Connection Of The Brake Unit (Fr-Bu/Mt-Bu5) - Mitsubishi FR-F720-00046-NA Instruction Manual

Connection of stand-alone option units
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 (FR-F720-02330 (FR-F740-01160) or lower)
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(16.4
feet). If twisted wires are used, the distance should be within 10m(32.8feet).
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 (FR-F720-03160 (FR-F740-01800) or higher)
After making sure that the wiring is correct, set "1" in Pr.30 Regenerative function selection. (Refer to page 115)
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(32.8feet) maximum when
wires are twisted and 5m(16.4feet) 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).
38
MCCB
T
MC
U
R/L1
V
S/L2
W
T/L3
Inverter
P/+
N/
CN8
T
*2
MC
Motor
R/L1 U
S/L2 V
IM
T/L3 W
Inverter
*1
N/−
*3
5m (16.4feet)
or less
*1
ON
Motor
IM
MC
5m(16.4feet)
or less
P
PR
P
PR
Brake unit
MT-BU5
ON OFF
MC
FR-BR
P TH1
PR
TH2
FR-BU
PR
HA
P/+
HB
*1
N/−
HC
OFF CR1 CR2
MC
*2
CR1
TH1
P
PR
TH2
CR2
TH1
P
PR
TH2
Resistor unit
MT-BR5