I would like to mount four 150 watt MH on a 5'x1.5"x7.5" crossarm mounted flat on the top of a 45' class 4 western red cedar pole. The fixture mounting height would be 40'. The cross arm would be treated LVL material attached flat on the top of the pole. With a standard V crossarm bracket. This will allow for a flat work area while changing bulbs or aiming fixtures. The EPA rating for the four fixtures totals 7.52 up to thirty degrees, which will be fine. According to the North American Wood Pole Council the ultimate resisting moment for the pole is 88,853 ft-lbs. The pole top circumference is 21". The pole will be set at 10% + 2', or 6' 6" deep. The ground level circumference is 38.28". The wind rating in our area is 90 mph.
Questions:
1. How are the EPA figures supplied by the fixture manufacturer derived?
2. What do the EPA figures indicate? ft.-lbs.?
3. Is the goal to find the total applied moment at a maximum wind speed in a given area?
4 .What percentage of the ultimate resisting moment is acceptable?
5. What calculations does a municipality usually require?
6. Is this a viable application?
Thanks, Brent
Questions:
1. How are the EPA figures supplied by the fixture manufacturer derived?
2. What do the EPA figures indicate? ft.-lbs.?
3. Is the goal to find the total applied moment at a maximum wind speed in a given area?
4 .What percentage of the ultimate resisting moment is acceptable?
5. What calculations does a municipality usually require?
6. Is this a viable application?
Thanks, Brent
