Mitsubishi Electronics A800 ユーザーズマニュアル

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.

Connect the brake unit (FR-BU2) as shown below to improve the braking capability during deceleration.
After wiring securely, set Pr.30 Regenerative function selection = "11" .
Set Pr.0 Brake mode selection = "2" in the brake unit FR-BU2.

 • The stall prevention (overvoltage), oL, does not occur while Pr.30 Regenerative function selection = "11" .
 • For the parameter details, refer to the FR-A800 Instruction Manual (Detailed).



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, brake unit (FR-BU2) and resistor unit (MT-BR5) must be within 
5 m each. Even when the cable is twisted, the wiring 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.

P
PR

10 m or less

TH1

TH2

CR1

P
N

BUE
SD

P

PR

Brake unit

FR-BU2

Resistor unit

MT-BR5

TH1

TH2

Resistor unit

MT-BR5

P
PR

TH1

TH2

Resistor unit

MT-BR5

P
PR

MC

R/L1

Motor

M

Inverter/

converter

S/L2
T/L3

U
V

P/+

N/-

W

Three phase 
AC power 
supply

MCCB

MC

OFF

ON

MC

CR1

T

CR2

CR4

CR2 CR3 CR4

A
B
C

∗3

∗4

∗4

∗4

∗4

∗1

∗2

TH1

TH2

Resistor unit

MT-BR5

P
PR

CR3

∗5