Eaton EMS Series - Adjustment Factors for Utilization Categories

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