Mitsubishi Electric FR-F820-00046 Instruction Manual page 256

NOTE
• The internal accumulated heat value of the electronic thermal relay function is reset to the initial value by the inverter's power
reset or reset signal input. Avoid unnecessary reset and power-OFF.
• When using a PM motor other than MM-CF, set the free thermal parameters (Pr.600 to Pr.604) in accordance with the motor
characteristic.
• The transistor protection thermal O/L relay is activated early when the Pr.72 PWM frequency selection setting is increased.
 Set two types of electronic thermal O/L relays (Pr.51)
MC
MC
U
V
W
RT
SD
• These settings are used when rotating two motors with different rated current separately by a single inverter. (When
rotating two motors together, use an external thermal relay.)
• Set the rated motor current for the second motor in Pr.51 Second electronic thermal O/L relay.
• While the RT signal is ON, the setting values of Pr.51 is referred to provide thermal protection.
Pr.450 Pr.9
Second applied Electronic thermal
motor O/L relay
9999 0
9999 Other than 0
Other than 9999 0
Other than 9999 Other than 0
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.
IM
IM
Pr.51
Second electronic thermal
O/L relay
9999
0
0.01 to 500 (0.1 to 3600)
9999
0
0.01 to 500 (0.1 to 3600)
9999
0
0.01 to 500 (0.1 to 3600)
9999
0
0.01 to 500 (0.1 to 3600)
RT signal OFF
Second
First motor
monitor
× ×
× ×
× ∆
○ ×
○ ×
○ ∆
× ×
× ×
× ∆
○ ∆
○ ×
○ ∆
○: Values are accumulated by using the output current.
∆: Values are accumulated by assuming the output
current is "0 A" (cooling processing).
×: Electronic thermal O/L relay does not operate.
5.7 (H) Protective function parameter
RT signal ON
Second
First motor
monitor
× ×
× ×
× ○
○ ×
∆ ×
∆ ○
× ×
× ×
× ○
∆ ○
∆ ×
∆ ○
page 358.)
255
5. PARAMETERS
1
2
3
4
5
6
7
8
9
10