Danfoss VLT AQUA Drive FC 202 Programming Manual page 56

Parameter Description
3.4.2 2-1* Brake Energy Funct.
Parameter group for selecting dynamic braking parameters.
Only valid for frequency converters with brake chopper.
2-10 Brake Function
3 3
Option:
[0] Off
[1] Resistor
brake
[2] AC brake
2-11 Brake Resistor (ohm)
Range:
Size [ 5 -
related 65535
*
Ohm]
2-12 Brake Power Limit (kW)
Range:
Size [ 0.001 -
related 2000.000
*
kW]
54
Programming Guide
Function:
Available selections depend on
parameter 1-10 Motor Construction:
[0] Asynchron:
[0] Off
[1] Resistor brake
[2] AS brake
[1] PM non-salient:
[0] Off
[1] Resistor brake
No brake resistor installed.
Brake resistor incorporated in the system, for
dissipation of surplus brake energy as heat.
Connecting a brake resistor allows a higher DC-
link voltage during braking (generating operation).
The resistor brake function is only active in
frequency converters with an integral dynamic
brake.
AC Brake only works in Compressor Torque mode
in 1-03 Torque Characteristics.
Function:
Set the brake resistor value in Ω. This value
is used for monitoring the power to the
brake resistor in parameter 2-13 Brake Power
Monitoring. This parameter is only active in
frequency converters with an integral
dynamic brake.
Use this parameter for values without
decimals. For a selection with 2 decimals,
use parameter 30-81 Brake Resistor (ohm).
Function:
NOTICE
This parameter is only active in
frequency converters with an
integral dynamic brake.
Set the monitoring limit of the brake
power 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 formulas below.
Danfoss A/S © Rev. 2014-01-21 All rights reserved.
2-12 Brake Power Limit (kW)
Range: Function:
For 200-240 V units:
Presistor =
For 380-480 V units:
Presistor =
For 525-600 V units:
Presistor =
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.
[0] Off No brake power monitoring is required.
[1] Warning Activates a warning in the display when the
power transmitted over 120 s exceeds 100% of
the monitoring limit (parameter 2-12 Brake Power
Limit (kW)).
The warning disappears when the transmitted
power falls below 80% of the monitoring limit.
[2] Trip Trips the frequency converter and displays an
alarm when the calculated power exceeds 100%
of the monitoring limit.
[3] Warning Activates both of the above, including warning,
and trip trip and alarm.
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%).
2-15 Brake Check
Option: 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.
2
dutytime
390 ×
R × 120
2
dutytime
778 ×
R × 120
2
943 × dutytime
R × 120
MG20O702