Router Horse Power

[ron brown]

Reciently I posted about needing bearings for a 6902 Porter-Cable Router. It was replaced with a PC690. The nameplate claims "11 Amp" and "1 3/4 HP". Where I am we have a device to measure amps and volts.

Actual measured power use is 4.5 amps with a 10mm cut ~10 mm depth using a new edge on a 5/8" (16mm ) Her-Saf bit. Maximum pull measured was 7 Amps with a 12mm X ~10mm cut.

These numbers indicate .71 to 1.11 HP. I feel sure Porter-Cable would never lie about thier ratings. Quite possiblly they may have discovered the secret of perpetaul motion and have just not published the results.

Ron

PS: My 7518 Porter-Cable only draws 1000 watts at peak draw (1000/746 = ~1 1/3 HP) or so and makes 3 3/4 HP! I am proud to see American industries on the forefront of electrical production, utilization and efficiency.

[gerald_d]

Ron, you were measuring RMS (Root Mean Squared) power, while their nameplate indicates Peak power.

With AC (Alternating Current) electricity, they claim that their router can handle 11 amp peaks in the alternating current. You have measured the "averaged" (mean) current draw which is a factor of 1.414 less for sine-wave shaped AC. The square root of 2 is 1.414

Here (http://www.talkshopbot.com/forum/cgi-bin/discus/show.cgi?tpc=29&post=13704#POST13704) is an old post on this subject.

Routers in the metric world (conforming to Europe and Japan standards) give the RMS values on their nameplates.