Connection Of The Brake Resistor; Connection Of The Dc Reactor - Mitsubishi Electric 800 Series Instruction Manual

Incorrect connection will cause inverter damage or accident. Connect and operate the option unit carefully in accordance with
the Instruction Manual of the corresponding option unit.
2.8.1

Connection of the brake resistor

• When an inverter-driven motor is driven by a load or requires rapid deceleration, install an external brake resistor. Connect
the brake resistor to terminals P/+ and PR. (For the locations of terminals P/+ and PR, refer to the terminal block layout
(page 39).)
Use a brake resistor that has resistance and power consumption values higher than the following. Also, the brake resistor must
have a sufficient capacity to consume the regenerative power.
Voltage
Inverter
class
FR-E860-0017(0.75K)
FR-E860-0027(1.5K)
FR-E860-0040(2.2K)
575 V class
FR-E860-0061(3.7K)
FR-E860-0090(5.5K)
FR-E860-0120(7.5K)
Set parameters as follows:
• Pr.30 Regenerative function selection = "1"
• Set Pr.70 Special regenerative brake duty according to the amount and frequency of the regenerative driving, and make
sure that the resistor can consume the regenerative power properly. (Refer to the FR-E800 Instruction Manual (Function).)
• When the regenerative brake transistor is damaged, install a thermal relay as shown in the following sequence 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
ON OFF
OCR
Contact
MC
CAUTION
• If the resistor selection is incorrect, overcurrent may damage the inverter built-in brake transistor. Besides, 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.
2.8.2

Connection of the DC reactor

• When using the DC reactor, connect it to terminals P/+ and P1.
In this case, the jumper connected across terminals P/+ and P1 must be removed. Otherwise, the reactor will not be
effective.
• Select a DC reactor according to the applied motor capacity. (Refer to
Minimum resistance Power consumption
(Ω)
350 2.4
300 2.8
260 3.3
190 4.5
140 6.1
100 8.5
Thermal relay
(OCR)
Brake resistor
P/+ R
PR
P1
Remove
the jumper
(kW)
<Example 2>
MC Inverter
R/L1
Power
S/L2
Supply
T/L3
T
F
B
MC
ON OFF
C
OCR
Contact
MC
P/+
DC reactor
page 84.)
2.8 Connection of stand-alone option units
Thermal relay
(OCR) Brake resistor
P/+
R
PR
2. Installation and Wiring
1
2
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5
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9
10
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