Home Electricity and Amperage

Your math is correct. What you do not know is the load in the other apartment. When you plug something in it could be taking the circuit over the max rating. Once breakers start tripping sometimes they can get weak. Replacing them can help. I suggest that you check all of the connections in the panel, and your outlets. If anything is loose that could hurt you a little as well. My college dorm was wired the same way. (1969) We reset breakers all of the time. We were not allowed to have refrigerators because of the problem. I refused to go back to that dorm the second year, as well as 1000 of my dorm mates. The U finally rewired the rooms at a huge cost.

I would like to add that this 100 watt halogen bulb generaes much more heat than a standard 100 watt bulb in a regular lamp socket. This further causes me to wonder if more energy is being pulled since both the light output and heat output are higher.

Now a device rated at 1500w, 1500w is the PEAK power rating; it might be less but you should assume 1500w.

When your breaker trips, there may be other loads on the circuit that cause it to approach the tripping threshold, whereas the other circuit may not have these loads.

Beachcomber

In electronics, various devices have values and manufacturing "tolerances". Say a device has a stated value of 100 and a tolerance of 5%. That means that the value is 100 - plus or minus 5%.

Basically it is difficult and more expensive to manufacture electronic parts which have an exact value. So products which state 1000 watts would vary a little bit even for the same exact model and manufacturer.

Note that some electronic parts vary by 20%...

Don't confuse "heat" and "temperature". A halogen is hotter but that is spread out over a smaller lamp envelope so the heat is more concentrated. Total heat output is still around 340 BTU from a 100w bulb, halogen or not. The only thing that will affect simple watts = amps x volts formula, is power factor. The power factor of a light bulb or space heater is pretty much 1 so it isn't a factor. In motors and power supplies you can see a bit of power factor correction needed. For the layman, the difference in load on a motor or a power supply will usually be more than the power factor correction. If you call a HP

Sounds like SQ has it...bad connections...the lamp or device that flickers or acts up occasionally would be the bad outlet...As far as the vacuum goes...the current draw on it varies according to load...so if you close off the vacuum...the motor works harder and thus draws more current...Perhaps, when you vacuum, you could open up the draft (assuming it has one). It might not pick up as well but then it may not trip the breaker..

In misc.industry.utilities.electric Jaxon Bridge wrote: | |> For example I have a consumer halogen floor lamp in which I use 100 watt |> halogen bulbs. I usually live in places with weak circuitry, and having |> this light on at the same time as a vaacuum cleaner, for example, will |> blow the circuit. But it's only 100 watts! | | I would like to add that this 100 watt halogen bulb generaes much more | heat than a standard 100 watt bulb in a regular lamp socket. This | further causes me to wonder if more energy is being pulled since both | the light output and heat output are higher.

The halogen bulbs in those lamps get much hotter than regular bulbs in part due to the construction and small size. They are better able to withstand the temperature. The filament also runs hotter for greater efficiency (less IR and more light, higher color temperators).

Is it genuinely operating at 100 watts? Get an ohm meter and measure its resistance and see what it really has. Be very careful not to get any skin oil on the bulb as that could cause it to burst when it gets hot, again.

You may have other problems on the circuit that cause the breaker to open when you combine the bulb with the vacuum cleaner. You may have a loose or open neutral wire. Or there may be some ground current tripping a ground fault interruptor that could be in your breaker, or in another outlet wired cascaded to the one your using. Turn off your main breaker first, then turn all the other breakers off, then turn on 1 breaker feeding ONLY a lamp. Now turn the main back on and see if it lights. If no or abnormal, you have a problem. Turn on another breaker on the OTHER phase, also with only a lamp, and see if the first one changes brightness. It should not. If there is any indication of a problem, leave everything off and call an electrician to check for a bad neutral.

You have that backward. A vacuum actually drwas less current when it is blocked because it is air starved and it is actually doing less work. Hook up a clamp on and test that if you don't believe me but you do notice the motor is actually running faster? As another gee whiz factoid, when I connected my clamp on to my new air compressor I noticed it has the same power curve. (1 hp motor @120) When the tank is empty the current is around 12a. at 100 PSI it peaks a tad over 15a and at 150 PSI it has dropped back to the 12a range.

Gregg, I stand corrected...I just assumed that the motor was working harder and drew more current. I just ran a test on my trusty old Eureka Might Mite and it drew 7.5 amps unrestricted and 5.8 restricted....so my humble appologies on this one.....

I had to try it to believe it too. It sure doesn't sound right. The one that really shocked me was the compressor.

.> I just ran a test on my trusty old Eureka Might Mite

The bulb's resistance will change as it heats. It won't get hot when connected to the ohmmeter, so the meter reading will not show the bulb's operating resistance.

When you start a vacuum cleaner, it draws about 5 times its normal running current for an instant. This would trip out a circuit breaker or fuse on a circuit that was already close to capacity. A heating unit, starting cold, will draw more current until the coils get hot, just like a light bulb.

I too was surprised because anytime you add load to a motor or mechanically reduce its speed, it draws more current.....apparently not the case with the vacuum cleaner.

When the vacuum becomes air starved it is moving less air actually seeing less load.