Braking Resistor Installation; Install A Braking Resistor: Erf-Type; Install A Braking Resistor Unit: Lkeb-Type - YASKAWA GA800 Series Technical Reference

3.9 Braking Resistor Installation

3.9

Braking Resistor Installation

A braking resistor or braking resistor unit (dynamic braking option) helps stop the motor quickly and smoothly when
there is high load inertia. If you try to decelerate a motor in less time than usual for a coast to stop, the motor will
rotate faster than the synchronous speed that aligns with the set frequency. This will cause the motor to become an
induction generator. The inertia energy of the motor and regenerate to the drive and charge the drive DC bus capacitor
and increase the voltage. If the voltage is more than the overvoltage level, an ov [Overvoltage] will occur. To prevent
these overvoltage faults, a dynamic braking option is necessary.
WARNING!
Set L3-04 = 0 [Stall Prevention during Decel = Disabled] when you operate the drive with:
• a regenerative converter
• regenerative unit
• braking unit
• braking resistor
• braking resistor unit.
If you set the parameter incorrectly, the drive can decelerate for too long and cause serious injury or death.
NOTICE: Damage to Equipment. Before you connect a dynamic braking option to the drive, make sure that qualified personnel read
and obey the Braking Unit and Braking Resistor Unit Installation Manual (TOBPC72060001). If you do not read and obey the
manual or if personnel are not qualified, it can cause damage to the drive and braking circuit.
Note:
• Select the correct braking circuit size to dissipate the power that is necessary to decelerate the load in the correct time. Before you run the
drive, make sure that the braking circuit can dissipate the energy for the set deceleration time.
• To install a dynamic braking option, set L8-01 = 0 [3% ERF DB Resistor Protection = Disabled].
WARNING! Fire Hazard. Do not connect a braking resistor to terminals +1 or -. Use terminals B1 and B2 for the braking resistor
connections. If you connect a braking resistor to the incorrect terminals, it can cause damage to the drive and braking circuit and
serious injury or death.
NOTICE: Connect braking resistors to the drive as shown in the connection diagram examples. If you wire the braking circuits
incorrectly, it can cause damage to the drive or equipment.
To connect a Yaskawa ERF series braking resistor to the drive, set L8-01 = 1 [Enabled].
To use a non-ERF type braking resistor, connect a thermal overload relay between the drive and the braking resistor,
and set a circuit to de-energize the drive at the trip contacts of the thermal overload relay.
◆

Install a Braking Resistor: ERF-Type

Connect the braking resistor to drive models 2004 to 2021 and 4002 to 4012 as shown in
When you use a braking resistor, set L8-01 = 1 [3% ERF DB Resistor Protection = Enabled] and set one of the
MFDO parameters H2-01 to H2-03 = D [MFDO Function Select = Braking Resistor Fault]. Use a sequence that uses
MFDO to de-energize the drive.
◆

Install a Braking Resistor Unit: LKEB-Type

Connect the braking resistor unit as shown in
DB Resistor Protection = Disabled].
Models 2004 to 2138 and 4002 to 4168 have a built-in braking transistor.
To prevent overheating the braking resistor unit, set a sequence to de-energize the drive at the trip contacts of the
thermal overload relay.
108
Figure 3.56 Install a Braking Resistor: ERF-Type
Figure 3.57. To install a braking resistor unit, set L8-01 = 0 [3% ERF
Figure
YASKAWA SIEPC71061737B GA800 Drive Technical Reference
3.56.