Mitsubishi Electric FR-A820-00046 Instruction Manual page 114

Connection of stand-alone option units
Connection example with the MT-BR5 type resistor unit
After wiring securely, set Pr. 30 "Regenerative function selection"= "1" and Pr. 70 "Special regenerative
brake duty" = "0 (initial value)".
Set Pr. 0 "Brake mode selection" = "2" in the brake unit FR-BU2.
Fig. 2-61:
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.
The wiring distance between the inverter and brake unit (FR-BU2), and between the brake unit
(FR-BU2) and resistor unit (MT-BR5) must be within 5 m each. Even when the wire is twisted, the
cable length must be within 10 m.
The contact between TH1 and TH2 is open in the normal status and is closed at a fault.
The CN8 connector used with the MT-BU5 type brake unit is not used.
NOTE The stall prevention (overvoltage), oL, does not occur while Pr. 30 "Regenerative function selec-
tion" = "1" and Pr. 70 "Special regenerative brake duty" = "0% (initial value)." (Refer to page 5-675.)
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MCCB
Three-phase AC
power supply
Connection example with the MT-BR5 type resistor unit
*2
T
MC
Motor
R/L1 U
V
S/L2
M
T/L3 W
P/+
P
N/- N
BUE
SD
Inverter
Brake unit
FR-BU2
Installation and wiring
ON OFF
CR1
MC
MC
≤ 10m
CR1
P TH1
P
PR
PR
TH2
Resistor unit
MT-BR5
I002410E