Loaded 15A breaker - Limits?

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  #1  
Old 11-06-13, 05:10 AM
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Loaded 15A breaker - Limits?

How critical of a situation is this?

I have a loaded 15A breaker in basement. 14AWG wiring.

Washing Machine label says 10A =1200W
Currently running 7 can lights with 10W CFL's. =70
3x26W CFL overhead lights
1x20 CFL overhead lights
And there is another unused outlet available.

Im sure there is an acceptable percentage of 1800W (15A).... have I passed this? Obviously with the use of incansescents this would be pushed past the limits of the breaker already.

I know I need a dedicated line for washer, but how quickly do I have to get this done?
 
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Old 11-06-13, 05:38 AM
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If the breaker isn't tripping you have time. You may notice momentary dimming of the lights when the motor starts.
 
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Old 11-06-13, 05:52 AM
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I seem to remember learning that there is a 'continuous limit' to a circuit (a percentage less than breaker rating).... or something like that. Have I exceeded it?
 
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Old 11-06-13, 06:41 AM
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That would be 80% of rated capacity, but continuous is considered 3 or more hours.
 
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Old 11-06-13, 06:48 AM
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I would put the wash machine on it's own circuit.
 
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Old 11-06-13, 07:34 AM
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That would be 80% of rated capacity, but continuous is considered 3 or more hours.
All of the lights should probably be considered as continuous. In addition, the load is calculated using the maximum rated wattage of the fixtures, not the wattage of the installed bulbs.

Right now, with 168W of continuous load from the CFLs and the non-continuous load from the washing machine, you're not pushing the circuit's limits - 1440W for continuous and 1800W for non-continuous. (1800 - 1200 = 600 * .8 = 480 - 168 = 312W available.)
 
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Old 11-08-13, 04:43 AM
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80% is the rule of thumb, but the NEC does permit full loading
 
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Old 11-08-13, 05:28 AM
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A rule of thumb is that if the hard wired items rated wattages add up to more than half of the circuit's breakered (intermittent) wattage, those items should be in their own circuit.

Your actual usage is well below the circuit rating. You can procrastinate on adding more circuits so long as you are careful about what you plug in and when you turn each item on, so you don't trip the breaker.

When you do upgrade, don't forget that the circuit intended for the washing machine must be 20 amp (12 gauge wire) and have receptacles only in the laundry area (and no lights on it).
 
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Old 11-08-13, 09:15 AM
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80% is the rule of thumb, but the NEC does permit full loading
Just to clarify, it isn't a "rule of thumb," it's a rule. From the 2011 NEC:
210.20 Overcurrent Protection.

(A) Continuous and Noncontinuous Loads.
Where a
branch circuit supplies continuous loads or any combination
of continuous and noncontinuous loads, the rating
of the overcurrent device shall not be less than the noncontinuous
load plus 125 percent of the continuous load.
80% of the rated capacity is the maximum permitted continuous load on a circuit. Full capacity loading is permitted only for non-continuous loads.

Originally Posted by CasualJoe
continuous is considered 3 or more hours.
Originally Posted by Nashkat1
All of the lights should probably be considered as continuous. In addition, the load is calculated using the maximum rated wattage of the fixtures, not the wattage of the installed bulbs.
The calculation for a mix of continuous and noncontinuous loads can be done by subtracting the noncontinuous load(s) from the full rated capacity of the circuit, multiplying the remainder by 0.8 (80%), and subtracting the continuous loads from that, as I said earlier:
Originally Posted by Nashkat1
with 168W of continuous load from the CFLs and the noncontinuous load from the washing machine, you're not pushing the circuit's limits - 1440W for continuous and 1800W for noncontinuous. (1800 - 1200 = 600 * .8 = 480 - 168 = 312W available.)
Doing it the way the NEC suggests, we get 1800 - (1200 + (168 * 1.25)), or 1800 - (1200 + 210), or 1800 - 1410 = 390W. The difference is that the 312W is for continuous loads and the 390W is for noncontinuous loads (312 * 1.25 = 390).

I like the logic of the NEC's formula better, and I like the one I use for easier calculation. You just have to keep in mind which type of load you're getting an answer for.
[Note: Maybe I like mine better and think it's easier to use just because I'm used to it. ]
 
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Old 11-08-13, 02:29 PM
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Laundry equipment should be on their own 20 amp circuit, as required by Code.
 
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