit, set L8-01 = 0
[Internal DB Resistor Protect Sel = Not Provided].
Models 2004 to 2138 and 4002 to 4168 have a built-in braking transistor.
To protect the braking resistor unit from overheating, set up a sequence that shuts off the supply of power at the
trip contacts of the thermal overload relay.
YASKAWA ELECTRIC SIEP C710617 01B YASKAWA AC Drive GA700 Technical Manual
Figure 2.60 Installing a Braking Resistor: ERF Type

2.17 Install Braking Resistor

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