2-13 Brake Power Monitoring
Option:
Function:
NOTICE
This parameter is only active in
frequency converters with an integral
dynamic brake.
This parameter enables monitoring of the
power to the brake resistor. The power is
calculated on the basis of the resistance
(
parameter 2-11 Brake Resistor (ohm)
), the DC
link voltage, and the resistor duty time.
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%).
[0]
*
Off
No brake power monitoring is required.
[1]
Warning
120s
Activates a warning in the display when the
power transmitted over 120 s exceeds 100%
of the monitoring limit (
The warning disappears when the
transmitted power falls below 80% of the
monitoring limit.
[2]
Trip 120s
Trips the frequency converter and displays
an alarm when the calculated power exceeds
100% of the monitoring limit.
[3]
Warning &
trip 120s
Activates both of the above, 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
2-15 Brake Check
Option:
Function:
NOTICE
Remove a warning arising in connection
with
[0] Off
or
[1] Warning
by cycling the
mains supply. The fault must be corrected
first. For
[0] Off
or
[1] Warning
, the
frequency converter keeps running even if
a fault is located.
Select type of test and monitoring function to
check the connection to the brake resistor, or
whether a brake resistor is present, and then
display a warning or an alarm in the event of a
fault. The brake resistor disconnection 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.
Measure the DC link ripple amplitude
for 300 ms without braking.
2.
Measure the DC link ripple amplitude
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 b1%. If brake
check fails, a warning or alarm is
returned.
4.
If the DC link ripple amplitude while
braking is higher than the DC link ripple
amplitude before b1%. 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 runs a test for brake resistor
disconnection during power-up.
[2] Trip
Monitors for a short-circuit or disconnection of
the brake resistor, 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 resistor, 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.
[4] AC brake Monitors for a short-circuit or disconnection of
the brake resistor, or a short-circuit of the brake
IGBT. If a fault occurs, the frequency converter
performs a controlled ramp-down.
Parameter Descriptions
VLT
®
HVAC Drive FC 102
56
Danfoss A/S © 03/2015 All rights reserved.
MG11CE02
3
3
