GE Ecomagination AF-600 FP Programming Manual page 196

Parameter Description
3.26.2 B-1# Brake Energy Funct.
Parameter group for selecting dynamic brake parameters.
B-10 Brake Function
Option: Function:
Available options depend on
parameter P-20 Motor Construction:
[0] Asynchron:
•
[0] Off
•
[2] AC brake
[1] PM non-salient:
•
[0] Off
[0] Off No brake resistor installed.
*
[1] Resistor Brake resistor incorporated in the system for
brake dissipation of excess 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.
[2] AC brake AC brake only works in compressor torque mode
in parameter H-43 Torque Characteristics.
B-11 Brake Resistor (ohm)
Range: Function:
Set the brake resistor value in Ω. This value
50.00 [5.00 -
Ohm 65535.00 is used for monitoring the power to the
*
Ohm] brake resistor in parameter B-13 Braking
Thermal Overload. 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 B-11 Brake Resistor (ohm).
B-12 Brake Power Limit (kW)
Range: Function:
5.000 [0.001 - Parameter B-12 Brake Power Limit (kW) is the
kW 2000.000 expected average power dissipated in the
*
kW] brake resistor over a period of 120 s. It is
used as the monitoring limit for
parameter DR-33 Brake Energy Average and
thereby specifies when a warning/alarm is
to be given.
To calculate parameter B-12 Brake Power
Limit (kW), the following formula can be
used.
P W =
br, avg
P is the average power dissipated in
br,avg
the brake resistor, R
the brake resistor. t
time within the 120 s period, T
DET-620D
AF-600 FP™ Programming Guide
2
U V × t s
br br
R Ω × T s
br br
is the resistance of
br
is the active breaking
br
.
br
03/2016 All rights reserved.
B-12 Brake Power Limit (kW)
Range: Function:
U is the DC voltage where the brake
br
resistor is active. This depends on the unit
as follows:
200–240 V: 390 V
380–500 V: 810 V
525–600 V: 943 V
525–690 V: 1099 V
NOTICE
If R is not known, or if T
br
different from 120 s, the practical
approach is to run the brake
application, readout
parameter DR-33 Brake Energy Average
and then enter this
+ 20% in parameter B-12 Brake Power
Limit (kW).
B-13 Braking Thermal Overload
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
based on the resistance (parameter B-11 Brake
Resistor (ohm)), the DC-link voltage, and the
resistor duty time.
[0] Off No brake power monitoring is required.
*
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%).
[1] Warning Activates a warning when the power transmitted
over 120 s exceeds 100% of the monitoring limit
(parameter B-12 Brake Power Limit (kW)).
The warning disappears when the transmitted
power drops below 80% of the monitoring limit.
[2] Trip Trips the frequency converter and shows 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.
[4] Warning
30s
3 3
is
br
195