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View Full Version : I want to put a switch on some lights


OKSooner
01-22-2012, 01:28 PM
Hi all,

Some of you guys have been helpful in a project I'm doing right now. It's my first residential lighting job at a really nice house out in the suburbs and I want to get it right.

I had submitted a thread a few days back about using a dimmer switch on some lights. Bad idea for reasons that were explained well. (The other bad idea I had was using conduit to go into a porch area, but that's another story.)

I still would like to give my client some control over a couple of 50w lights in a certain place.

How about just putting a 20A switch on the circuit? Has anyone done anything like that?

Thanks

RLI Electric
01-22-2012, 09:58 PM
I hate to be redundant, but I think more information is needed than that. Are these 50 watt lights line voltage or low voltage? Are you talking a 20 amp toggle switch or some kind of dimmer. I can't think of any reason in a residence where you may need a 20 amp switch. I am sure any lighting you are looking to control is only on a 15 amp circuit.

David Gretzmier
01-22-2012, 10:09 PM
we have put switches on the ground level for gutter mount lights that are on dormers when folks have guests in those bedrooms. we install a switch in a metal red dot box, mount it on the wall and run conduit to the ground and then direct bury from there. I use a standard 120v 15 or 20 amp switch, just break one of the legs of the LV circuit, and we put a red dot bubble cover over the whole thing and make sure the gasket is in place properly. works fine and no problems.

jbailey52
01-22-2012, 11:27 PM
How about installing the ABT zone controller. You can split the lights into 3 zones and control them via remote control. You can even just buy the keychain remote also
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Lite4
01-23-2012, 05:40 AM
The ABT is fine to go with also, but might be overdoing it if you are just switching a couple lights.

jbailey52
01-23-2012, 09:17 AM
My thought was since he needs to switch a couple lights he may as well add that 'wow' factor for the customers and control the whole system with remote. Cheaply also.
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OKSooner
01-23-2012, 09:34 AM
Can I use this thing with a transformer that's outdoors?

NightScenes
01-23-2012, 04:09 PM
You can use just about any normal 15 amp switch on the secondary side to control a few lights. You can also use a low voltage dimmer if you want to cut it back a little, no problem.

Steve Atkinson
01-23-2012, 06:01 PM
Paul,

Do you have a supplier for a good low-voltage dimmer??? I have been searching high and low for some time. Someone said the Lutron is good for low-current flow, but I do not believe will work on 12v +/-

Mike & Lucia
01-25-2012, 11:12 PM
Steve,
I use the Zane 12 volt dimmer for this application. (I'm sure that's what Paul is referring to, also). The unit is a small rotary style dimmer, and works by breaking one leg on the 12 volt feed. I test voltage with the dimmer at 100% and mount a weather proof box wherever needed - trying to keep it inconspicuous but also convenient.
I don't know who you distributors are on the left coast, but get in touch with Gerry at www.terradek.com and you'll have your switch, pronto.
Mike

Steve Atkinson
01-25-2012, 11:35 PM
Thanks for the info, Mike! I thought Zane had gone out of business. Will look them up on the web again for a close distributor, but if not here I will talk to Terradek.

S&MLL
01-26-2012, 01:18 AM
Zane is expensive. Your halfway to abt for one dimmer.
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drewguy
02-02-2012, 11:53 AM
You can use just about any normal 15 amp switch on the secondary side to control a few lights. You can also use a low voltage dimmer if you want to cut it back a little, no problem.

If they're rated 15A is it okay to use it to control more than ~180W of light?

S&MLL
02-02-2012, 02:33 PM
If they're rated 15A is it okay to use it to control more than ~180W of light?

180 would be maxed out. Spend a few extra dollars for a 20amp or mix in some LED and get that wattage down

Uniqueilluminator
02-14-2012, 06:59 PM
A few things you might want to consider.

1. Depending on how many lights you plan on switching is going to dictate what Gage wire and also what switch you will need. Its pretty simple just use ohm's law to figure out your amperage.

example: lets say you had 4 lights you wanted to switch, that would be 200 watts total. I assume you are using a 12 volt lighting system so here is the math: 200watts / 12volts= 15.4 amps.

12 gage wire is rated for 20 amps and national electrcal code states you must de-rate that to 80% so your max usable amperage would be 16 amps.
(20amps x .8 = 16amps)

Code also says that you cannot install a 15 amp rated switch on a circuit that is rated for 20amps. so if you plan on using 12 gage wire then stick with a 20 amp rated switch.

2. I am not sure what size transformer you are using and how many total watts you are loading onto it but keep in mind that ALL magnetic core transformers will drop in voltage when you load them up. So keep in mind that if you are running other lights off this transformer when you switch the lights on the voltage will go down to the other light on that unit or the opposite when you turn them off, (depending on how you want to look at it.)

GreenI.A.
02-22-2012, 09:25 PM
2. I am not sure what size transformer you are using and how many total watts you are loading onto it but keep in mind that ALL magnetic core transformers will drop in voltage when you load them up. So keep in mind that if you are running other lights off this transformer when you switch the lights on the voltage will go down to the other light on that unit or the opposite when you turn them off, (depending on how you want to look at it.)

If I am understanding you correctly- what you are saying is that if you have multiple runs coming from the transformer and one of those runs has a switch on it, the voltage will drop across all of the lights when you turn the switch on. If you turn the switch off, the voltage will increase on the other runs? Wouldn't the multitaps on the transformer prevent one run (weather switched on or off) from effecting the other main runs all together? Unless you are talking about having one run with say 6 fixtures on it and only 2 are on the secondary installed switch, in which case I fallow you.

I don't understand how a dimmer on the run would work, wouldn't dimming the line drop the voltage to levels that would prematurely ware the bulbs out. I just happened to be on Cast's sight and saw something verysimular that they pointed out. http://www.cast-lighting.com/search/1/display-document/118

NightScenes
02-22-2012, 09:54 PM
Steve, I get mine through Terradek.

NightScenes
02-22-2012, 09:57 PM
The switch effects the line that it is attached to but anytime you change the secondary load on the tranformer it does effect (very slightly) everything else on the transformer.

S&MLL
02-22-2012, 10:13 PM
Just go with something simple and has a proven track record....x10 :hammerhead:

Just kidding. Abt is the way to go. Your clients will love it. Its cheap,fantastic range and very reliable

OKSooner
02-23-2012, 12:13 PM
Just go with something simple and has a proven track record....x10 :hammerhead:

Just kidding. Abt is the way to go. Your clients will love it. Its cheap,fantastic range and very reliable

Yeah, thanks. Picked up the ABT remote yesterday and will be installing it hopefully "very soon".

Thanks to all for your input.

David Gretzmier
02-24-2012, 01:59 PM
to answer the other question above, how much your switching on/off affects voltage at other fixtures depends. I have seen nightscaping transformers drop a full volt or more by adding 100 watts to a 500 watt trans that was only running 250 "bulb watts" to start with. I would say you have little to worry about on a quality multi tap torroidial trans running less than 70% load. as you go from 70-90% load you start to see some noticable volt drop across all taps. not matter the load, if you are switching on 180 watts, you will see some drop across all taps. it is easy enought to test by switching the commons on and off while you have your circuit tester handy at the trans. The greater problem is volting all your lamps properly with the switch on and then having premature burnout if the switch is usually off.