Mitsubishi Electric FR-A800, Instruction Manual

Page: 112 / 1042

Connection of stand-alone option units Installation and wiring
2 - 82
2.10.2 Connection of the brake unit (FR-BU2)
Connect the brake unit (FR-BU2(H)) as shown below to improve the braking capability during decel-
eration.
Connection example with the GRZG type discharging resistor
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.)
When the power supply is 400 V class, install a stepdown transformer.
Be sure to remove the jumper across terminals PR and PX when using the FR-BU2 with the inverter
of FR-A820-00490(7.5K) or lower, FR-A840-00250(7.5K) or lower.
#
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 each. 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.
I002408E
Fig. 2-59: Connection with the brake unit FR-BU2
Brake unit Discharging resistor
Recommended
external thermal relay
FR-BU2-1.5K GZG 300W-50Ω (one) TH-N20CXHZ 1.3A
FR-BU2-3.7K GRZG 200-10Ω (three in series) TH-N20CXHZ 3.6A
FR-BU2-7.5K GRZG 300-5Ω (four in series) TH-N20CXHZ 6.6A
FR-BU2-15K GRZG 400-2Ω (six in series) TH-N20CXHZ 11A
FR-BU2-H7.5K GRZG 200-10Ω (six in series) TH-N20CXHZ 3.6A
FR-BU2-H15K GRZG 300-5Ω (eight in series) TH-N20CXHZ 6.6A
FR-BU2-H30K GRZG 400-2Ω (twelve in series) TH-N20CXHZ 11A
Tab. 2-46: Recommended external thermal relay
NOTES 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 except when connecting a DC reactor
(FR-HEL).
U
V
W
P/+
N/-
R/L1
S/L2
T/L3
M
PR
N/-
BUE
SD
P/+
A
B
C
FR-BU2
R R
MCCB
MC
MC
T
MC
OCR
PR
PX
Three-phase AC
power supply
≤
10 m
#
OFF ON
OCR
contact
Inverter
External
thermal
relay
,
$
GRZG type
discharging
resistor
Motor
#
To the brake unit
terminal P/+
To a resistor