Mitsubishi Electric 800 Series Instruction Manual page 321

(H) Protective function parameter
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. The inverter output is not shut off with the warning signal (THP).
• For the terminal used for THP signal output, set "8 (positive logic)" or "108 (negative logic)" in any of Pr.190 to Pr.196
(Output terminal function selection) to assign the function.
Electronic thermal
relay function
operation level
Electronic thermal O/L
(THP)
relay alarm
OFF
• 100%: Electronic thermal O/L relay activation value
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
U
V
W
OH
SD
External thermal relay input connection diagram
• The external thermal relay input (OH) signal is used when using an external thermal relay or a thermal protector built into
the motor to protect the motor from overheating.
• When the thermal relay function is activated, the external thermal operation (E.OHT) shuts off the inverter output.
• 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.
• When the control terminal option (FR-A8TP) is used, valid/invalid setting of the terminal OH can be changed using Pr.876
Thermal protector input.
NOTE
• Changing the terminal assignment using Pr.178 to Pr.189 (Input terminal function selection) may affect the other
functions. Set parameters after confirming the function of each terminal.
320
PARAMETERS
100%
85%
ON
ON
Time
Motor
M