megloff11x
Senior Member
It's a bit out of my experience so I'll ask here. I was asked and didn't know the whole answer, and wasn't 100% sure of the bits that did ring a bell. Now I'll lose sleep until I know.
When you're calculating wire size & conduit needs for outdoor overhead lights (parking lots and parks/fields with illumination for night use):
1. What's the best or most used conduit material if you're going to bury it under the grass alongside or under the pavement of a lot or field? And what's the best insulation choice for the conductors? And how deep should you bury it?
2. I always get dyslexic on the bundling issue. If you need more wire than you have room for and have multiple conduit runs, how do you divvy up the various phases, neutral, and ground amongst the runs?
3. How much Voltage drop is allowed and how would you balance it if you have mutliple conduit runs?
4. You have to derate for temperature and bundling. Is it a good practice to consider the neutral a power carrying conductor to be on the safe side in case of the very likely harmonic or imbalanced load issues?
5. How is the tapping to the various lights usually handled where they go into the pole?
6. What's the best wiring plan to save on wire and have a good system? There's a park and parking lot, both with lights. the park has a perimeter and the parking lot will have lights throughout.
7. If you're using metal conduit, can/should it be used for the grounding or should you run a separate grounding conductor back to the main panel?
7. Am I missing any other considerations?
Some days I feel like the "Farside" kid whose brain is full. Other days I'm the one pushing on the door I should be pulling open...
Matt
When you're calculating wire size & conduit needs for outdoor overhead lights (parking lots and parks/fields with illumination for night use):
1. What's the best or most used conduit material if you're going to bury it under the grass alongside or under the pavement of a lot or field? And what's the best insulation choice for the conductors? And how deep should you bury it?
2. I always get dyslexic on the bundling issue. If you need more wire than you have room for and have multiple conduit runs, how do you divvy up the various phases, neutral, and ground amongst the runs?
3. How much Voltage drop is allowed and how would you balance it if you have mutliple conduit runs?
4. You have to derate for temperature and bundling. Is it a good practice to consider the neutral a power carrying conductor to be on the safe side in case of the very likely harmonic or imbalanced load issues?
5. How is the tapping to the various lights usually handled where they go into the pole?
6. What's the best wiring plan to save on wire and have a good system? There's a park and parking lot, both with lights. the park has a perimeter and the parking lot will have lights throughout.
7. If you're using metal conduit, can/should it be used for the grounding or should you run a separate grounding conductor back to the main panel?
7. Am I missing any other considerations?
Some days I feel like the "Farside" kid whose brain is full. Other days I'm the one pushing on the door I should be pulling open...
Matt