Shopsmith Forums

paulsgreenbarn wrote:Well I took it for a test drive today.I needed some 3/4" dadoes for this Hutch I'm working on so set it up.First lesson: you can't just hog out 3/4" X3/8"deep dado in one pass.Surprise right?Lesson #2: The previous owner had it wire for 220 for a reason.The 110 setup shut down during the project due to too much heat.Lesson #3: Slow down! Turned the speedchanger back to #3 and it allowed the motor to operate alot cooler without shutdown.I proceded to make two 3/16" passes on each piece and things worked better.Lesson #4: Remember you're working with 50 yr.old technology.These were designed to be mor efficient than doing it by hand.They aren't today's woodworking machines by any means.
all in all ,lots of fun.

I do not understand how 110 would create more heat than 220.

The motor is 3/4 hp(or maybe 1/2) so 3/4 x 3/8 is indeed aggressive. I would not try that with a Mx. Blades sharp?

Are you running it with a long(or too small) cord. Then I could understand the heat @ 110(the motor is running starved for voltage).

I assume the speed changer was on the high speed setup.

JPG40504 wrote:I do not understand how 110 would create more heat than 220.

Maybe I'm showing my ignorance here but, 110 draws more current than 220, and current equals heat. Right?

Actually, Power(watts) is the product of voltage(volts) x current(amps).

It is typically assumed that if you change a motor from 110vac to 220vac, it will draw 1/2 the amount of current.

110vac x 10amps = 1100 watts while 220vac x 5 amps = 1100 watts

I agree with you, charlese and if you are ignorant so am I.

charlese wrote:Maybe I'm showing my ignorance here but, 110 draws more current than 220, and current equals heat. Right?

Yes, more current will be drawn through the 110V power cord, and the power cord itself will get warmer as a result. But unless the cord is undersized or defective, only a very small percentage of the heat loss will be in the power cord.

Now for the motor itself. A dual-voltage motor has two windings. To run the motor on 110V, the windings are connected in parallel. To run it on 220V, they are connected in series.

To use Dusty's example, let's say that the motor draws 5A at 220V. The windings are connected in series, so each winding carries the very same 5A current.

Now, consider the case where the motor draws 10A at 110V. Because there are two identical windings now connected in parallel, each winding draws 1/2 of the total current, which is again 5A per winding.

Indeed, in either case, each of the windings sees a total of 110V at 5A. Thus the per-winding power is the same in each case. And since there is always a total of two windings, the total power is the same as well.

Hey Paul, after writing that last post, I went and checked the ratings plate on my 10ER motor. It is a single-voltage, 110V motor. Any chance that you were trying to run a 220V-only motor on 110V?

Thanks guys for your input.The motor is definitely able to run on 110 and 220.It may be more a case of a too light of a cord.The guy installed a very long lightweight cord.Probably a 16 gauge by the looks of it.i'll replace it witha short 12 gauge cord and see how it works.I might just hook it up to 220 again and use a 10/3 cord.I'm sure it's nothing major.The 3/4 hp should handle a 6" dado blade .
I'm no expert but I've always heard that 220 is the way to go whenever possible.Cheaper to run the machine than 110 too.

paulsgreenbarn wrote:Thanks guys for your input.The motor is definitely able to run on 110 and 220.It may be more a case of a too light of a cord.The guy installed a very long lightweight cord.Probably a 16 gauge by the looks of it.i'll replace it witha short 12 gauge cord and see how it works.I might just hook it up to 220 again and use a 10/3 cord.I'm sure it's nothing major.The 3/4 hp should handle a 6" dado blade .
I'm no expert but I've always heard that 220 is the way to go whenever possible.Cheaper to run the machine than 110 too.

220 is indeed 'the way to go'.

Reason being the current in the supply wires is half that at 110.

So the voltage drop in the supply wiring will be half and the motor will have more voltage to run on. Motors do not like running on low voltage(they get hot trying;)).



Do replace the cord. 12 ga is sufficient for 'reasonable' length.

Cheaper? Only because power loss in the wires is less. Not a biggie unless wires are too small and motor is using power to heat the room!:rolleyes:

Why do y'all think power distribution is done at very high voltages.

JPG40504 wrote:
Why do y'all think power distribution is done at very high voltages.

Because there are a lot of us out here using it. Drop a little here and drop a little there and the next thing you know there is none left to drop.

Ok,As long as we're talking ER's;My two have the serials#s of ER 19469 for thew one without the speedchanger and ER38817 for the one with the speed changer.Anyone care to offer an educated guess as to their year of manufacture?

Hi,

From my listing I see #19102 listed as March 1950 so yours has to be very close to that. The 38817 would be later that same year or possibly early 1951.

Ed

[quote="paulsgreenbarn"]Ok,As long as we're talking ER's]