Siemens COMBIMASTER Reference Manual page 31

Parameter
P064
External brake
stopping time
(seconds)
P065
Current threshold for
relay (A)
P066
P071 • • • •
Slip compensation (%)
P072 • • • •
Slip limit (%)
P073 • • • •
DC injection braking
(%)
30
Function Range
[Default]
0 - 20.0
[1.0]
0 - 99.9
[1.0]
0 - 200
[0]
0 - 500
[500]
0 - 150
[0]
COMBIMASTER & MICROMASTER Integrated
Description / Notes
As P063, only effective if the relay output is set to control an
external brake (P061 = 4) or the electro-mechanical brake
option is used (P062 = 4). This defines the period for which
the inverter continues to run at the minimum frequency after
ramping down and while the external brake is applied.
ON
t
P063
A
B
A = Brake applied
B = Brake removed
Settings for P063 and P064 should be slightly longer than
the actual time taken for the external brake to apply and
release respectively.
Setting P063 or P064 to too high a value, especially with
P012 set to a high value, can cause an overcurrent warning
or trip as the inverter attempts to move a locked motor shaft.
This parameter is used when P061 = 9. The relay switches
on when the motor current is greater than the value of P065
and switches off when the current falls to 90% of the value
of P065 (hysteresis).
Do not use!
The inverter can estimate the amount of slip in an
asynchronous motor at varying loads and increase its output
frequency to compensate. This parameter `fine tunes' the
compensation for different motors in the range
0 - 200% of the inverter's nominal estimate.
This limits the slip of the motor to prevent `pull-out' (stalling),
which can occur if slip is allowed to increase indefinitely.
When the slip limit is reached, the inverter reduces the
frequency until the level of slip is acceptable.
This stops the motor by applying a DC current. This causes
heat to be generated in the motor rather than the inverter
and holds the shaft stationary until the end of the braking
period. Braking is effective for the period of time set by
P003.
CAUTION: If a start signal is given during this time, the
motor will restart at the end of the braking period.
The DC brake can be activated using DIN1 - DIN3 (braking
is active for as long as the DIN is high - see P051 - P053).
Frequent use of long periods of dc injection braking can
cause the motor to overheat.
If DC injection braking is enabled via a digital input then DC
current is applied for as long as the digital input is high. This
causes heat in the motor.
Siemens plc. 1999
©
REFERENCE MANUAL
OFF
t
P064
A
| G85139-H1731-U300-D2