Mitsubishi Electric FR-E800 Series Instruction Manual page 243

• While the RT signal is ON, the setting values of Pr.51 is referred to provide thermal protection. (While the RT signal is ON,
the setting values of Pr.9 is referred to provide thermal protection under PM sensorless vector control.)
Pr.450
Second applied
motor
9999
9999
Other than 9999
Other than 9999
NOTE
• The RT signal is the Second function selection signal. The RT signal also enables other second functions. (Refer to
• For the RT signal, set "3" in any parameter from Pr.178 to Pr.189 (Input terminal function selection) to assign the function.
 Motor permissible load level (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.
*1 Depending on the settings of Pr.607 and Pr.608, this thermal protection may not be provided as set, as an inverter overload trip (electronic thermal
relay function) (E.THT) may be activated before the thermal protection.
 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.
242
11. (H) Protective Function Parameters
11.1 Motor overheat protection (electronic thermal O/L relay)
Pr.9
Electronic thermal Second electronic thermal
O/L relay
9999
0 0
0.01 to 500 (0.1 to 3600)
9999
Other than 0 0
0.01 to 500 (0.1 to 3600)
9999
0 0
0.01 to 500 (0.1 to 3600)
9999
Other than 0 0
0.01 to 500 (0.1 to 3600)
Motor permissible
load 110%
240
180
120
60
0
Example of motor permissible load setting
(when Pr.9="100% of the inverter rating")
RT signal OFF
Pr.51
First motor
O/L relay
×
×
×
○
○
○
×
×
×
○
○
○
Motor permissible
load 150% (Initial value)
Motor permissible
load 200%
Range for
the transistor
protection *1
80 100 120 140 160 180
Inverter output power (%)
(% to the inverter rated current)
Second
First motor
monitor
× ×
× ×
Δ ×
× ○
× Δ
Δ Δ
× ×
× ×
Δ ×
Δ Δ
× Δ
Δ Δ
○: Values are accumulated by using the output current.
Δ: Values are accumulated by assuming the output
current is 0 A (cooling processing).
×: Electronic thermal O/L relay does not operate.
200
RT signal ON
Second
monitor
×
×
○
×
×
○
×
×
○
○
×
○
page 334.)