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BAnderson · Sep 5, 2007, 03:09 PM

I would like to install one of those cool in wall programmable timer/switch but have a question. The switch I would like to replace controls 2-500watt halogen lights, 2-150watt incandescent flood bulbs, 60watt outside door light, and finally 2-150watt halogen lights which totals up to 1660watts.

With that said I need a timer/switch that can obviously handle 1800 max watts, so Im looking at this Intermatic timer here: Intermatic Timers - Consumer Indoor Timers - In-Wall Timers - SS7C

What is confusing the hell out of me is that it doesn't list the max watts but instead this:

Resistive Heater 15 Amp 120-277 VAC
Tungsten Incandescent 15 Amp 120 VAC
6 Amp 208-277 VAC
Ballast Fluorescent 8 Amp 120 VAC
4 Amp 208-277 VAC
Motors 1HP 120 VAC
2 HP 240 VAC
DC Loads 4 Amp 12 VDC
2 Amp 28 VDC

So with this info Im taking this as this will handle a full 15amps based on the Tungsten Incandescent 15 Amp 120 VAC rating but Im not sure and really don't want to waste $50-$70 on this timer if it will not work.

Any info will be GREATLY appreciated as well as maybe other suggestions although I would really like to stick with one of these cool in wall timer/switches :D

KISS · Sep 5, 2007, 04:22 PM

Power(W) = voltage(V) * amps(I)
1800 watts =120 * 15

So, your at the max. OK

BAnderson · Sep 5, 2007, 05:31 PM

Originally Posted by KeepItSimpleStupid

Power(W) = voltage(V) * amps(I)
1800 watts =120 * 15

So, your at the max. OK

Not sure if I follow you? I understand the whole 15amp circuit=1800 watts what Im needing to know is if this particular intermatic wall timer/switch that I listed above will be able to handle a load of 1800 watts max?:confused:

Tungsten Incandescent 15 Amp 120 VAC<--------This is what is confusing me, does this mean what your saying? If I am reading this right its saying 15 amp 120 VAC which as you stated would be 120*15 to give 1800 watts. I guess I just need someone to let me know if Im reading this right?

Thanks

KISS · Sep 5, 2007, 07:24 PM

Normal light bulbs are tungsten.
Halogen lamps are actually tungsten-halogen.
So you use the tungsten rating of 15 AMPS

The 15 amp rating * the voltage = 1800W
re-iterating: Timer will handle 1800W tungsten

1660<1800 so your within the rating of the timer.

If P=VI then I=P/V; Your circuit will draw 1660/120 or 13.8 amps

which is only an 8.4% safety factor assuming a 15 AMP breaker in the fuse box.

Variations an manufacturing and the lamps and line voltage COULD cause nucense trips, but if you are already using these, then a 15A circuit will be OK.

Ratings are not an exact science. It won't die at 1801 watts.

Aside: Tungsten filaments typically draw about 10x their current for a short time at startup.

Better?

BAnderson · Sep 6, 2007, 01:01 PM

Originally Posted by KeepItSimpleStupid

Normal light bulbs are tungsten.
Halogen lamps are actually tungsten-halogen.
So you use the tungsten rating of 15 AMPS

The 15 amp rating * the voltage = 1800W
re-iterating: Timer will handle 1800W tungsten

1660<1800 so your within the rating of the timer.

If P=VI then I=P/V; Your circuit will draw 1660/120 or 13.8 amps

which is only an 8.4% safety factor assuming a 15 AMP breaker in the fuse box.

Variations an manufacturing and the lamps and line voltage COULD cause nucense trips, but if you are already using these, then a 15A circuit will be OK.

Ratings are not an exact science. It won't die at 1801 watts.

Aside: Tungsten filaments typically draw about 10x their current for a short time at startup.

Better?

:D Thanks for the help. After I saw the web site and saw this: Tungsten Incandescent 15 Amp 120 VAC--I was pretty sure it would handle 1800watts but when I called one of the local supply shops to see if they had it in stock I also asked how many watts it could handle and he said 500 but he may have looked at the other model, but ever since then I was just uncertain and since it never came right out and said xxx watts I just wanted to cover my rear before I cause something to happen that could have been prevented. Thanks so much for the info I can relax now :)