Connection Of The Brake Unit (Fr-Bu/Mt-Bu5) - Mitsubishi Electric FR-A720-0.4K Instruction Manual

2.5.3

Connection of the brake unit (FR-BU/MT-BU5)

When connecting the brake unit (FR-BU(H)/MT-BU5) to improve the brake capability at deceleration, make connection
as shown below.
(1) Connection with the FR-BU (55K or less)
Three-phase AC
power supply
*1 Connect the inverter terminals (P/+, N/-) and brake unit (FR-BU (H)) terminals so that their terminal signals match with each other.
(Incorrect connection will damage the inverter.)
*2 When the power supply is 400V class, install a step-down transformer.
*3 Be sure to remove a jumper across terminal PR-PX when using the FR-BU with the inverter of 7.5K or less.
*4 The wiring distance between the inverter, brake unit (FR-BU) and resistor unit (FR-BR) should be within 5m. If twisted wires are
used, the distance should be within 10m.
CAUTION
⋅ If the transistors in the brake unit should become faulty, the resistor can be unusually hot, causing a fire. Therefore, install a
magnetic contactor on the inverter's input side to configure a circuit so that a current is shut off in case of fault.
⋅ Do not remove a jumper across terminal P/+ and P1 except when connecting a DC reactor.
MCCB
R/L1
S/L2
T/L3
Inverter
PR
*3
PX
Connection of stand-alone option units
T
*2
MC
FR-BR
Motor
U
P
V
IM
PR
W
FR-BU
PR
P/+
*1
N/− N/−
*4
5m or less
ON OFF
MC
TH1
TH2
HA
HB
HC
47
2