Danfoss VLT AutomationDrive FC 301 Programming Manual page 83

Parameter Descriptions
2-13 Brake Power Monitoring
Option: Function:
This parameter is only active in
frequency converters with a brake.
This parameter enables monitoring
of the power to the brake resistor.
The power is calculated based on
the resistance (parameter 2-11 Brake
Resistor (ohm)), the DC-link voltage,
and the resistor duty time.
[0] Off No brake power monitoring
*
required.
[1] Warning 120s Activates a warning on the display
when the power transmitted during
the duty time exceeds 100% of the
monitoring limit
(parameter 2-12 Brake Power Limit
(kW).
The warning disappears when the
transmitted power drops below
80% of the monitoring limit.
[2] Trip 120s Trips the frequency converter and
shows an alarm when the
calculated power exceeds 100% of
the monitoring limit.
[3] Warning & trip Activates both of the above,
120s including warning, trip, and alarm.
[4] Warning 30s
[5] Trip 30s
[6] Warning & trip
30s
[7] Warning 60s
[8] Trip 60s
[9] Warning & trip
60s
[10] Warning 300s
[11] Trip 300s
[12] Warning & trip
300s
[13] Warning 600s
[14] Trip 600s
[15] Warning & trip
600s
If power monitoring is set to [0] Off or [1] Warning, the
brake function remains active, even if the monitoring limit
is exceeded. This may lead to thermal overload of the
resistor. It is also possible to generate a warning via a
relay/digital output. The measuring accuracy of the power
monitoring depends on the accuracy of the resistance of
the resistor (better than ±20%).
M0013101
Programming Guide
2-15 Brake Check
Option:
[0]
*
[1]
[2]
Danfoss A/S © 10/2019 All rights reserved.
Function:
Parameter 2-15 Brake Check is only
active in frequency converters with
an integral dynamic brake.
Select type of test and monitoring
function to check the connection to
the brake resistor, or whether a
brake resistor is present, and then
show a warning or an alarm in the
event of a fault.
NOTICE
The brake resistor discon-
nection function is tested
during power-up. However, the
brake IGBT test is performed
when there is no braking. A
warning or trip disconnects
the brake function.
The testing sequence is as follows:
1. The DC-link ripple
amplitude is measured for
300 ms without braking.
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
braking + 1%: Brake check
has failed by returning a
warning or alarm.
4. If the DC-link ripple
amplitude while braking is
higher than the DC-link
ripple amplitude before
braking + 1%: Brake check
is OK.
Off Monitors brake resistor and brake
IGBT for a short circuit during
operation. If a short circuit occurs,
Warning 25 Brake resistor short-
circuited appears.
Warning Monitors brake resistor and brake
IGBT for a short circuit and runs a
test for brake resistor disconnection
during power-up.
Trip Monitors for a short circuit or
disconnection of the brake resistor,
or a short circuit of the brake IGBT.
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