# Wiring multiple lights off of an existing light??



## Scuba_Dave (Jan 16, 2009)

Do you know what else is on the circuit?
Are the existing lights turned off & on by a switch?
Do you have access from above to run the wires?
Or will you be fishing them thru the ceiling?
It can be done, depends upon exisiting wiring

But basically you just run wire from one to the next


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## n00b (Jun 21, 2009)

Basically all the lighting on the middle level of my townhouse are on this same circuit. 

There is one switch that that controls the two existing lights.

I will have to fish the wires through the ceiling but I don't see this as being a problem because the new lights will only be separated by a few feet.

Thanks for the quick response scuba_dave...


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## Scuba_Dave (Jan 16, 2009)

Do you know if the power feed is to the light 1st or the switch?
This will determine wiring method
What colored wires at the lights?

You need to calculate the load on the circuit
If it is all lighting then you can exceed the breaker limit for all lights on that circuit
IE if a bulb fixture indicates 100w bulb Max that is what you use
If the recessed cans indicate 75w max then you are adding 6*75 = 450w to that circuit
15a circuit = 1800w Mac
20a circuit = 2400w Max


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## Scuba_Dave (Jan 16, 2009)

Wire gauge on 15a circuit = 14 gauge, 20a = 12 gauge
Example of wiring


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## PaliBob (Jun 11, 2008)

If the existing fluorescent fixtures are surface mounted, recessed lights can be installed using remodel cans which are installed from below. Please supply more info.

Besides Commercial we can help with DIY tips on Installing Recessed Lighting


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## Scuba_Dave (Jan 16, 2009)

Circuit wiring direct to light
Switch only interupts the hot feed
White has been re "coded" as black


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## n00b (Jun 21, 2009)

I don't know if the power is fed to the light or the switch first.

One of the fixtures has a white, black, & ground wire.
The other fixture has the same setup only times two; i.e. 2 black, 2 white, & 2 ground wires.

How do I know if I have a 15a or 20a circuit?

Also, the fluorescent lights are surface mounted.

Thanks again...appreciate the diagrams.


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## J. V. (Jun 1, 2007)

Just add up the wattage of the new fixtures. Watts divided by volts gives you the total current. Use the maximum allowed for the fixture for calculating. Let us know the total wattage. Yes, It's that simple.

Do not concern yourself with how the switches are wired, unless you want to change how the switches work. Connect the new fixtures just like the old fixtures. Just run the cable from the existing to the new.
Make a drawing so you can put it back like it is now. The connections.

Check the breaker that turns the lights on and off for circuit size.

I have no idea how switches got into this thread. The OP only asked if he could add lights to an existing circuit. Please, lets not confuse him. Stay on topic and just answer the damn question.

If he needs a new home run than we can address that after he tells us the total wattage. And what size breaker he has. :whistling2:


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## n00b (Jun 21, 2009)

The new fixtures are 50 watts max each. Total is 300 watts. 

Right now the four current fluorescent bulbs are 40 watts each for a total of 160 watts. So I'd already be over by about 140 watts once the new fixtures are installed. 

Thanks...

EDIT: It's a 15a circuit


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## J. V. (Jun 1, 2007)

It will work on a 15 or 20 amp circuit with plenty room to spare. Just install the fixtures and connect them to the same wires the old ones are on. The total current draw is 2.5 amps. However, this is just for the lights. What else is on the same circuit?


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## Scuba_Dave (Jan 16, 2009)

Switches matter because he needs to be aware of how things are wired. Many people take it apart & thenhave no clue how to put it back together. Its also important to know where the power is coming from

And if the circuit is already maxed out with the existing lights then even adding "only" another 140w is against code. It's that simple

One the points of DIY is learning & learning how to do it right

Don't be such a damn ass


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## n00b (Jun 21, 2009)

I just added everything up. Currently there are 1060 watts on the circuit plus one outlet and one exhaust fan. The outlet has a 60 watt lamp hooked up to it and various entertainment media (i.e. tv, dvd player, cable box, ps3, wii). How many watts do the outlet and exhaust fan draw?

Like I said, adding the new lights will add an additional 140 watts to the circuit. Will I overload the circuit?

Also, it looks like one of the current fluorescent fixtures is in the middle of the circuit because two sheathed cables are entering the box. Howdoes this change my wiring scenario?

Thanks.


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## J. V. (Jun 1, 2007)

Scuba_Dave said:


> Switches matter because he needs to be aware of how things are wired. Many people take it apart & thenhave no clue how to put it back together. Its also important to know where the power is coming from
> 
> And if the circuit is already maxed out with the existing lights then even adding "only" another 140w is against code. It's that simple
> 
> ...


Dave, I will not get into a pissing match with you. He does not need to be aware of how things are wired. He's not an electrician. Are you?
All he needs to know is if and how he can accomplish his project. If you want to get complicated try one of the professional boards where they will eat you alive. This is a DIY forum.


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## Scuba_Dave (Jan 16, 2009)

I'm not an electrician & I do need to know how things are wired
I've seen too many people who are told to simply replace it/wire same as it is & then come back & say it isn't working
Then its 2x as hard to figure out what they did wrong


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## n00b (Jun 21, 2009)

Hey guys, I posted the total wattage a few posts up; 1060 on a 15a circuit. Not sure how much wattage to add for the outlet and exhaust fan on the same circuit.

Do I need to do aything different since one of the fluorescent lights is in the middle of the circuit? i.e. it has two sheathed cables running to the box.

Thanks for all of the help. I am actually learning a few things...


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## Scuba_Dave (Jan 16, 2009)

Do you know how many watts/amps the fan takes?
Is it an over the stove exhaust fan, bathroom exhaust fan?
Is the 1060 the actual watts in use or do you use CFL's bulbs?

Does that include the existing 160w of lights?

1060
..300 new lights
...60 bulb
************
1420 out of 1800 so far (maybe)
That doesn't leave much extra wattage for items plugged into the outlet

Do you know how much your TV & other electronics (on that circuit) that are normally turned on draw?

Has the breaker ever kicked off?
I'd hate to see you add the 140w & then have the breaker kicking off


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## n00b (Jun 21, 2009)

Not sure of the wattage on the fan...but it is a bathroom exhaust fan.

1060 is the actual watts in use. No CFL bulbs.

As of right now, I have a total of 1060 watts which includes everything except for the outlet, and exhaust fan.

I found that the tv draws 226 watts and I have a 60 watt lamp plugged into the outlet as well. Thats adds 286 watts bringing the total up to 1346 watts plus whatever wattage the fan is. 

Sounds like I should be ok to add another couple hundred watts right? I never have all the lights on anyway and the breaker has never kicked off.


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## Scuba_Dave (Jan 16, 2009)

I'd say you should be OK

1060 now
..140 increase
...60w lamp
..226w TV (inlcudes cable box?)
..100w fan (maybe) - newer use down to 15-45w
*************
That's 1586 with everything on

Some older fans (and some newer) can use over 100w
If the breaker kicks out I'd install some CFL bulbs to lower your use
About 90% of my lights are now CFL. Some of the bulbs were free after instant rebate at Home Depot. I installed (4) CFL fixtures in my kitchen that each use 13w.
If you have a 100w bulb installed a CFL equiv only uses 23w
60w equiv around 13w, 40w equiv = 9w
For most of my areas I buy the Daylight bulbs - much whiter light

Did you already purchase the recessed fixtures?


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## n00b (Jun 21, 2009)

No, I have not purchased the fixtures yet. 

One last question though. Your diagrams were very helpful but how do I wire the the three that I am installing in place of the fluorescent fixture that has the two sheathed cables running into the box (2 black, 2 white, and 2 ground wires)? Does this make sense?

Thanks for the info on the CFL bulbs, didnt realize they reduced the wattage by so much.


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## Scuba_Dave (Jan 16, 2009)

So basically the 2 wire setup is the same as the 1st light on the left in this diagram? 1 wire coming in, 1 wire going out to the next light? Then the wires to the actual light?
In its simplest form, turn off the power, disconnect the black, white & ground of the existing light, then attach the black, white & ground of the new light. Do the fixtures have a recessed box where all the connections are made? Or are the wires connected together inside the fixture?
The new recessed fixtures will come with a small attached box where all the connections are made. You may need to buy clamps, I buy the ones that allow 2 wires under the clamp










Wire gauge on 15a circuit = 14 gauge - so you will be using 14g wire Example of wiring








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## Scuba_Dave (Jan 16, 2009)

Where you run the wiring (to the next fixture) depends upon the layout


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## n00b (Jun 21, 2009)

I'm going to be running the wiring side-by-side inside the ceiling; they will be in a row like in your diagram above.

I don't have the fixtures picked out yet. I'll probably be attempting this next weekend. I appreciate all the help.


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