Low volt lighting

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knot stable

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Warren,RI
It's been a while so please bear with me. I have 120 volt track lighting and customer wants to install low voltage heads (MR16). I want to make sure I do not overload the track. The lamps are 50w each. Do I us the lamp wattage and the line voltage for calculating or do I use the low (12V) for my calculations? I got 20 ft of track and want 15 heads (lo Volt MR16)
 

infinity

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15-50w, 12v heads should be fine on a 15 amp circuit. Without transformer losses your 120 volt current would be about 6.25 amps.

Someone can check my math:

15 * 50 = 750/12= 62.5
62.5/10 = 6.25 amps
 

Dennis Alwon

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You do realize that most LV dimmers are rated 300 watts or 600 watts depending if they are electronic or magnetic transformers. Watts are watts so except for the power factor of the transformer you will have 750 watts.
 

maghazadeh

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Location
Campbell CA
15 * 50 = 750/12= 62.5
62.5/10 = 6.25 amps

knot stable
Where did the # 10 come from?

15 * 50W = 750W/12 = 62.5A @ 12V
750W/120V = 6.25A @ 120V
Here is where # 10 came from 120 / 12 =10

Most 120V track with low voltage heads that the transformer is on the head will work with line voltage dimmers, unless it is electronic transformer. You need to double check that.
 

Howard Burger

Senior Member
xf per light, or one xf a ways away?

xf per light, or one xf a ways away?

KS - does each MR16 light have it's own transformer or is the transformer a distance away from where the track is to be mounted?
 
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iMuse97

Senior Member
Location
Chicagoland
Well, duh. Thanks, stickboy. I guess my eyes went faster than my mind. 120v track. OK.

I still think your question needs to be answered. I'm not clear from the OP that there are XFMRs on the heads. All that is said is that the existing track is 120V. But assuming the head itself has the XFMR, the track will not be overloaded, at 6.25A as others have mentioned. If the track is now being re-purposed as a low-voltage track on the load side of a XFMR, then it will be overloaded to the tune of < 3x.
 
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infinity

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I have 120 volt track lighting and customer wants to install low voltage heads (MR16). I want to make sure I do not overload the track. The lamps are 50w each. I got 20 ft of track and want 15 heads (lo Volt MR16)

Sounds like a 120 volt supplied track with 12 v heads with integral transformers.
 

Dennis Alwon

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Chapel Hill, NC
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Retired Electrical Contractor
15 * 50W = 750W/12 = 62.5A @ 12V
750W/120V = 6.25A @ 120V
Here is where # 10 came from 120 / 12 =10

Most 120V track with low voltage heads that the transformer is on the head will work with line voltage dimmers, unless it is electronic transformer. You need to double check that.

Most track heads are electronic and why would magnetic make a difference. I know it will work on some but they make LV dimmers that are magnetic & electronic. The fact that the track is 120V has nothing to do with it.
 

knot stable

Member
Location
Warren,RI
Yes it's 120volt track with lo volt heads with transformer on heads. Ok so the bottom line is I am not going to overload the track with 15 50 watt lo volt heads on this track. Thanks for the input, when I have not done something in a while I need a little shaking to bring me back around.

Dave
 
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