Mitsubishi Electric FR-F720P-0.75K to 110K Instruction Manual page 48

(2) Connection with the MT-BU5 (75K or higher)
After making sure that the wiring is correct, set the following parameters:
⋅ Pr. 30 Regenerative function selection = "1"
⋅ Pr. 70 Special regenerative brake duty = "10%"
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).
<Inserting the CN8 connector>
Make cuts in rubber bush of the upper portion of the inverter and lead a cable.
1) Make cuts in the rubber bush for leading the CN8 connector cable with a nipper or cutter knife.
2) Insert a connector on the MT-BU5 side through a rubber bush to connect to a connector on the inverter side.
CN8 connector
CAUTION
Clamp the CN8 connector cable on the inverter side with a wire clamp securely.
♦ Parameters referred to ♦
Pr.30 Regenerative function selection
Pr.70 Special regenerative brake duty
MC
R/L1
S/L2
W
T/L3
Inverter
P/+
N/
CN8
Rubber bushes
Make cuts in
rubber bush
Wire clamp
Refer to page 125
Refer to page 125
Connection of stand-alone option units
T
*1
ON
Motor
U
V
M
MC
10m or
less
P
PR
P
PR
Brake unit
MT-BU5
OFF CR1 CR2
MC
*2
CR1
TH1
P
PR
TH2
CR2
TH1
P
PR
TH2
Resistor unit
MT-BR5
Insert the connector until
you hear a click sound.
2
37