Definition of Polarized and Unpolarized AC Systems

[id_rather_be_welding]

Having now got hold of the 2 ISOs relating to electrical installations on small craft without having to fork out an arm and a leg (thanks to the pointers given elsewhere in this forum), I wonder if someone in the know of which there appear to be some in these parts could explain to me in nice simple terms the difference between a Polarized and Unpolarized AC System?

ISO13297 defines a Polarized System as a "system in which the neutral and live conductors are connected in the same manner to all terminals on devices or receptacles (socket outlets) in a circuit."

 

Thanks

[MoominPapa]

Having now got hold of the 2 ISOs relating to electrical installations on small craft without having to fork out an arm and a leg (thanks to the pointers given elsewhere in this forum), I wonder if someone in the know of which there appear to be some in these parts could explain to me in nice simple terms the difference between a Polarized and Unpolarized AC System?

ISO13297 defines a Polarized System as a "system in which the neutral and live conductors are connected in the same manner to all terminals on devices or receptacles (socket outlets) in a circuit."

 

Thanks

 

In an unpolarised system, there's no difference between the two supply conductors, instead of "neutral" and "live" there are just two "line" conductors which are interchangeable. On such a system bonding of neutral to earth is not possible. A polarised system keeps the two supply conductors distinct, so that live is always live, and neutral always neutral.

 

Next time you're in a French, supermarket, take a look at the "two plugs into one socket" adaptors. The design is such that the two supply conductors are the opposite way round on the two outlets. To someone used to the UK system, it looks very strange.

 

MP.

[ditchcrawler]

In an unpolarised system, there's no difference between the two supply conductors, instead of "neutral" and "live" there are just two "line" conductors which are interchangeable. On such a system bonding of neutral to earth is not possible. A polarised system keeps the two supply conductors distinct, so that live is always live, and neutral always neutral.

 

Next time you're in a French, supermarket, take a look at the "two plugs into one socket" adaptors. The design is such that the two supply conductors are the opposite way round on the two outlets. To someone used to the UK system, it looks very strange.

 

MP.

I have worked on American Supply vessels that were working in the North Sea that had this type of system, but I am going back 30 years.

[id_rather_be_welding]

In an unpolarised system, there's no difference between the two supply conductors, instead of "neutral" and "live" there are just two "line" conductors which are interchangeable. On such a system bonding of neutral to earth is not possible. A polarised system keeps the two supply conductors distinct, so that live is always live, and neutral always neutral.

Thanks for the speedy replies. So a Polarized supply is what is standard. Is the ISO not confused? This is the ISO verbatim:

3.11

polarized system

system in which the neutral and live conductors are connected in the same manner to all terminals on devices or receptacles (socket outlets) in a circuit

Am I missing something, or is this not defining an Unpolarized system - i.e. Live and Neutral are not differentiated?

I have worked on American Supply vessels that were working in the North Sea that had this type of system, but I am going back 30 years.

What is the benefit of an Unpolarised system for a boat? Is the supply halved between the 2 supplies?

 

Thanks again

[Chris Pink]

"3.11

polarized system

system in which the neutral and live conductors are connected in the same manner to all terminals on devices or receptacles (socket outlets) in a circuit"

 

 

Am I missing something, or is this not defining an Unpolarized system - i.e. Live and Neutral are not differentiated?

 

This is saying that if live is connected to pin 1 (say) in every connector ie live and neutral are never swapped then this is their definition of a polarised system, it makes no statement about neutral-earth bonding though, obviously, this is the only system under which neutral-earth bonding is possible (without a big bang)

 

What is the benefit of an Unpolarised system for a boat? Is the supply halved between the 2 supplies?

 

There is none.

 

UK 240V connectors are polarised.