Connection Of The Brake Unit (Fr-Bu); Connection Of The Brake Unit (Bu Type) - Mitsubishi Electric FR-F800 Instruction Manual

2.8.2

Connection of the brake unit (FR-BU)

Connect the brake unit (FR-BU2(H)) as shown below to improve the braking capability during deceleration.
The FR-BU is compatible with FR-F820-02330(55K) or lower and FR-F840-01160(55K) and lower.
Three-phase AC
power supply

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.

The wiring distance between the inverter and brake unit (FR-BU2), and between the brake unit (FR-BU2) and discharging resistor must be within
5 m. Even when the cable is twisted, the wiring length must be within 10 m.
NOTE
• If the transistors in the brake unit should becomes faulty, the resistor will overheat. Install a magnetic 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).
2.8.3

Connection of the brake unit (BU type)

Connect the brake unit (BU type) correctly as shown below. Incorrect connection will damage the inverter. 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-F820-02330(55K) or lower and FR-F840-01160(55K) and lower.
MCCB
Three-phase
AC power
supply

When the power supply is 400 V class, install a stepdown transformer.
NOTE
• 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. 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).
MC
MCCB
R/L1
S/L2
T/L3
Inverter
T ∗1
Inverter
MC
R/L1
S/L2
T/L3
Connection of stand-alone option units
T ∗2
MC
Motor
U
P
V
M
PR
W
PR
P/+ P/+
∗1
N/- N/-
∗3
10 m or less
ON
MC
MC
Motor
U
V M
Brake unit
W
(BU type)
N/-
N
OCR
P/+
Discharging
OCR
resistor
PR
P
INSTALLATION AND WIRING
ON OFF
MC
FR-BR
TH1
TH2
FR-BU
HA
HB
HC
OFF
Remove the
jumper
TB
HC
HB
HA
PC
Fit a jumper
2
65