Connection of stand-alone option units
57
2
2.9
Connection of stand-alone option units
The inverter accepts a variety of stand-alone option units as required.
Incorrect connection will cause inverter damage or accident. Connect and operate the option unit carefully in accordance with
the corresponding option unit manual.
2.9.1
Connection of the brake unit (FR-BU2)
Connect the brake unit (FR-BU2(H)) as shown below to improve the braking capability during deceleration.
Connection example with the GRZG type discharging resistor
NOTE
• Set "1" in
Pr.0 Brake mode selection
of the FR-BU2 to use a GRZG type discharging resistor.
• Do not remove the jumper across terminals P/+ and P1.
When wiring, make sure to match the terminal symbol (P/+, N/-) at the inverter side and at the brake unit (FR-BU2) side.
(Incorrect connection will damage the inverter and brake unit.)
Install a stepdown transformer.
The wiring distance between the inverter and brake unit (FR-BU2), and between the brake unit (FR-BU2) and
discharging resistor must be within 5 m. Even when the wires are twisted, the cable length must be within 10 m.
It is recommended to install an external thermal relay to prevent overheat of the discharging resistor.
For the connection method of the discharging resistor, refer to the Instruction Manual of the FR-BU2.
• Recommended external thermal relay
∗4
∗1
∗3
∗5
U
V
W
P/+
N/-
R/L1
S/L2
T/L3
Motor
M
Inverter
PR
N/-
BUE
SD
P/+
A
B
C
FR-BU2
GRZG type
discharging
resistor
R
R
Three-phase AC
power supply
MCCB
MC
OFF
ON
MC
T
10 m or less
OCR
contact
MC
External thermal
relay
OCR
∗2
∗1
∗3
Brake unit
Discharging resistor
Recommended
external thermal relay
FR-BU2-H7.5K
GRZG 200-10
Ω
(six in series)
TH-T25-3.6A
FR-BU2-H15K
GRZG 300-5
Ω
(eight in series)
TH-T25-6.6A
FR-BU2-H30K
GRZG 400-2
Ω
(twelve in series)
TH-T25-11A
To a resistor
1/L
1
5/L
3
2/T
1
6/T
3
To the brake
unit terminal P/+