It is a universal physical law that 1 HP is equal to 746
	watts.  Given heating loss, power factor and other inefficiencies,
	it is usually best to consider 1 HP is going to need 1000-1200
	watts.  A 110V 15A circuit can only deliver 1850 watts to a motor,
	so it cannot possibly be more than approximately 2 HP.  Given rational
	efficiency factors, 1.5HP is more like it.

	Some equipment manufacturers (Sears in particular, most router
	manufacturers in general ;-) advertise a HP rating that is far
	in excess of what is possible.  They are giving you a "stall
	horsepower" or similar.  That means the power is measured when
	the motor is just about to stop turning because of the load.
	What they don't mention is that if you kept it in that
	condition for more than a few seconds your motor will melt - the
	motor is drawing far more current than its continuous rating.

	When comparing motors, compare the continuous horsepower.  This
	should be on the motor nameplate.  If you can't find that figure,
	check the amperage rating, which is always present.


User Contributions:
Dev
Dec 21, 2011 @ 12:00 am
In a fire protection circuit, circuts are shown witha no example 6,8,4etc. what it mean?these circuits are connected between smode detector,junction box etc
kevin
Dec 24, 2011 @ 12:12 pm
My daughter dropped a small necklace behind her dresser. The necklace crossed a plug terminal and shorted the receptacle.

I bought a new receptacle and installed the same. I still have no power  I suspect there could be a bigger problem,this is aluminum wiring.

I've killed the breaker and call an electrician but am curious as to what happened.P.s. there is a dimmer switch on the same circuit.
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