Wire size

[Keith Nuttle]

After many years of use the cord on my Sears table saw is running out of space to wrap electrical tape around it. This is the cord from the switch not the cord from the motor to the switch. The motor is a 1 hp,

120 volt. The instruction that came with the motor says that a 20 amp fuse should be used in the circuit to which the motor is connected. (Yes I am a pack rat)

Would a cord with 12 gauge wire be sufficient for the 6 foot replacement cord, or would I use a smaller gauge wire.

I can find 14 and 16 gauge readily but 12 gauge is harder to find.

[basilisk]

12ga is rated for 20 amps

basilisk

[Lew Hodgett]

------------------------------------- Go to the electrical section of your favorite DIY and look for molded cord sets

Buy a 6'-10', 10-2 with ground (black, white, green) extension cord.

Chop off the female end and wire into saw.

Time for a beer.

Enjoy.

Lew

[Chris Friesen]

I agree with the concept, but I'd go with #12 instead of #10.

#10 is much harder to find in reasonable lengths around here, and is significantly more expensive than #12.

Chris

[Lew Hodgett]

--------------------------------------- A 1HP motor @ 120VAC?

Anything less than 10 AWG and you are kidding yourself.

-----------------------------------

----------------------------------------- A 6 ft to a 10 ft extension cord isn't readily available from your local big box store?

What part of Bum Fuck are you living in?

Lew

[Chris Friesen]

Sure. 1HP at 120 typically draws about 10A. Startup surge isn't an issue since the smaller wire can easily handle it briefly.

Both my 3HP 240V table saw and my 1.5HP 120V dust collector are fine with #12 on 20A circuits.

I'm in the Canadian prairies, but that shouldn't matter since Home Depot is pretty much the same all over. I can get a 100ft #10 cord no problem, but certainly not a 6 or 10ft #10 molded cord set.

Chris

[Keith Nuttle]

Thank you for the quick responses. I have spent the afternoon in hardware stores, and one of the big box stores but could not find what I was looking for. My plan was to do exactly what was suggested, buy a short extension cord, cut of the female end, and wire it into the switch box.

If all else fails, I will buy the cord and plug and make one myself.

At least I know I that I was right in not buying anything less than 12 gauge.

[Keith Nuttle]

Indianapolis! But we pay taxes to support the Colts and their big new expensive stadium.

[dpb]

Keith Nuttle wrote: ...

Buy the long one and a plug. Use the molded plug end for the saw section and put the store-bought plug on the remainder and you now have a nice heavy duty extension cord besides.

--

[RP]

14 ga.=3D15 amps 12 ga.=3D20 amps 10 ga.=3D30 amps 8 or 6 ga.=3D50 amps. 6 ga. for long runs (stove w/baking)

RP

[J. Clarke]

12 should be fine. If you want to use 10, look near the generators in Lowes or Home Depot. The cords will have a twist-lock connector though so you'll have to cut that off and put a regular one on, or else put in a special outlet.

[Lew Hodgett]

-----------------------------------

Think you'll find a 1 HP, 120VAC draws closer to 15A, but NBD.

Not concerned about start up inrush but rather the inrush required to handle a rapid change in power demand with a sudden change in cutting load.

(Don't try "horsing" a piece of 8/4 hard maple for instance) with a 1 HP motor.

It's a lot easier to push those electrons thru a bigger pipe.

-----------------------------------

-------------------------------------------

I can't keep up with H/D.

Last time I looked a 50 ft, 10-3, molded cord set was about $55.

Also had a 10 ft, but don't remember price.

Today I look and can't find either.

Today all I find is a 100 ft 10-3.

Go figure.

Lew

[allen476]

Go to your local electrical supply house and get 6-10' of 12/3SJ cord and a 15A 120V straight blade plug unless you have a 20A 120V straight blade on there right now. The difference is a 15A has 2 prongs parallel to each w/ground and a 20A has the 2 prongs perpendicular to each other w/ground.

The formula for ampacity when HP is known is:

HP x 746 / E x Eff x pf

Where E=3DVoltage Eff=3DEfficiency (found on plate with voltage) pf=3DPower Factor (also found on plate)

Wire size is limited by the plug. I suspect that you have a 15A plug on there now so anything beyond 12 gauge wire is a waste.

Allen

[smandel]

at shouldn't matter since Home

Appropos of not much, i was in lowes over the weekend. 100ft, 12-2 romex, 63$ 250 ft romex, 12-2, 74$ clueless!

shelly

[Doug Miller]

1HP = approx 750 watts = 6+ amps @ 120V, so that, in and of itself, is perhaps slightly unusual but hardly impossible. On top of that, you're forgetting this from the original post: "...my Sears table saw..." 1 Sears HP = approx 0.3 real HP, so even allowing for inefficiency, it's unlikely that it pulls any more than 3A.

Don't be silly. 10AWG is rated for 30A, which at 120V = 3600W = a bit less than 5HP. There's absolutely no need for even 12ga, let alone 10ga, for any

1HP motor at 120V -- especially a Sears "1HP" motor. A 14ga power cord is quite sufficient.

[Martin H. Eastburn]

[keithw86]

Remember the starting current.

If it's a real table saw, with an induction motor, the 1HP rating is probably good. If it's one of the table top toys with the universal motor it would probably be rated at six or ten horsepower.

I'd go with 12GA anyway, just because. Both 12GA and 14GA SJ cable are readily available at the big box stores. 12GA SJ should be something just over a buck a foot.

[Keith Nuttle]

Original Poster: The motor is a Sears 1 hp motor that came with the

10" table saw when it was purchased in 1969. It is a capacitor start motor which for the first couple of microseconds draws a quite high current.

[Doug Miller]

Remember the brand name. If Sears claims it's a 1HP motor, you can depend on it that it's no more than 1/2 HP.

Sears is notorious for overstating their motor ratings.

Well, there's no harm in using 12ga (except to the wallet), but it's not needed for a motor that small. And 10ga is just silly.

[Doug Miller]

Again: if Sears says it's 1HP, it's probably really no more than 1/2 HP.

In any event, even if it's really 1HP, 14ga is enough to handle the load. The inrush current is of a short enough duration to not be a problem.