Practicality of 400 volt equipment

[Cookie]

Would it be practical, or technically possible to economically mass produce 400 volt single phase consumer goods? Light bulbs, kettles, heaters, chargers, TVs, hobs, vacuum cleaners, washers, dryers, microwaves, tools, ect ect?

I'm thinking this would save a lot of copper and make wiring both easier and safer. A 1mm2 cable on a 10 amp breaker would give 4,000 watts of power.

 

[Pete999]

Would it be practical, or technically possible to economically mass produce 400 volt single phase consumer goods? Light bulbs, kettles, heaters, chargers, TVs, hobs, vacuum cleaners, washers, dryers, microwaves, tools, ect ect?

I'm thinking this would save a lot of copper and make wiring both easier and safer. A 1mm2 cable on a 10 amp breaker would give 4,000 watts of power.

I'm confused Mate by your conclusions.

 

[R-fur]

UK regulation 559.5.1.201 limits lamp holders to 250V.
The biggest cost with cable is usually the installation so reducing the cable size would not save that much. 400V accessories would be bigger and more expensive.

 

[Julie.]

It doesn't really matter, different places may settle on different voltages to suit their situation, higher voltages will have issues/costs associated with risk of shock or additional insulation needs etc. Lower voltages with lower shock risk, higher losses and additional costs of conductors etc.

What balance you choose is up to you. In the main internationaly the standard throughout the world is in the 200-250v range - commonly 230v .

This is generally the best balance between all the factors, now it is the main standard most equipment is designed for this voltage, therefore more countries use it, so it's more of a standard, etc.

However there are some countries that are an exception to that in the 110/117v range, these are often purely historical, but once again once in this loop standard voltage - more products - more of a standard etc.

 

[Cookie]

I'm confused Mate by your conclusions.

400 volt single phase delivers more power for the copper; also dispensing of the need for a neutral (5th wire) within the installation further saves cost plus all the safety benefits of coming from a TN-S supply.

 

[Cookie]

UK regulation 559.5.1.201 limits lamp holders to 250V.
The biggest cost with cable is usually the installation so reducing the cable size would not save that much. 400V accessories would be bigger and more expensive.

Can't T&E take 230 volts line to earth? How much does 1mm2 T&E cost vs 2/5mm2 T&E per meter?

 

[Cookie]

It doesn't really matter, different places may settle on different voltages to suit their situation, higher voltages will have issues/costs associated with risk of shock or additional insulation needs etc. Lower voltages with lower shock risk, higher losses and additional costs of conductors etc.

What balance you choose is up to you. In the main internationaly the standard throughout the world is in the 200-250v range - commonly 230v .

This is generally the best balance between all the factors, now it is the main standard most equipment is designed for this voltage, therefore more countries use it, so it's more of a standard, etc.

However there are some countries that are an exception to that in the 110/117v range, these are often purely historical, but once again once in this loop standard voltage - more products - more of a standard etc.

Agree. Though would 400 volt as a standard cost more then having 230 volts as a standard?

 

[DPG]

Bizarre idea. And why stop at 400V? Go for 1500V and save even more copper!!

 

[Cookie]

Bizarre idea. And why stop at 400V? Go for 1500V and save even more copper!!

400 volts is already in place, above 1000 volts installations require significantly more complex insulation for guard against partial discharge plus the disconnection times would be difficult if not impossible to achieve.

 

[Julie.]

400 volts is already in place, above 1000 volts installations require significantly more complex insulation for guard against partial discharge plus the disconnection times would be difficult if not impossible to achieve.

Why - many large industrial sites use 3.3kV motors and so on.

The voltage isn't fixed at 230 (or 110) - that's just the most suitable for most end users taking into account the factors.

Like why we use 3 phase and not 7 phase and so on - it achieves the best balance given the technology we have

 

[Cookie]

Why - many large industrial sites use 3.3kV motors and so on.

The voltage isn't fixed at 230 (or 110) - that's just the most suitable for most end users taking into account the factors.

Like why we use 3 phase and not 7 phase and so on - it achieves the best balance given the technology we have

Right, but 3.3kv with EPR insulation, stress cones and OCPDs to achieve rapid disconnection. The added cost and complexity would outdo any copper savings of using 3.3kv in residential and commercial.

400 volts on the other hand uses PVC insulation and at 230 volts to ground can use standard MCBs.

 

[Julie.]

Right, but 3.3kv with EPR insulation, stress cones and OCPDs to achieve rapid disconnection. The added cost and complexity would outdo any copper savings of using 3.3kv in residential and commercial.

400 volts on the other hand uses PVC insulation and at 230 volts to ground can use standard MCBs.

but if you are going to start using phase to phase voltages, then you must start distributing 3 phase supplies - that's a two fold increase in the amount of copper used, plus all switchgear would be three phase etc.

That is a significant increase in costs - a 1.73 reduction in cable size balancing a 2 fold increase in the number of cables

 

[Cookie]

but if you are going to start using phase to phase voltages, then you must start distributing 3 phase supplies - that's a two fold increase in the amount of copper used, plus all switchgear would be three phase etc.

That is a significant increase in costs - a 1.73 reduction in cable size balancing a 2 fold increase in the number of cables

No necessarily- you could drop two phases and an earth at each property.

100 x 230 =23,000va / 400 volts= 57.5 amps or 63 amp main fuse.

3 phase would give 33 amps per phase or a 35 amp main fuse.

In both cases the main would use thinner copper, and in the 3 phase example the number of wires do not change in that a 4th neutral is provided as is.

 

[Julie.]

No necessarily- you could drop two phases and an earth at each property.

100 x 230 =23,000va / 400 volts= 57.5 amps or 63 amp main fuse.

3 phase would give 33 amps per phase or a 35 amp main fuse.

In both cases the main would use thinner copper, and in the 3 phase example the number of wires do not change in that a 4th neutral is provided as is.

In which case you cannot use 230V equipment!

it's only 400V in relation to a three phase circuit - each breaker is only operating at 230V if you use a single breaker then it must be 400V

All UK domestic equipment is 230v, switches etc

Yes SOME industrial kit is rated at 660V - but even that isn't sufficient, you would need 800v three phase kit for each breaker to open single phase 400V (700V but that's not standard)

A three phase set of breakers does not mean each is capable of opening 400V

 

[Pete999]

Why - many large industrial sites use 3.3kV motors and so on.

The voltage isn't fixed at 230 (or 110) - that's just the most suitable for most end users taking into account the factors.

Like why we use 3 phase and not 7 phase and so on - it achieves the best balance given the technology we have

Sorry Julie disagree with your reasoning