Lamp Posts

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frank_n

frank_n

Senior Member
Location
Central NJ
I am bidding on a job where the owner wants 9 lamp posts. There will be 9 32 x 32 x 42(H) brick posts and each post will have a 180-watt fixture. The length of the circuit will be no more than 200 feet.

I plan on running one 20-amp circuit with #6 THWN in a 1" PVC. The lights will be controlled by a photo-electric eye.

I know I am going to have to stub up from the ground with the PVC, but I am not sure how to make the connection from the PVC to the Light Fixture. I know I have to install a Pier Mount.

Are the wires connected with conduit, or just hang free between the PVC and the fixture?

Frank
 
frank_n

frank_n

Senior Member
Location
Central NJ
iwire said:
You are required to provide a box for the fixture.


You could use something like this

9" Post/Deck Mount Support for Outdoor Light Fixtures


Keep in mind that if you run 6 AWG for your circuit conductors you must run a 6 AWG EGC per 250.122(B).

For the wattage and length I would use 10 AWG.
Click to expand...

I have never seen something like that on top of a brick post before.

#10 THWN has a voltage drop of 5.4%
#8 THWN has a voltage drop of 3.5%
#6 THWN has a voltage drop of 2.2%

Since 210.19(A)(1) FPN No.4 says the max voltage drop of the branch circuit should not exceed 3% I planned on using #6. FPN are part of the Code, not suggestions (am I right?).

Thanks for catching my mistake on 250.122(B)

Frank
 
LarryFine

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
You can always stagger the wire sizes: #6 to the first two (or three), #8 to the next two, #10 to the next two, and #12 to the last three (or two.)
 
2

220/221

Senior Member
Location
AZ
IMO, the wire size and conduit is way over killed.

3/4" and 10's will do it.


Stub up into the center of the piers and terminate in a 4/0 box mounted flush with the top.

I'd also use a contactor and keep the load off the pcell.

180 watts is over kill too. 3, 60 watt incandescants? Use 3, 13W cfl's. It will save a lot of maintenance and energy over the years.
 
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Dolfan

Dolfan

Senior Member
220/221 said:
IMO, the wire size and conduit is way over killed.

3/4" and 10's will do it.


Stub up into the center of the piers and terminate in a 4/0 box mounted flush with the top.

I'd also use a contactor and keep the load off the pcell.

180 watts is over kill too. 3, 60 watt incandescants? Use 3, 13W cfl's. It will save a lot of maintenance and energy over the years.
Click to expand...

Glenn Beck would not agree on the cfl's
 
frank_n

frank_n

Senior Member
Location
Central NJ
220/221 said:
IMO, the wire size and conduit is way over killed.

3/4" and 10's will do it.
Click to expand...

What about the Voltage Drop?

220/221 said:
180 watts is over kill too. 3, 60 watt incandescants? Use 3, 13W cfl's. It will save a lot of maintenance and energy over the years.
Click to expand...

If I use the cfl's I can use #12's. :D

I'm wondering how many people here think I should ignore the Voltage Drop. Isn't the FPN a requirement and not a suggestion? How will I ever pass inspection if it is a requirement?

Frank
 
M

MrMilbank

Member
Location
between LB and Head
spec it for cfls and someone puts in an incandescent a few years from now. when they got problems you dont wanna hear about it. i would would stagger the wire sizes each within the 3% tolerance rated at the max fixture wattage.

and does that pier mount need to be UL listed/labeled??
 
J

JES2727

Senior Member
Location
NJ
Frank,
Take a look at 90.5(C) regarding the Fine Print Notes.
I agree that #6's are overkill for this application.
 
mark32

mark32

Senior Member
Location
Currently in NJ
I like 220/221's suggestion about using a contactor in conjunction with the photocell, I must ask what a 4/0 box is though. Also, never having done such an install, I can imagine stubbing pvc up into a pier mount but I then cannot imagine connecting that to a box. I've seen pier mounts but I can't see fitting a box into one.
 
frank_n

frank_n

Senior Member
Location
Central NJ
mark32 said:
I like 220/221's suggestion about using a contactor in conjunction with the photocell, I must ask what a 4/0 box is though. Also, never having done such an install, I can imagine stubbing pvc up into a pier mount but I then cannot imagine connecting that to a box. I've seen pier mounts but I can't see fitting a box into one.
Click to expand...

A 4/0 box is a round 4 inch box. I don't think the Pier Mount would mount to the box, but mount over it.

Frank
 
K8MHZ

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
frank_n said:
What about the Voltage Drop?



If I use the cfl's I can use #12's. :D

I'm wondering how many people here think I should ignore the Voltage Drop. Isn't the FPN a requirement and not a suggestion? How will I ever pass inspection if it is a requirement?

Frank
Click to expand...

Just the oppostite:

7. Fine Print Note (FPN). A Fine Print Note contains explanatory material intended to clarify a rule or give assistance, but it isn't a Code requirement.
Click to expand...

That being said, I always try to maintain a 3 percent or less drop, 5 percent being max. On line calculators make the design easy. Trust me, years down the road, the customers will be glad you did the extra work.
 
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celtic

celtic

Senior Member
Location
NJ
In regards to the question of FPNs....they ARE "code" here in NJ:

*** THIS FILE INCLUDES ALL REGULATIONS ADOPTED AND PUBLISHED THROUGH THE ***
*** NEW JERSEY REGISTER, VOL. 41, NO. 7, APRIL 6, 2009 ***
​
TITLE 5. COMMUNITY AFFAIRS
CHAPTER 23. UNIFORM CONSTRUCTION CODE
SUBCHAPTER 3. SUBCODES
N.J.A.C. 5:23-3.16 (2009)
5:23-3.16 Electrical subcode
(a) Rules concerning the subcode adopted are as follows:
1. Pursuant to authority of P.L. 1975, c. 217, as modified by P.L. 1996, c. 53, the Commissioner hereby adopts the model code of the National Fire Protection Association, known as "The National Electrical Code 2008" as the electrical subcode for New Jersey.
i. Copies of this code may be obtained from the sponsors at NFPA, One Batterymarch Park, Quincy, Massachusetts 02269.
2. The National Electrical Code 2008 may be known and cited as "the electrical subcode."
i. Codes and standards referenced in the Fine Print Notes (FPNs) of the electrical subcode (NEC 2008) shall be considered adopted by reference to the extent prescribed by each related section. These codes and standards also are printed in DCA Bulletin #09-1, which contains a list of adopted codes and standards that are applicable to the enforcement of the electrical subcode.
Click to expand...
http://www.state.nj.us/dca/codes/code_assist_internet/barrier_free/pdf/sub_3_tech_amend_4_20_091.pdf
 
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