Will 400 V three Phase system work with a supply of 380V three Phase

Anonymous user · ‎2020-08-29

We have a juice Production line working with a rating voltage of 400 V three phase. it is planned to be moved to another country having a voltage rating of 380 V three phase.

will it work there efficiently? or it needs modifications.

Thanks

Mohammad Obaidat

MathieuGuillot · ‎2020-09-02

Hello,

I don’t see any risk of major malfunction during operation at 380Vac nominal voltage for a system designed for 400Vac. Indeed large majority of equipment designed for 400Vac are applicable to 380Vac. But as we say “The Devil is in the Details.”

To ensure proper functioning of the future installation you should check few things:

I suggest to start your analysis by checking the tolerances of the supply voltage in both locations. What is the minimum voltage you may have today and what is the minimum voltage you may have tomorrow. If the tolerance of the supply in your new location is -10% you have to check that your production line can withstand temporary operation at 340Vac LL 200Vac LN. But may be your existing system is 400Vac -10% and the future 380Vac – 5% …
When you know the minimum voltage you can reach in the future, global efficiency and performance will depend on the type of loads.
- Some loads have a current proportional to the voltage (Typically resistor like heaters ..) for this loads the voltage reduction will means current reduction. From process point of view it will means longer operation for an heater to reach the same temperature.
- Some loads have a constant power, so voltage reduction means current increase. (Typically electronic converters such as variable speed drive, electronic power supply …) In that case there is no consequence on the process itself, but the supply and electrical equipment (cables, circuit-breaker, contactors…) upstream such loads need to handle the increase of the current. (Risk is overload trip for instance)
- Some loads have a more complex relationship between voltage and current : typically induction motors. Reduction of the voltage implies reduction of the torque applied to the mechanical loads. This may have an impact on your process (less debit for pump, less pressure for a juicer …) depending on the type of mechanical load. Here again at 380Vac nominal it shall not have significant consequence as 380V is in the tolerance of a 400Vac system. But if the 380Vac system is running at – 5 or -10% you may start to have consequences on your process.
- Some equipment have a “black and white behavior” according to voltage : typically relay / contactors .. that will switch off below a limit. You have to check that this type of equipment are able to operate as expected in the full range of voltage.

Hope it helps.

See Answer In Context

MathieuGuillot · ‎2020-09-02

Hello,

I don’t see any risk of major malfunction during operation at 380Vac nominal voltage for a system designed for 400Vac. Indeed large majority of equipment designed for 400Vac are applicable to 380Vac. But as we say “The Devil is in the Details.”

To ensure proper functioning of the future installation you should check few things:

I suggest to start your analysis by checking the tolerances of the supply voltage in both locations. What is the minimum voltage you may have today and what is the minimum voltage you may have tomorrow. If the tolerance of the supply in your new location is -10% you have to check that your production line can withstand temporary operation at 340Vac LL 200Vac LN. But may be your existing system is 400Vac -10% and the future 380Vac – 5% …
When you know the minimum voltage you can reach in the future, global efficiency and performance will depend on the type of loads.
- Some loads have a current proportional to the voltage (Typically resistor like heaters ..) for this loads the voltage reduction will means current reduction. From process point of view it will means longer operation for an heater to reach the same temperature.
- Some loads have a constant power, so voltage reduction means current increase. (Typically electronic converters such as variable speed drive, electronic power supply …) In that case there is no consequence on the process itself, but the supply and electrical equipment (cables, circuit-breaker, contactors…) upstream such loads need to handle the increase of the current. (Risk is overload trip for instance)
- Some loads have a more complex relationship between voltage and current : typically induction motors. Reduction of the voltage implies reduction of the torque applied to the mechanical loads. This may have an impact on your process (less debit for pump, less pressure for a juicer …) depending on the type of mechanical load. Here again at 380Vac nominal it shall not have significant consequence as 380V is in the tolerance of a 400Vac system. But if the 380Vac system is running at – 5 or -10% you may start to have consequences on your process.
- Some equipment have a “black and white behavior” according to voltage : typically relay / contactors .. that will switch off below a limit. You have to check that this type of equipment are able to operate as expected in the full range of voltage.

Hope it helps.

Gregoire_Brun · ‎2022-02-01

in line with @MathieuGuillot .

Please take care of the frequenly (50hz or 60 hz) of the network too

Gregoire Brun
Breaker Product Expert