Mitsubishi Electric FR-A820-04750-GF Instruction Manual page 101

FR-A800/A800 Plus Series
Instruction Manual Supplement
1
Earth (ground) fault detection at start / restricting reset
method for an earth (ground) fault
The reset method for the output side earth (ground) fault overcurrent (E.GF) can be restricted.
• Select whether to enable or disable the earth (ground) fault detection at start. When enabled, the earth (ground)
fault detection is performed immediately after a start signal input to the inverter.
• Select whether to restrict the reset method for an earth (ground) fault.
Pr.
249 Earth (ground) fault detection
H101 at start
 Selecting whether to perform the earth (ground) fault detection at
start
V/F V/F V/F Magnetic flux Magnetic flux Magnetic flux
• If an earth (ground) fault is detected at start while Pr.249 = "1 or 2", the output side earth (ground) fault overcurrent
(E.GF) is detected and output is shut off.
• Earth (ground) fault detection at start is enabled under V/F control and Advanced magnetic flux vector control.
• When the Pr.72 PWM frequency selection setting is high, enable the earth (ground) fault detection at start.
NOTE
• Because the detection is performed at start, output is delayed for approx. 20 ms every start.
• Use Pr.249 to enable/disable the earth (ground) fault detection at start. During operation, earth (ground) faults are
detected regardless of the Pr.249 setting.
 Restricting reset method for an earth (ground) fault
• The reset method when the output is shut off due to the output side earth (ground) fault overcurrent (E.GF) can
be restricted. When E.GF occurs while Pr.249 = "2", E.GF can be reset only by turning OFF the control circuit
power.
• This restriction prevents the inverter from being damaged due to repeated reset operations by the other methods
such as entering the RES signal.
• When E.GF occurs while Pr.249 = "2", the output short-circuit detection (ALM4) signal can be output.
• For the terminal used to output the ALM4 signal, set "23" (positive logic) or "123" (negative logic) in any of Pr.190
to Pr.196 (Output terminal function selection).
• If Pr.249 is set to "2" while the retry function is enabled (Pr.67 is not set to "0"), no retry is performed even when
E.GF occurs.
• If Pr.249 is set to "2" while the automatic bypass switching after inverter fault is enabled (Pr.138 is not set to "1"),
the operation is not switched to the commercial power supply operation even when E.GF occurs.
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.
• E.GF is not cleared by turning ON the Fault clear (X51) signal when Pr.249 = "2".
• If E.GF occurs during emergency drive operation when Pr.249 = "2", the output is shut off.
Name Initial value
0
Setting range
Earth (ground) fault
0 Not detected at start
1
Detected at start
2
1
Description
Reset method
Not restricted
Restricted
BCN-C22005-991