Connection Of The Brake Unit (Fr-Bu) - Mitsubishi Electric FR-A820-00046 Instruction Manual

Installation and wiring
2.10.3

Connection of the brake unit (FR-BU)

Connect the brake unit (FR-BU2(H)) as shown below to improve the braking capability during decel-
eration.
The FR-BU is compatible with FR-A820-03160(55K) or lower and FR-A840-01800(55K) and lower.
Three-phase AC
power supply
Fig. 2-62:
When wiring, make sure to match the terminal symbol (P/+, N/-) at the inverter side and at the
brake unit (FR-BU(H)) side. (Incorrect connection will damage the inverter.)
When the power supply is 400 V class, install a stepdown transformer.
For the FR-A820-00490(7.5K) or lower and FR-A840-00250(7.5K) or lower, be sure to remove the
jumper across terminals PR and PX.
The wiring distance between the inverter and brake unit (FR-BU2), and between the brake unit
(FR-BU) and discharging resistor unit (FR-BR) must be within 5 m each. Even when the cable is
twisted, the wiring length must be within 10 m.
NOTES If the transistors in the brake unit should becomes faulty, the resistor will overheat. Install a mag-
netic contactor on the inverter's input side and configure a circuit that shut off the current in case
of a fault.
Do not remove the jumper across terminals P/+ and P1 except when connecting a DC reactor
(FR-HEL).
FR-A800
Connection with the brake unit FR-BU
Connection of stand-alone option units
Motor
M
Inverter
≤ 10 m
ON OFF
I001640E
2 - 85