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#15455 - 10/18/02 04:26 AM Huge amount of Christmas Lights
ctolbert Offline

Registered: 08/09/01
Posts: 33
Loc: Cumming, GA USA
I feel like I'm in that movie "Christmas Vacation." I was thrown a project that is huge and already started. I would love some comments about the direction it's heading.

--64 light strands (700 watt 120vac incandecent)
--600 amp feeder with 16 x 30 amp breakers allocated for above strands.
--4 strands per breaker
--each strand controlled on/off with 10 amp omron micro relay with a 2 times a second switching rate.
--relays controlled by plc in predetermined pattern.

My biggest concern right the switching speed and the inrush from the lamps as they are switched.

Any comments would be appreciated,

Carl Lee Tolbert
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#15456 - 10/18/02 09:38 AM Re: Huge amount of Christmas Lights
Pearlfish Offline

Registered: 09/12/02
Posts: 83
Loc: Chicago Ridge, Il, USA
If the inrush becomes a problem, have your programmer input a 20+ millisecond delay into selected rungs. It will be almost imperceptable to the eye. If you have a large number of rungs, the lights will "sweep" on and still look nice!

[This message has been edited by Pearlfish (edited 10-18-2002).]

#15457 - 10/18/02 12:36 PM Re: Huge amount of Christmas Lights
Scott35 Offline

Broom Pusher and

Registered: 10/19/00
Posts: 2724
Loc: Anaheim, CA. USA
Interesting subject!!!

Could you add some more data so we can have a better understanding of everything?

Stuff like System type [1 phase, 3 phase], exact rating of each lamp [or lamps if various types], inrush level or cold Resistance level, flashing in sequence, randomly or all at once, overall length of circuits / feeders / subfeeds, available KVA, switching relay's duty rate and other specs, and do the lamps have to be at 100% intensity when on, or can they drop to 90% intensity.

Scott S.E.T.
Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!


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