2.
The DC link ripple amplitude is measured for 300 ms
with the brake turned on.
3.
If the DC link ripple amplitude while braking is lower
than the DC link ripple amplitude before b 1
%. Brake check failed, return a warning or alarm.
4.
If the DC link ripple amplitude while braking is higher
than the DC link ripple amplitude before b 1
%. Brake check OK.
[0]
*
Off
Monitors brake resistor and brake IGBT for a short-circuit during
operation. If a short-circuit occurs, a warning appears.
[1]
Warning
Monitors brake resistor and brake IGBT for a short-circuit, and
to run a test for brake resistor disconnection during power-up
[2]
Trip
Monitors for a short-circuit or disconnection of the brake resis-
tor, or a short-circuit of the brake IGBT. If a fault occurs the
frequency converter cuts out while displaying an alarm (trip
locked).
[3]
Stop and Trip
Monitors for a short-circuit or disconnection of the brake resis-
tor, or a short-circuit of the brake IGBT. If a fault occurs the
frequency converter ramps down to coast and then trips. A trip
lock alarm is displayed.
NB!
NB!: Remove a warning arising in connection with
Off
[0] or
Warning
[1] by cycling
the mains supply. The fault must be corrected first. For
Off
[0] or
Warning
[1], the
frequency converter keeps running even if a fault is located.
2-17 Over-voltage Control
Option:
Function:
Over-voltage control (OVC) reduces the risk of the frequency
converter tripping due to an over voltage on the DC link caused
by generative power from the load.
[0]
Disabled
No OVC required.
[2]
*
Enabled
Activates OVC.
NB!
The ramp time is automatically adjusted to avoid tripping of the frequency converter.
2. Parameter Description
VLT
®
AQUA Drive Programming Guide
60
MG.20.O2.02 - VLT
®
is a registered Danfoss trademark
2