Danfoss VLT AutomationDrive FC 300 Instruction Manual page 57

VLT ® AutomationDrive FC 300 Instruction
Manual
2-13 Brake Power Monitoring
Option:
[0] * Off
[1] Warning
[2] Trip
[3] Warning and trip
If power monitoring is set to Off [0] or
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%).
2-15 Brake Check
Option:
[0] * Off
[1] Warning
[2] Trip
[3] Stop and trip
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 (par. 2-11
duty time.
No braking energy monitoring required.
Activates a warning on the display when the power transmitted over 120 s exceeds 100% of the
monitoring limit (par. 2-12
The warning disappears when the transmitted power falls below 80% of the monitoring limit.
Trips 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.
Warning [1], the brake function remains active, even if the monitoring limit is exceeded. This may lead to thermal
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.
NOTE!
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%:
4. If the DC link ripple amplitude while braking is higher than the DC link ripple amplitude
before braking + 1%:
Monitors brake resistor and brake IGBT for a short-circuit during operation. If a short-circuit occurs,
warning 25 appears.
Monitors brake resistor and brake IGBT for a short-circuit, and runs a test for brake resistor dis-
connection 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 (e.g., warning 25, 27 or 28).
®
MG.33.AG.22 - VLT is a registered Danfoss trademark
Brake Resistor (ohm)
), the DC-link voltage, and the resistor
Brake Power Limit (kW) ).
Brake check has failed by returning a warning or alarm.
Brake check is OK.
4 How to Program
4
4-11