SIMOVERT P 6SE21 Series Inverters
English
Operating Instructions
Siemens plc 1995
G85139–A1615–U156–A
02.95
25
Parameter
Number
Description
Display
Setting
(Default)
Notes
P15
Voltage to frequency relationship:
‘knee point’ (Hz)
00.1 –
400
(50.0)
[60.0]
Sets the knee frequency on a user–defined curve. Used when P06 is
set to 006.
P16
Voltage to frequency relationship:
curve type
000
001
(000)
Linear from 0 Hz to knee frequency when P06 is set to 006.
Voltage proportional to (frequency)
1.5
when P06 is set to 006.
P17
•
Current limit (A)
00.1 –
inverter
rated
output in
Amperes
(1.1 x
inverter
rating)
This parameter sets the current limit of the inverter in amperes. This
current limit operates after 60 s (P18 sets the overload limit) by
reducing the output frequency until the output current falls below the set
value. The display flashes when the current set by P17 is exceeded or
when the current limit is active.
P18
•
Overload limit
01.0 –
03.0
(01.5)
This parameter sets the overload limit used during automatic boost and
overload current limit operation. The current limit (set in P17) may be
exceeded for up to 60 s, providing the current does not exceed P17 x
P18. If this occurs, or in any case after 60 s, the output frequency is
reduced until the current falls below the value of P17.
The overload limit is also used during automatic boost operation.
P19
Automatic boost
000 –
003
000
001
002
003
(000)
Automatic Boost Operation
Automatic boost is enabled when P19 is set to 001 or 003. For correct
operation, set P17 to the nominal motor current as stated on the rating
plate. The next time the inverter is run after P19 has been set to 001 or
003, the inverter measures the motor resistance and uses this value to
calculate the required boost. This value is written to parameter P01,
where it may be read but not changed. During the calculation period
(lasts a few seconds), ‘CAL’ is indicated on the display. The inverter
then starts and runs normally.
The inverter can provide additional boost during ramp–up by setting
P19 to 002 or 003. In these cases boost operates as normal (i.e.
manually or automatically derived) when the inverter is running, but
during ramp–up the boost percentage is increased by the factor P18 to
provide additional torque during ramp–up. The boost reverts to that
defined by P01 when the setpoint is reached.
Manual boost setting, no additional boost.
Automatic boost setting, no additional boost.
Manual boost setting, additional boost on ramp–up.
Automatic boost setting, additional boost on ramp–up.
