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17
Function library
17.1
Function blocks | L_MFail_1
1415
Lenze · 8400 HighLine · Reference manual · DMS 12.0 EN · 06/2017 · TD23
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17.1.102.7 Reset mains failure control
The mains failure control is rest by setting
bReset
to TRUE.
• A reset via
bReset
is always required when the restart protection is active or the restart
protection is used and the supply (mains or DC supply) has been switched on.
• The
bReset
input can, for instance, be connected to a digital input.
17.1.102.8 Restart protection
The integrated restart protection is to prevent a restart in the lower speed range when the supply
voltage was only interrupted briefly (mains recovery before drive stands still).
• The
nThreshold_a
input serves to specify the restart threshold in [%] with regard to the
) below which no start has to take place after mains recovery.
• If in case of mains recovery the speed is below the restart threshold, the drive is continued to
be braked in a controlled way. This function is only stopped by setting
bReset
to TRUE.
• If the speed is above the restart threshold after mains recovery, the drive changes to its
setpoint
nNSet_a
.
• The function is switched inactive when
nThreshold_a
= 0 %.
• A reset takes place by setting
bReset
to TRUE and is required after every mains switching.
• In this case, the
bActive
output is set to TRUE when the
bFault
input is set to FALSE.
17.1.102.9 Quick mains recovery (KU)
The quick mains recovery causes a restart of the inverter if the restart protection is not active
anymore.
• In case, the drive reaches its setpoint.
• If this behaviour is not desired, you can delay the restart by setting a retrigger time in
or prevent it by using the restart protection.
• Dependent on the system, the mains recovery is reported through the mains failure control via
the level of the DC-bus voltage.
Procedure of the mains failure control
A quick mains recovery is caused by a "quick interruption" of the energy supply company (e.g.
thunderstorm) and by faulty components in the supply cables (e.g. collector rings).
• Then, set the retrigger time in
higher than the measured deceleration time reached
in braking operation.