Pole Lights Calculation

[weressl]

Without a knowledge of data on the power cable connecting the highway pole lights, those folks are making only an approximation.

Is this non-Newtonian, ayurvedic science? What does power cable data has to do with the load's power factor? (Hint: infinitesimally little.)

 

[Sahib]

Is this non-Newtonian, ayurvedic science? What does power cable data has to do with the load's power factor? (Hint: infinitesimally little.)

No, not a kind of laetrile treatment for cancer, but as the OP stated, the pole light is for highway and so long length of power cable would be involved and so significant power loss in the power cable to be included in the calculation for the total number of poles.

 

[weressl]

No, not a kind of laetrile treatment for cancer, but as the OP stated, the pole light is for highway and so long length of power cable would be involved and so significant power loss in the power cable to be included in the calculation for the total number of poles.

Hogwash. You need to (up)size the cable for voltage drop, otherwise the lights won't work, hence you will (automatically) minimize the power loss due to line losses. Again an infinitesimally small number to be concerned.

 

[Sahib]

Hogwash. You need to (up)size the cable for voltage drop, otherwise the lights won't work, hence you will (automatically) minimize the power loss due to line losses. Again an infinitesimally small number to be concerned.

Some numerical example will clarify the matter.

 

[weressl]

Some numerical example will clarify the matter.

Knock yourself out!

Get the data first though, the OP did not post ANY values nor did he indicate what distances maybe involved. Of course 'educated' guesses can be made.

 

[Sahib]

Knock yourself out!

Get the data first though, the OP did not post ANY values nor did he indicate what distances maybe involved. Of course 'educated' guesses can be made.

It is a bad precedent to give suggestion for the OP as to the total number of poles then: in another similar circumstance, if the OP comes with an exact number for ''transformer KVA capacity/pole lights KVA'', then he is likely to adopt it based on the earlier suggestions, neglecting the power loss in the cables thereby overloading the transformer.

 

[topgone]

It is a bad precedent to give suggestion for the OP as to the total number of poles then: in another similar circumstance, if the OP comes with an exact number for ''transformer KVA capacity/pole lights KVA'', then he is likely to adopt it based on the earlier suggestions, neglecting the power loss in the cables thereby overloading the transformer.

Did you review your post before you clicked submit? How can an error on the sizing of the cables/ power lost in the cables overload the transformer?

 

[Sahib]

Did you review your post before you clicked submit? How can an error on the sizing of the cables/ power lost in the cables overload the transformer?

Take, for example, transformer capacity 180 KVA and pole light KVA=18. Then the no. of poles=180/18=10. But this assumes there is no power loss in the connecting cables, fuses etc., This assumption is not always workable and so there is concern for transformer overloading.

 

[weressl]

It is a bad precedent to give suggestion for the OP as to the total number of poles then: in another similar circumstance, if the OP comes with an exact number for ''transformer KVA capacity/pole lights KVA'', then he is likely to adopt it based on the earlier suggestions, neglecting the power loss in the cables thereby overloading the transformer.

If we were close friends I would ask you the question in banter: "Are you some kind of a special stupid?", but since we aren't, I won't.

As I pointed out before it is not possible to have losses large enough to be the concern, because voltage drop would cause the whole design to be unworkable in the first place. And no, YOU supply a calculated design first to prove your point.

 

[topgone]

Take, for example, transformer capacity 180 KVA and pole light KVA=18. Then the no. of poles=180/18=10. But this assumes there is no power loss in the connecting cables, fuses etc., This assumption is not always workable and so there is concern for transformer overloading.

:jawdrop:I would admire people who have the courage to admit the possibility that sometimes they can loose touch of the realities/ truths.

Here. Say your lines were smaller than what they should be and will give you a total voltage drop of 20% of the source before it reaches the first lighting pole. Probably, your lighting fixtures will fire up with 80% voltage but the amperage will be lower due to the lower voltage. The remaining lighting posts might or might not even light up resulting into a lower current draw.

Lower amps at the source transformer X source voltage X PF will surely tell you the consumption ain't gonna be higher, hence no overloading occurs.

 

[Sahib]

If we were close friends I would ask you the question in banter: "Are you some kind of a special stupid?", but since we aren't, I won't.

I do not know whether it is in your temperament or because of the disease you are suffering from currently that you are making such statements as above but I want to warn you: demeaning a member in a friendly guise or not is against the forum rules.

As I pointed out before it is not possible to have losses large enough to be the concern, because voltage drop would cause the whole design to be unworkable in the first place. And no, YOU supply a calculated design first to prove your point.

You are missing the point: it is not the voltage drop but the power loss taking place in all other components ( also due to occasional transformer primary voltage hike besides other factors such as power loss in cables) that is of concern when the transformer is fully loaded by the pole lights.

 

[weressl]

I do not know whether it is in your temperament or because of the disease you are suffering from currently that you are making such statements as above but I want to warn you: demeaning a member in a friendly guise or not is against the forum rules.

Offense is like beauty, it is in the mind of the recipient. If it is true, it isn't an offense. If it is not true, then there is nothing to be offended by it....

You are missing the point: it is not the voltage drop but the power loss taking place in all other components ( also due to occasional transformer primary voltage hike besides other factors such as power loss in cables) that is of concern when the transformer is fully loaded by the pole lights.

As at least another poster agreeing with me, it is you who seem to be lacking practical engineering knowledge in determining what is significant to be concerned about and what aspects of the multitude of physical phenomena that are either tangential or insignificant to be concerned about. The first principle in engineering is the ability to distinguish between what has impact on a problem and what are those that can be ignored.

In this case - as I am trying to explain it to you - but feel like banging against my head against a brick wall - the undersized cable(for the distance) would cause a voltage drop that would make the ballast unable to initialize or sustain the arc in an HID fixture. That could be the first or second and all subsequent poles if they are connected in series.

You have repeatedly brought up identically trivial issues on a multitude of posts and thus misleading those members of the technical community who do not have the technical depth to differentiate substance from chaff. IMO you should be considered for removal from the membership. Your insensible contributions actually are harmful.

 

[weressl]

I do not know whether it is in your temperament or because of the disease you are suffering from currently that you are making such statements as above but I want to warn you: demeaning a member in a friendly guise or not is against the forum rules.

Your mention of my illness in this context is highly insensitive and offensive.

If I truly believed that you are mentally ill I would not have made a joke of it. Alas I did, and if I were mistaken, I apologize.

 

[Sahib]

Offense is like beauty, it is in the mind of the recipient. If it is true, it isn't an offense. If it is not true, then there is nothing to be offended by it....

Do not play with words.

As at least another poster agreeing with me, it is you who seem to be lacking practical engineering knowledge in determining what is significant to be concerned about and what aspects of the multitude of physical phenomena that are either tangential or insignificant to be concerned about. The first principle in engineering is the ability to distinguish between what has impact on a problem and what are those that can be ignored.

In this case - as I am trying to explain it to you - but feel like banging against my head against a brick wall - the undersized cable(for the distance) would cause a voltage drop that would make the ballast unable to initialize or sustain the arc in an HID fixture. That could be the first or second and all subsequent poles if they are connected in series.

You have repeatedly brought up identically trivial issues on a multitude of posts and thus misleading those members of the technical community who do not have the technical depth to differentiate substance from chaff. IMO you should be considered for removal from the membership. Your insensible contributions actually are harmful.

The gist of my argument is that all loads to be taken into account so that there is no possibility of overloading the transformer; simply counting the KVA of individual pole light for fully loading the transformer is not correct. You yourself were against fully loading the transformer that way:

I would not load up a transformer to it's full capacity

So what is that separates you from me in etiquette?

An unmitigated imprudence on your part.

 

[GoldDigger]

If I truly believed that you are mentally ill I would not have made a joke of it. Alas I did, and if I were mistaken, I apologize.

Subtle.

Sent from my XT1080 using Tapatalk

 

[Sahib]

To conclude:
80% loading of transformer is an industrial practice. This may be adopted in the OP's case.

 

[mivey]

To conclude:
80% loading of transformer is an industrial practice. This may be adopted in the OP's case.

That concludes nothing. With a static load, the transformer should be fully utilized. Your "room for growth" means nothing if there is no growth. Rules of thumb mean nothing without the rule parameters.

Besides, the line loss is probably 3-4% as a worst case and probably more in the 2-3% or less in practice.

 

[kingpb]

A quote that comes to mind;

"Stupid is as stupid does"

Gotta love gump!

 

[Sahib]

That concludes nothing. With a static load, the transformer should be fully utilized. Your "room for growth" means nothing if there is no growth. Rules of thumb mean nothing without the rule parameters.

Besides, the line loss is probably 3-4% as a worst case and probably more in the 2-3% or less in practice.

A quote that comes to mind;

"Stupid is as stupid does"

Gotta love gump!

This is silly, for neither I nor the Bulldozer talked about the 'room for growth' about the transformer.

 

[mivey]

This is silly, for neither I nor the Bulldozer talked about the 'room for growth' about the transformer.

Silly would be buying 25% more transformer than you will ever need. Do you buy five new tires for your car when it is time for new tires?