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-   -   Why does my radial arm saw keep tripping the breaker? (

djtjak43 04-14-2009 05:02 PM

Why does my radial arm saw keep tripping the breaker?
My radial arm saw (11 amp motor) often trips the circuit breaker(15 amps)
Any thoughts why?

Yoyizit 04-14-2009 05:21 PM

We had this problem already. The "often" is the key. Half the time the saw will be turned on at the peak of the AC waveform.

As a test, put the saw at the end of a small gauge extension cord. You're adding series resistance to the circuit.

There is also a table of allowable extension cord lengths vs. allowable gauge numbers in your saw manual. #10 is 2 milliohms/ft, #12 is 3.2, #14 is 5.2.
See the table halfway down the link

Another way that should work to reduce this problem is to spin the saw blade [careful] in the correct direction before turning on the motor.

Chemist1961 04-14-2009 06:24 PM

High output electric motors often draw more than their amperage rating on startup, also known as "in rush".
In the central vac industry in the late 90's this caused several years of turmoil as there were numerous underated relays burning out, a problem caused by new higher rpm motors, high output motors being used due to increased home sizes.
Add in rush to an extension cord or another device on the line and there goes your breaker....

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