Danfoss VLT AQUA Drive FC 200 Programming Manual page 56

Parameter Description
2-12 Brake Power Limit (kW)
Range:
Size [ 0.001 -
3 3
related 2000.000
*
kW]
NOTICE!
This parameter is only active in adjustable frequency drives
with an integral dynamic brake.
2-13 Brake Power Monitoring
Option:
[0] Off
[1] Warning
[2] Trip
[3] Warning
and trip
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%).
3-30
VLT
Function:
Set the monitoring limit of the braking
energy transmitted to the resistor.
The monitoring limit is a product of the
maximum duty cycle (120 s) and the
maximum power of the brake resistor at
that duty cycle. See the formula below.
For 200–240 V units:
2
390 × dutytime
P resistor =
R × 120
For 380–480 V units:
2
778 × dutytime
P resistor =
R × 120
For 525–600 V units:
2
943 × dutytime
P resistor =
R × 120
Function:
This parameter is only active in adjustable
frequency drives 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 (2-11 Brake Resistor
(ohm), the DC link voltage, and the resistor duty
time.
No braking energy monitoring is required.
Activates a warning on the display when the
power transmitted over 120 s exceeds 100% of
the monitoring limit (2-12 Brake Power Limit
(kW)).
The warning disappears when the transmitted
power falls below 80% of the monitoring limit.
Trips the adjustable frequency drive and displays
an alarm when the calculated power exceeds
100% of the monitoring limit.
Activates both of the above, including warning,
trip and alarm.
MG20O622 - VLT
®
AQUA Drive Programming Guide
2-15 Brake Check
Option:
[0] Off
[1] Warning
[2] Trip
[3] Stop and
trip
[4] AC brake
NOTICE!
Remove a warning arising in connection with [0] Off or [1]
Warning by cycling the line power supply. The fault must
be corrected first. For [0] Off or [1] Warning, the adjustable
frequency drive keeps running even if a fault is located.
®
is a registered Danfoss trademark
Function:
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. 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 failed, return 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 OK.
Monitors brake resistor and brake IGBT for a
short-circuit during operation. If a short-circuit
occurs, a warning appears.
Monitors brake resistor and brake IGBT for a
short-circuit, and to run a test for brake resistor
disconnection during power-up.
Monitors for a short-circuit or disconnection of
the brake resistor, or a short-circuit of the brake
IGBT. If a fault occurs, the adjustable frequency
drive cuts out while displaying an alarm (trip
locked).
Monitors for a short-circuit or disconnection of
the brake resistor, or a short-circuit of the brake
IGBT. If a fault occurs, the adjustable frequency
drive ramps down to coast and then trips. A trip
lock alarm is displayed.