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 (FR-A720-02150 (FR-A740-01100) 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
Be sure to remove the jumper across terminals PR and PX when using the FR-BU with the inverter of FR-A720-00330 (FR-A740-
00170) o lower.
*4
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.
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 (16.4 feet)
or less
ON
OFF
MC
TH1
TH2
HA
HB
HC
45
2