ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
dsk 13
Admin 8
Recent Posts
Grid problem??
by annemarie1. 08/21/17 01:10 PM
Bathroom electrical
by doc. 08/19/17 06:53 AM
electircal ageing test on IPC
by SIAME. 08/15/17 02:43 AM
electrical aging test on IPC
by gfretwell. 08/15/17 12:27 AM
"Line level" audio on Cat 5?
by gfretwell. 08/08/17 10:39 PM
New in the Gallery:
Gallery Test
Popular Topics(Views)
240,089 Are you busy
175,706 Re: Forum
167,916 Need opinion
Who's Online Now
0 registered members (), 69 guests, and 8 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
Page 1 of 2 1 2
#203442 - 09/29/11 07:15 PM light/timer puzzle.  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,103
Estero,Fl,usa
Here's the deal. There is a string of lights on poles in a community connected with URD (208 HID).
They are on a dusk to dawn timer.
The customer now wants 2 of them to go off at midnight and they don't want to dig up the place to add another conductor.
Ideas?

Two come to mind with me.

An X-10 solution ... ugh. (lightning being the biggest issue)

A battery operated timer in the poles that go off at midnight but I don't find that timer suitable for HID. (plenty for 5-15 plugs)

Any other ideas or a link to the battery timer.


Greg Fretwell

Work Gear for Electricians and the Trades

#203443 - 09/29/11 08:14 PM Re: light/timer puzzle. [Re: gfretwell]  
sparkyinak  Offline
Member
Joined: Jul 2007
Posts: 1,327
Alaska
Slave a relay to your timer


"Live Awesome!" - Kevin Carosa

#203444 - 09/29/11 08:22 PM Re: light/timer puzzle. [Re: gfretwell]  
HotLine1  Offline


Member
Joined: Apr 2002
Posts: 6,858
Brick, NJ USA
Greg:
How about two (2) time delay relays. One at each of the poles.

208 volt 'on' (dusk) starts time down sequence to 'open' load at determined time. 208 volt 'off',(dawn) relay drops back to the 'on' position and sequence repeats.

Key is determining the 'on' time with the changing season?


John

#203445 - 09/29/11 09:29 PM Re: light/timer puzzle. [Re: gfretwell]  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,103
Estero,Fl,usa
That was the first thought but you would need an adjustable TD relay and it would be one more thing they would have to be messing with all the time.

I have some timers that use an electronic clock that will run years on a 9v battery but I can't find one that actually supports anything but a 5-15 and this probably needs to be in a 3R box. I guess if it is small enough it could be in the hand hole.


Greg Fretwell

#203446 - 09/29/11 09:54 PM Re: light/timer puzzle. [Re: gfretwell]  
HotLine1  Offline


Member
Joined: Apr 2002
Posts: 6,858
Brick, NJ USA
Greg:
Don't you have to adjust the electronic clock, or is it astronomical?



John

#203447 - 09/29/11 10:27 PM Re: light/timer puzzle. [Re: gfretwell]  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,103
Estero,Fl,usa
The only time that is important is that it shuts off at midnight. You could set the on time to 1600 but the light still wouldn't come on until the others did.


Greg Fretwell

#203449 - 09/29/11 11:05 PM Re: light/timer puzzle. [Re: gfretwell]  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,103
Estero,Fl,usa
I have found some regular timers with electronic clocks that say they can hold the clock for up to 96 hours in a power failure. That might do the trick.

Something like a Paragon EC7000 in double pole.


Greg Fretwell

#203451 - 09/30/11 12:46 AM Re: light/timer puzzle. [Re: gfretwell]  
twh  Offline
Member
Joined: Mar 2004
Posts: 916
Regina, Sask.
Constant power to everything and put the dusk to dawn lights on photo cells. Then, put the two lights to be turned off at midnight on time clocks.

How about LED lights - they are DC after all. AC runs all lights, positive polarity runs some and negative polarity runs others.

Have you considered directional boring? They can hit a one foot hole and it might be cheaper than any other solution.


#203452 - 09/30/11 02:43 AM Re: light/timer puzzle. [Re: gfretwell]  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,103
Estero,Fl,usa
They have no interest in replacing a couple dozen brand new lights with LEDS. Putting everything on photo cells was considered but they would still have to buy 2 timers.

Digging again is not that tough but it is $1200 by the time they add the conductor.

I sent them off with the Paragon idea. $250 or so in parts. Lets see how that goes over. It says it can handle a 4 day power failure and the storage element is a big capacitor so it should charge up OK during the light on interval.

If someone has a simpler solution I am all ears.


Greg Fretwell

#203453 - 09/30/11 04:03 AM Re: light/timer puzzle. [Re: gfretwell]  
Scott35  Offline

Broom Pusher and
Member
Joined: Oct 2000
Posts: 2,707
Anaheim, CA. USA
There are several techniques for an overall Control Application, with Complexity ranging from Moderate, to Advanced.

After reviewing the Issue at hand, I thought about the same approach as "twh" listed:

"Constant power to everything and put the dusk to dawn lights on photo cells. Then, put the two lights to be turned off at midnight on time clocks."

This would be the simplest, and most reliable method.

If the Two Timed-Off Fixtures are the first Two in the Circuit,... i.e.:

(----[Ckt.Bkr.]----{Fixt.1}----{Fixt.2}----{Fixts 3,4,5,6,7,8...})

a Photocell could be placed at Fixture #2, which would perform _Dusk-To-Dawn_ control of the remaining Fixtures on the Circuit.
The same Photocell may also control the second Fixture - performing the _On-At-Dusk_ function via the Photocell Load Side Circuit.
This Circuit would be connected to the Fixture through a Time Clock's Dry Contacts.
The Clock Circuit would be connected to the un-switched (Line) Side of the Branch Circuit.
Time Schedule would be
A: "ON" at 16:00:00 AST / ADT,
B: "OFF" at 23:59:59 AST / ADT.

The first Fixture would have both a Photocell and a Time Clock, however the Photocell on this Fixture will _NOT_ control downstream loads (only the first Fixture).

A slightly more detailed version of this Control Scheme would incorporate a 2 Pole Electrically Held Contactor at the 2nd Fixture, with the Contactor's Coil being driven (Controlled) by the Photocell.

This method also eliminates the _"Live Screwshell"_, or "_Shocking Experience_" often found with Lamps being connected across 2 Pole Circuitry.
As compared to simply controlling one of the Two Ungrounded Conductors via a common Photocell, the Contactor would open both Ungrounded Conductors of the 208V 1 Phase 2 Wire Branch Circuit.

Use NEMA 3R Enclosures for the Time Clock(s) and Contactor(s). Mount a Stem-Type Photocell to the exterior of the Enclosure(s), with a clear aim at Geographic North.

On a somewhat related note, I am curious if daily outages may cause operational issues with Electronic Time Clocks.
This is in response to the option of running the Timers in Battery Backup mode during Daylight Hours... i.e.:

"I have found some regular timers with electronic clocks that say they can hold the clock for up to 96 hours in a power failure. That might do the trick.
Something like a Paragon EC7000 in double pole."


An advanced technique would involve Carrier Current Controls (like X10 Devices), setup in much the same way as the technique described above.
Drawbacks will be the Lightning Surges that frequent the State of Florida.

The best option overall may be to have the Landscapers provide some Trenching for you between certain Poles, and you (or your Crew) Install some PVC + several #10 CU Conductors.

*** CYA NOTICE ***
Notice the Qualifying Text "Have The Landscapers Provide Trenching For You"
This should eliminate / reduce the Back-Charge Issues + Nastygram submissions oriented around the repair / replacement of Plants, Grass and Groundcover.

-- Scott


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

Page 1 of 2 1 2

Member Spotlight
Grover
Grover
Sebago, ME, USA
Posts: 109
Joined: January 2005
Show All Member Profiles 
Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.033s Queries: 16 (0.003s) Memory: 0.8239 MB (Peak: 1.0062 MB) Zlib enabled. Server Time: 2017-08-22 15:01:52 UTC