# Running a 3 phase 415V motor on 380V supply?



## Singh (Apr 17, 2017)

I have a Grundfos SP3A-45 which the supplier tells me is rated at 3 phase 415V. 

Im looking at a genset rated at 380V. I understand part of the confusion comes from EU 'harmonisation' and that modern equipment in the UK, which has a 415V supply is designed to also run at the EU 380V supply.

In the event that this pump isn't a 'harmonised' EU version designed to run at 380V, will it cause any problems with the pump?

Furthermore, the supplier is recommending a 7.5kW genset minimum for running the 3kW pump. Does that sound right?


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## aandpdan (Oct 8, 2012)

A lower voltage can cause the motor to overheat. It can also cause difficulty starting a heavy load.

Yes on the generator sizing. Startup demands can often exceed 2x the running load.


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## Osviur (Sep 7, 2015)

Hi Singh,

In the product description, it is clearly stated tha your pump can be supplied from 380 to 415 V 3 phase 50 Hertz :

•	Description
Product Description
Grundfos SP3A-45 3-phase 4″ submersible pump with 380-415V 50Hz, 3.00kW direct coupled 2900rpm electric motor.
ALL PUMPS ARE SUPPLIED WITH 2 YEAR WARRANTY.
Product number: 10101K45
We supply the whole range of GRUNDFOS borehole/well pumps. Please contact us for a price if you require a model that is not shown.

With respect to the generator size, Grundfos recommends, in accordance with the attached table
For a 3.7 KW pump, a 10 KW diesel generator for up to 150 M of elevation and a max of 100% of humidity.. For a 3 KW, as yours, interpolating, gives 8.5 KW

Hope to be helpful.

Regards.


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