Mitsubishi Electric FR-A500 Instruction Manual page 38

(2) Connection of the brake unit (FR-BU)
Connect the optional FR-BU brake unit as shown below to improve the braking capability during deceleration.
MC
Power
supply
Remove jumper.
Note: 1. Connect the inverter terminals (P, N) <+, -> and FR-BU brake unit terminals so that their terminal
signals match with each other. (Incorrect connection will damage the inverter.) For model 7.5K or
less, the jumper across terminals PR-PX must be removed.
2. The wiring distance between the inverter, brake unit and resistor unit should be within 5m (16.40
feet). If twisted wires are used, the distance should be within 10m (32.81 feet).
3. When the transistor in the brake unit fails, the brake transistor becomes extremely hot and it has
a chance to get fire. Therefore, install a magnetic contactor on the inverter's power supply side to
shut off a current in case of failure.
4. When the power supply is 400V class, install a step-down transformer.
T (Note 4)
< >
Motor
R L U
1
< >
S L V
IM
2
< >
T L W
3
Inverter
PR P/+ P/+
PX N/– N/-
Brake unit
FR-BU-(H)
29
INSTALLATION AND WIRING
ON
OFF
MC
PR P
PR
HA
HB
TH1
HC
THS TH2
Resistor unit
FR-BR-(H)
MC
Normal : TH1 - TH2....close
Alarm : TH1 - TH2....open
2