Siemens SINUMERIK 840C Installation Instructions Manual page 469

7 Drive Machine Data (SIMODRIVE Drive MD)
7.2.2 FDD MD (data description - SW 3)
1108
Default value
200
Input of maximum thermally permissible current of power section. The input is an RMS value.
This machine data is automatically parameterized for Siemens power sections by the machine
data "Power section code" (MD 1106).
1110
Reduction factor max. motor current set-up mode
Default value
1
Input of reduction factor for set-up mode. The transistor limit current (MD 1107) acts as the
reference value. Please note that if the current limit calculated for set-up mode exceeds the
maximum unit-specific current value, then it will be reduced to this value. The maximum
permissible unit-specific current is calculated as a minimum value from MD 1104 (maximum
motor current) x 2 x MD 1105 (reduction max. motor current), maximum current of power
section (e.g. 9/18A 100% corresponds to 18 A
current) x 2.
Example:
Max. motor current
Reduction max. motor current
Transistor limit current
Power section limit current
Unit-specific max. permissible current (normal mode) = min. (100 % x 5 A; 25 A; 18 A x 2)
Unit-specific max. permissible current (normal mode) = 5 A
Example 1: Reduction factor max. motor current set-up mode (MD 1110) = 50 %
Unit-specific permissible current (set-up mode) = min. (5 A; 25 A x 0.5)
Unit-specific permissible current (set-up mode) = 5 A
Example 2: Reduction factor max. motor current set-up mode (MD 1110) = 10 %
Unit-specific permissible current (set-up mode) = min. (5 A; 25 A x 0.1)
Unit-specific permissible current (set-up mode) = 2.5 A
1112
Default value
3
Input of number of pole pairs of motor as specified on the motor data sheet (non-Siemens
motor) or through automatic parameterization using machine data "Motor code number"
(MD 1102). The numbers of pole pairs encountered in practice are 2, 3 and 4. The pole pair
number 0 is entered when motor/power section combinations which have not been enabled are
loaded.
7–54
Limit current power section
Lower input limit Upper input limit
1
Lower input limit Upper input limit
0
) and MD 1108 (power section limit
RMS
(MD 1104) =
(MD 1105) =
(MD 1107) =
(MD 1108)
Number of pole pairs motor
Lower input limit Upper input limit
0
©
Siemens AG 1992 All Rights Reserved
Units
500
Units
100 %
5 A
100 %
25 A
18 A
Units
4
6FC5197- AA50
SINUMERIK 840C (IA)
12.93
Active on
Power On
A
Active on
Power On
Active on
Power On
–