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

Connection of stand-alone option units
2.10.4

Connection of the brake unit (BU type)

Connect the brake unit (BU type) correctly as shown below. Incorrect connection will damage the in-
verter. Remove the jumpers across terminals HB and PC and terminals TB and HC of the brake unit and
fit one across terminals PC and TB.
The BU type is compatible with FR-A820-03160(55K) or lower and FR-A840-01800(55K) and lower.
Three-
phase AC
power
supply
Fig. 2-63:
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.
NOTES The wiring distance between the inverter and brake unit (BU type), and between the brake unit
(BU type) and discharging resistor must be within 2 m each. Even when the cable is twisted, the
wiring length must be within 5 m.
If the transistors in the brake unit should becomes faulty, the resistor will overheat and result in a
fire. Install a magnetic contactor on the inverter's input side and configure a circuit that shut off
the current in case of a fault.
Remove the jumper across terminals P/+ and P1 only when connecting a DC reactor (FR-HEL).
2 - 86
MCCB MC
*2
Connection with the brake unit BU
T
Inverter
Motor
U
R/L1
V M
S/L2
W
T/L3
N/-
P/+
PR
Discharging
PX
resistor
Installation and wiring
ON OFF
MC
MC
Brake unit
(BU type) Remove the
jumper
TB
N
HC
OCR
HB
HA
OCR
PC
PR
Fit a jumper
P
I002411E