Mitsubishi Electric FR-A800 Series Instruction Manual page 420

• While the RT signal is ON, the setting values of Pr.51 is referred to provide thermal protection.
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
• The RT signal is assigned to the terminal RT in the initial status. Set "3" in one of Pr.178 to Pr.189 (Input terminal function
selection) to assign the RT signal to another terminal.
 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.
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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")
search engine
RT signal OFF
Pr.51
First motor
O/L relay
×
×
×
○
○
○
×
×
×
○
○
○
○: 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.
Motor permissible
load 150% (Initial value)
Motor permissible
load 200%
Range for
the transistor
protection
80 100 120 140 160 180
Inverter output power (%)
(% to the inverter rated current)
RT signal ON
Second
First motor
monitor
× ×
× ×
Δ ×
× ○
× Δ
Δ Δ
× ×
× ×
Δ ×
Δ Δ
× Δ
Δ Δ
200
5. PARAMETERS
5.10 (H) Protective function parameter
1
Second
monitor
×
2
×
○
×
3
×
○
×
×
4
○
○
×
5
○
6
page 525.)
7
8
9
10
419