Mitsubishi Electric FR-F820-00046 Instruction Manual page 257

 Acceleration time setting (Pr.607, Pr.608)
The electronic thermal O/L relay operation characteristic can be changed by setting the permissible load level according to the
motor characteristics.
 Electronic thermal O/L relay pre-alarm (TH) and warning signal (THP
signal)
• If the accumulated electronic thermal value reaches 85% of the Pr.9 or Pr.51 setting, electronic thermal O/L relay function
pre-alarm (TH) is displayed and the electronic thermal O/L relay pre-alarm (THP) signal is output. If the value reaches
100% of the Pr.9 setting, the motor thermal protection (E.THM/E.THT) is activated to shut off the inverter output. The
inverter output is not shut off with the TH display.
• For the terminal used for the THP signal output, assign the function by setting "8 (positive logic) or 108 (negative logic)" in
any of Pr.190 to Pr.196 (Output terminal function selection).
Electronic thermal
relay function
operation level
Electronic thermal O/L
(THP)
relay alarm
NOTE
• Changing the terminal assignment using Pr.190 to Pr.196 (Output terminal function selection) may affect the other
functions. Set parameters after confirming the function of each terminal.
 External thermal relay input (OH signal, E.OHT)
Thermal relay protector
Inverter
Motor
U
V
W
OH
SD
External thermal relay input connection diagram
• The External thermal relay input (OH) signal is used when using the external thermal relay or the thermal protector built
into the motor to protect the motor from overheating.
• When the thermal relay is activated, the inverter output is shut off by the external thermal relay (E.OHT).
• For the terminal used for the OH signal input, set "7" in any of Pr.178 to Pr.189 (Input terminal function selection) to
assign the function.
256
5. PARAMETERS
5.7 (H) Protective function parameter
Motor permissible
load 110%
240
180
120
60
0
80
(% to the inverter rated current)
Example of motor permissible load setting
(when Pr.9="100% of the inverter rating")
OFF ON
ON
M
Motor permissible
load 150% (Initial value)
Range for
the transistor
protection
100 120 140 160 180
Inverter output power (%)
100%
85%
Time
200