5 Appendix
5.5 Adjustment factors for utilization categories
58
Elektronischer Motorstarter EMS/Electronic Motor Starter EMS
04/15 MN03407009Z-DE/EN
www.eaton.com
5.5 Adjustment factors for utilization categories
The following adjustment factors refer to EMS electronic motor starters with
a maximum load current of 9 A. By using the load current, the overcurrent
factor (see the data sheet for the relevant motor), and the 9-A derating curve,
you can calculate the motor‘s maximum permissible rated operational current.
Overcurrent factor I
A
/I
N
1
1)
2
3
4
5
6
7
8
2)
9
10
Adjustment factor K
1
1
1
1
1
0.96
0.83
0.72
0.64
0.58
1) Utilization category AC-51
2) Utilization category AC-53a
Example 1
Example 2
Motor with overcurrent factor
(from motor data sheet)
I
A
/I
N
= 8
Motor with overcurrent factor
(from motor data sheet)
I
A
/I
N
= 5
Adjustment factor
(from table above)
K = 0.72
Adjustment factor
(from table above)
K = 1
Maximum permissible load current at
40 °C, not connected in series
(from derating curve, EMS…-24VDC)
I
N
= 9 A
Maximum permissible load current at
60 °C, not connected in series
(from derating curve, EMS…-24VDC)
I
N
= 4.0 A
The motor starter‘s maximum
permissible rated operational current
I
N
= 6.5 A
The motor starter‘s maximum
permissible rated operational current
I
N
= 4.0 A
