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Motor starting current limits - IEC 60034-12

Motor starting current limits - IEC 60034-12

Motor starting current limits - IEC 60034-12

(OP)
good morning, I have the following problem with the selection of an electrical motor.
One of the customer requirements is that the figure Is/In (starting current, nominal current) has to be less than 6.5. My customer says that this is required to be in accordance with IEC 60034-12.

My supplier (well-known international motor manufacturer) offered a motor and this value is stated in the data-sheet, the figure is 7.3. But the datasheet also states that this value fulfill the requirements of the same IEC 60034-12.

My customer requires to review the motor selection because of this. The supplier states that the motor is already in accordance with IEC.

I do not have this regulation in my hand and cannot check what it says.

Could someone clarify to me what this regulation actually requires?

thank you very much.

RE: Motor starting current limits - IEC 60034-12

IEC 60034-12 Rotating electrical machines -Part 12:
Starting .performance of single-speed three-phase cage induction motors
states only the maximum Slocked/Prated ratio. Indeed,I(locked rotor)=Istarting at the
rated voltage[D.O.L.].
Let's say your motor is 100 kw 400V p.f.=0.9 efficiency=90% Irated=100/sqrt(3)/0.4/0.9/0.9=178.2 A
From Table 2 - Maximum values of locked rotor apparent power for design Nand H
for 63<Pn<630 kW S1=10.
That means Slocked[locked rotor=starting- apparent power] will be 10*100=1000 KVA. Istart=1000/sqrt(3)/0.4=1443.4 A
Istart/Irat=1443.4/178.2=8.1
From this standard, point of view both motors-one with 6.5 and other with 7.3-are suitable since both are less than 8.1.
However, if your customer requires 6.5 maximum he has the right to limit the starting current for his reason-breaker rating, voltage drop at start and other

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