Mitsubishi FR-A740-00023-EC, Instruction Manual

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Connection of stand-alone option units
2.5.2 Connection of the brake unit (FR-BU2)
Connect the brake unit (FR-BU2) as shown below to improve the braking capability at deceleration.
(1) Connection example with the GRZG type brake resitor
<Recommended external thermal relay>
*1 Connect the inverter terminals (P/+, N/-) and brake unit (FR-BU2) terminals so that their terminal names match with each other.
(Incorrect connection will damage the inverter and brake unit.)
*2 When the power supply is 400V class, install a step-down transformer.
*3 Be sure to remove a jumper across terminal PR-PX when using the FR-BU2 with the inverter of 00250 or less.
*4 Keep a wiring distance of within 5m between the inverter, brake unit (FR-BU2) and brake resistor. Even when the wiring is
twisted, the cable length must not exceed 10m.
*5 It is recommended to install an external thermal relay to prevent overheat of brake resistors.
Brake Unit Brake Resistor Recommended External Thermal Relay
FR-BU2-1.5K GZG 300W-50
Ω
TH-N20CXHZ 1.3A
FR-BU2-3.7K GRZG 200-10
Ω
TH-N20CXHZ 3.6A
FR-BU2-7.5K GRZG 300-5
Ω
TH-N20CXHZ 6.6A
FR-BU2-15K GRZG 400-2
Ω
TH-N20CXHZ 11A
FR-BU2-H7.5K GRZG 200-10
Ω
TH-N20CXHZ 3.6A
FR-BU2-H15K GRZG 300-5
Ω
TH-N20CXHZ 6.6A
FR-BU2-H30K GRZG 400-2
Ω
TH-N20CXHZ 11A
CAUTION
⋅
To replace the existing BU type brake unit, set "1" in Pr. 0 Brake mode selection of the FR-BU2.
⋅
Do not remove a jumper across terminal P/+ and P1 except when connecting a DC reactor.
U
V
W
P/+
N/-
R/L1
S/L2
T/L3
Motor
IM
Inverter
PR
N/-
BUE
SD
P/+
A
B
C
FR-BU2
GRZG type
brake resistor
R R
Three-phase AC
power supply
MCCB
MC
OFF ON
MC
T
PR
PX
*1
5m (16.4feet) or less
*4
*4
*3
*2
MC