Connection Of Stand-Alone Option Units - Mitsubishi Electric 800 Series Instruction Manual

2.10

Connection of stand-alone option units

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.
2.10.1
Connection of the brake resistor other than the
provided brake resistor
When an inverter-driven motor is driven by a load or requires rapid deceleration, install a brake resistor. A brake resistor is
provided with the FR-A860-00090 or lower. Fit another brake resistor when the provided brake resistor does not have enough
thermal capability for high-duty operation. For the FR-A860-00027 to 00170, and the FR-A860-00450 to 01080, connect the
brake resistor across terminals P3 and PR. For the FR-A860-00320, connect the brake resistor across terminals P/+ and PR.
(For the locations of terminal P3(P/+) and PR, refer to the terminal block layout
The brake resistor should be as listed in the following table. Selected the rated power of the brake resistor according to the
brake duty. (The rated power indicated below assumes that the brake resistor duty is 10%)
Inverter size
FR-A860-00027
FR-A860-00061
FR-A860-00090
FR-A860-00170
FR-A860-00320
FR-A860-00450
FR-A860-00680
FR-A860-01080

For the FR-A860-00320 or higher, the brake duty is 6%.
Set parameters as below.
• Pr.30 Regenerative function selection = "1"
• Pr.70 Special regenerative brake duty = "FR-A860-00170 or lower: 10%, FR-A860-00320 or higher: 6%"
(Refer to page 608.)
• When the regenerative brake transistor is damaged, install a thermal relay as shown in the following sequence diagrams to
prevent overheat and burnout of the brake resistor. Properly select a thermal relay according to the regenerative driving
frequency or the rated power or resistance of the brake resistor.
<Example 1>
Inverter
MC
R/L1
Power
S/L2
Supply
T/L3
T
F
MC
OFF ON
OCR
Contact
MC
NOTE
• The brake resistor cannot be used together with a brake unit.
• Do not connect the provided brake resistor when connecting the brake resistor other than the provided brake resistor across
terminals P3(P/+) and PR. Otherwise the inverter may be damaged.
CAUTION
 If the resistor selection is incorrect, overcurrent may damage the inverter built-in brake transistor.
Also, the resistor may be burned due to overheat.
 If the selection of the thermal relay is incorrect, the resistor may be burned due to overheat.
Brake resistance
1000  or more
370  or more
220  or more
110  or more
60  or more
40  or more
24  or more
16  or more
Thermal
relay
(OCR)
Brake resistor
P3
R
(P/+)
PR
Connection of stand-alone option units
(page 35).)
Reference rated power at brake duty of 10% (6%)
180 W or more
500 W or more
800 W or more
1600 W or more
3600 W or more
5500 W or more
9000 W or more
13500 W or more
<Example 2>
MC Inverter
R/L1
Power
(P/+)
S/L2
Supply
T/L3
T
F
B
MC
OFF ON
C
OCR
Contact
MC
INSTALLATION AND WIRING

Thermal
relay
(OCR) Brake resistor
P3
R
PR
2
65