Connection Of The Brake Unit (Fr-Bu/Mt-Bu5) - Mitsubishi F700 Series Instruction Manual

2.4.2

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 (01160 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 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.
(2) Connection with the MT-BU5 (01800 or more)
After making sure that the wiring is correct, set "1" in Pr.30 Regenerative function selection. (Refer to page 108)
MCCB
Three-phase
AC power
supply
*1 When the power supply is 400V class, install a step-down transformer.
*2 The wiring length between the resistor unit and brake resistor should be 10m maximum when wires are
twisted and 5m maximum when wires are not twisted.
CAUTION
 Install the brake unit in a place where a cooling air reaches the brake unit heatsink and within a distance of the cable supplied
with the brake unit reaches the inverter.
 For wiring of the brake unit and inverter, use an accessory cable supplied with the brake unit. Connect the main circuit cable to
the inverter terminals P/+ and N/- and connect the control circuit cable to the CN8 connector inside by making cuts in the
rubber bush at the top of the inverter for leading the cable.
 The brake unit which uses multiple resistor units has terminals equal to the number of resistor units. Connect one resistor unit
to one pair of terminal (P, PR).
MCCB
R/L1
S/L2
T/L3
Inverter
T
*1
MC
U
R/L1
V
S/L2
W
T/L3
Inverter
P/+
N/
CN8
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/−
*3
5m or less
ON OFF
Motor
IM
MC
5m or
*2
less
P
PR
P
PR
Brake unit
MT-BU5
ON OFF
MC
TH1
TH2
HA
HB
*1
HC
CR1 CR2
MC
CR1
TH1
P
PR
TH2
CR2
TH1
P
PR
TH2
Resistor unit
MT-BR5
33
2