Connection of stand-alone option units
(2) Connection with the MT-BU5 (FR-A720-02800 (FR-A740-01440) or more)
After making sure that the MT-BU5 is properly connected, set the following parameters.
Pr. 30 Regenerative function selection = "1"
Pr. 70 Special regenerative brake duty = "10%" (Refer to page 211)
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).
<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.
Do not connect the MT-BU5 to a CN8 connector of the FR-A740-01100.
46
MC
R/L1
S/L2
T/L3
Inverter
CN8
Make cuts in
rubber bush
Wire clamp
T
*1
Motor
U
V
IM
W
P/+
P
N/
PR
P
PR
Brake unit
MT-BU5
Rubber bushes
ON
OFF
CR1
CR2
MC
MC
*2
5m(16.4feet)
or less
TH1
P
PR
TH2
TH1
P
PR
TH2
Resistor unit
MT-BR5
Insert the connector until
you hear a click sound.
CR1
CR2