Anyone replace LED drivers?

[Besoeker3]

But one line is similarly grounded, yes?

It is grounded back at the main distribution transformer.

 

[Besoeker3]

See my diagram in post #53 the only diagram I am unsure of is if there are old TT systems where at the pole center-tap is grounded.
I am fairly certain you can find 240/480 split phase in rural Scotland, and probably 220/440 in old parts of mainland EU and all the way east.
Rural parts of Australia and NZ also have 240/480.
But hopefully others will chime in and correct me as I probably missed something.

In Scotland it is 400/230V. For a residence it is 230V. For industrial their premises are 11kV at their input and then stepped down to what ever they need. Some I dealt with in cement works were 400V, 3,300V, and 11kV.

 

[electrofelon]

The IEC has standardized types of grounding systems in 60364-1, when doing any kind of comparison its helpful to take a minute and understand IEC terminology in terms of the NEC and then whatever country your working in or discussing etc;
It translates to NEC terminology like this,

Start at the secondary of a distribution transformer (utility side or a separately derived system)

The First Letter (I or T) indicates the relationship of the distribution transformer to ground.
T = direct connection of one point to earth.
I = all live parts isolated from earth, or one point connected to earth via a high impedance.

The second letter indicates the relationship of all exposed-conductive-parts and any equipment grounding conductors to a grounding electrode system.
T = direct electrical connection to a grounding electrode system independent of any other grounding electrode system.
N = direct electrical connection of the neutral point or a line conductor to the grounding electrode system and thus the equipment grounding conductors.

Subsequent letter with a dash - (if any) and describe the arrangement of neutral and equipment grounding conductor
S = Grounds and neutral (or grounded phase) are run separately all the way from the distribution transformer.
C = neutral (or grounded phase conductor) and equipment grounding provided by the same conductor

So what we typically have here under the NEC is called TN-C-S
T) Because at the secondary we have a direct connection of one point to ground;
N) We have direct electrical connection of the neutral point or a line conductor to the grounding electrode system and thus the equipment grounding conductors.
Then for the conductors
-C The utility neutral is combined with the equipment grounding conductor until the service disconnect.
-S After the service disconnect they are separate

Under the NEC a ungrounded system with ground detectors would be a IT system.


The main earthing systems in the UK TN-C-S,
but they also allow and have are TN-S and TT
TN-S is that Mtnelect fells dream, the neutral is bonded once at the secondary then everything is separate after that.
So for a 208/120 three phase service you'd have 5 wires from the utility.
TT is when a the neutral or one of the phases on the secondary is grounded to a ground rod at the pole but then that's it, its ran insulated after that, then at your house you establish a GEC connect all your equipment grounds to it but don't bond the neutral,
I am fairly certain this is how they do it in Japan.


In areas with allot of underground distribution the service lateral looks like our MV cable, a concentric coax type, for a TT system the neutral is insulated or what we call covered.

See my diagram in post #53 the only diagram I am unsure of is if there are old TT systems where at the pole center-tap is grounded.
I am fairly certain you can find 240/480 split phase in rural Scotland, and probably 220/440 in old parts of mainland EU and all the way east.
Rural parts of Australia and NZ also have 240/480.
But hopefully others will chime in and correct me as I probably missed something.

Thanks for the rundown, nice summary . Yeah I am familiar with that IEC terminology and designations, but I always forget what is what I have to look it up.

 

[Flicker Index]

Yeah the shell of a bayonet is connected to equipment ground, there are of course older Edison like bases
View attachment 2575671
While Europe (then Aisa then the rest of the world) standardized on 230V 50hz but thats it.
Whats not simple is all their earthing systems, unlike us they did not standardize on how AC systems are grounded or if they are even required to be, so they have all these different 'earthing systems'.

What we mandate here with a multi grounded neutral (MGN) (or ungrounded) on the utility side then floating neutral after the service mains is called 'Terra Neutral Combined - Separate' (TN-C-S)
However across the pond in various countries like Norway you can find systems where there is no connection between the equipment ground and the neutral or there is no neutral its a 230v delta secondary (IT) , or the utility floats the neutral and also provides an equipment ground (TN-S).
In remote rural areas with just single phase distribution I think its the same as here in a way you find split phase but they never use the 115V side for anything its just a ground reference at the pole.
In Places like Berlin and Spain the '220' was from a 220Y/127 system (now 230Y/133) so its not always a 230Y400.

See this guy's post. Interesting tidbits about Norway. https://forums.mikeholt.com/threads/ungrounded-system-egc.144120/post-2253449
Apparently, they have ungrounded 230v delta.

 

[tortuga]

See this guy's post. Interesting tidbits about Norway. https://forums.mikeholt.com/threads/ungrounded-system-egc.144120/post-2253449
Apparently, they have ungrounded 230v delta.

Yeah there is a fella that was from Norway some years back that would post about it.
I got interested in the whole topic of their 'earthing systems' when working with imported machinery and equipment from Europe.
Some thought European equipment required a 220 - 240V Line - Neutral potential.
Just like some old fluorescent lighting ballasts marked 120-277 actually required one of the wires to be at zero volts.
But it turns out their specs typically allow for anything from ungrounded to just about any grounding system you can think of.

 

[CoolWill]

Yeah there is a fella that was from Norway some years back that would post about it.
I got interested in the whole topic of their 'earthing systems' when working with imported machinery and equipment from Europe.
Some thought European equipment required a 220 - 240V Line - Neutral potential.
Just like some old fluorescent lighting ballasts marked 120-277 actually required one of the wires to be at zero volts.
But it turns out their specs typically allow for anything from ungrounded to just about any grounding system you can think of.

How does the electronics know if one line is grounded or not?

 

[Flicker Index]

How does the electronics know if one line is grounded or not?

Have you seen the inside of an electronic ballast? There is usually a fuse, on the "hot side", which almost never opens. If you connect it in a L-L system and if the non-fused side faults, it will cause a "ground fault" and may trip the entire circuit.

The fault will probably clear itself when the power is restored, but if it doesn't, what a nightmare it would be to track down the shorted ballast.

 

[CoolWill]

Have you seen the inside of an electronic ballast? There is usually a fuse, on the "hot side", which almost never opens. If you connect it in a L-L system and if the non-fused side faults, it will cause a "ground fault" and may trip the entire circuit.

The fault will probably clear itself when the power is restored, but if it doesn't, what a nightmare it would be to track down the shorted ballast.

But, then how do the 120-277 ballasts work on 208 or 240 L-L? It seems to me that 120-277 includes everything in between 120 and 277, no?

 

[tortuga]

But, then how do the 120-277 ballasts work on 208 or 240 L-L? It seems to me that 120-277 includes everything in between 120 and 277, no?

I should have said 120/277 (note the slash) and I am talking old first gen electronic ballasts late 90's, they had a EMI filter or MOV between what was expected to be a neutral and the equipment ground, I think pretty soon after that 100 -- 277 became a standard north American design supporting 240 delta or 208 supplies be it L-L , hi leg corner grounded or whatever.

 

[Flicker Index]

But, then how do the 120-277 ballasts work on 208 or 240 L-L? It seems to me that 120-277 includes everything in between 120 and 277, no?

120/277 light switch works for "in between" too and can be used for such thing as switching a single phase 230v motor fed from a corner ground 240v delta on one of the ground referenced leg. That same switch will turn the motor on/off even on a common household 240v power, but one leg would always be hot. There are lots of things that will work, but nonetheless not supposed to be done.
(the 120/277 rating on a switch means "dual application", not the same as the "slash rating" in the context of 120/240v breaker)

Also see this. This is straight out of application notes from Universal Lighting (now gone).

120/277 ballast would be fine connected L-N on 120v, 277v, or 240v (corner ground delta system), but that does not mean that lead polarity is irrelevant, so running on 240v L-L isn't the same thing.

I should have said 120/277 (note the slash) and I am talking old first gen electronic ballasts late 90's, they had a EMI filter or MOV between what was expected to be a neutral and the equipment ground, I think pretty soon after that 100 -- 277 became a standard north American design supporting 240 delta or 208 supplies be it L-L , hi leg corner grounded or whatever.

Lamp starting reliability maybe a thing of the past, but EMI, surge protection, and UL listing are all still relevant.

 

[CoolWill]

120/277 light switch works for "in between" too and can be used for such thing as switching a single phase 230v motor fed from a corner ground 240v delta on one of the ground referenced leg. That same switch will turn the motor on/off even on a common household 240v power, but one leg would always be hot. There are lots of things that will work, but nonetheless not supposed to be done.
(the 120/277 rating on a switch means "dual application", not the same as the "slash rating" in the context of 120/240v breaker)

Also see this. This is straight out of application notes from Universal Lighting (now gone).

120/277 ballast would be fine connected L-N on 120v, 277v, or 240v (corner ground delta system), but that does not mean that lead polarity is irrelevant, so running on 240v L-L isn't the same thing.

View attachment 2575760


Lamp starting reliability maybe a thing of the past, but EMI, surge protection, and UL listing are all still relevant.

That applies to 120/277 volt ballasts, but I haven't seen that in a long time. They are all now rated 120-277.

I'm not an English major, but to me "120/277" means 120 or 277. And "120-277" means 120 through 277.

 

[Flicker Index]

That applies to 120/277 volt ballasts, but I haven't seen that in a long time. They are all now rated 120-277.

I'm not an English major, but to me "120/277" means 120 or 277. And "120-277" means 120 through 277.

As I said, 120 to 277v L-N does not mean polarity free. You'll see that ballasts (for LED or fluorescent) have a black and a white lead, not two black leads, not two black/white striped leads.

Laptop adapters and phone chargers are international rated 100-240v 50/60Hz but they're designed for up to 240v floating above ground on either legs because there are ungrounded countries.