Shopsmith Forums

I know this has turned into a discussion on safety features, but I did some research on the technology a few weeks ago and my impression was that the advantage of the PowerPro inverter was "Smart" power control, saving energy and smoother operation. In an industrial environment that is a huge deal. Have you guys ever seen a quarter million dollar electric bill for the month? I have. Ever seen an OSHA recordable because of excessive kickback? I have. And the biggest demand was from electric motors, worst of all being air compressors that fed the entire plant.

So my opinion is that the PowerPro inverter exists because the large scale savings made it feasible to develop the technology, and for the at home guy you get a smoother, higher quality machine and a few dollars off your electric bill.

frank81 wrote:I know this has turned into a discussion on safety features, but I did some research on the technology a few weeks ago and my impression was that the advantage of the PowerPro inverter was "Smart" power control, saving energy and smoother operation. In an industrial environment that is a huge deal. Have you guys ever seen a quarter million dollar electric bill for the month? I have. Ever seen an OSHA recordable because of excessive kickback? I have. And the biggest demand was from electric motors, worst of all being air compressors that fed the entire plant.

So my opinion is that the PowerPro inverter exists because the large scale savings made it feasible to develop the technology, and for the at home guy you get a smoother, higher quality machine and a few dollars off your electric bill.

The 'inverter' is a power supply for the 'controller'.

I totally agree with everything else said!

However constant load devices like a compressor would not likely gain much from DVR technology. They could I believe reduce startup current surges.

JPG40504 wrote:The 'inverter' is a power supply for the 'controller'.

I totally agree with everything else said!

However constant load devices like a compressor would not likely gain much from DVR technology. They could I believe reduce startup current surges.

The startup loads were the costly part when you're classified as heavy industrial and paying half price useage but full price for peak demand charge. Turn all three compressors on at once for 5 minutes and you just spent $40k.

frank81 wrote:The startup loads were the costly part when you're classified as heavy industrial and paying half price useage but full price for peak demand charge. Turn all three compressors on at once for 5 minutes and you just spent $40k.

I think it would be worthwhile to interlock them and prevent simultaneous startup. At 8k/min it might be worth the effort.

I have no idea how far separated they are but I imagine a considerable distance!

Surely you have other 'major' loads as well.

P.S. I am sure the compressor motors are much larger than 2 hp!

[quote="JPG40504"]I think it would be worthwhile to interlock them and prevent simultaneous startup. At 8k/min it might be worth the effort.

I have no idea how far separated they are but I imagine a considerable distance!

Surely you have other 'major' loads as well.]

Yes, those compressors were impressive. I don't remember the exact hp but 3 of them were supplying compressed air piped throughout the complex...close to 2m sq feet. IIRC the smallest one was around 50hp, at one time I had worked out what the theoretical startup draw was in kW to prove out how costly it was but don't have the workpapers any more. That was the prior plant I was at so someone else's problem now!

charlese wrote:Lately I had the message on the PowerPro panel that says "High Inverter Heat"

That got me to thinking (dangerous all by itself).

My meager Knowledge of electronics tells me an Inverter is to increase voltage. I learned that much from inverters in Motor homes. They use battery power (12VDC) to 115VAC in order to run household electrical stuff.

Now my long question - Since the PP runs on 115 or 220VAC What does the inverter increase voltage to? Is part of the PP run on 330V or 440V?

Maybe one of the electronic guys on the forum can tell me if my assessment of an inverter is correct. and make a guess of its purpose.

Hi Bill, An inverter changes DC to Modulated AC, thus the ability to have a variable speed...It changes the frequency to vary the speed..The higher the frequency, the faster it goes.. The power is steady because the pulses are full amplitude..That is the short version of it!!!!

sawdust2155 wrote:Hi Bill, An inverter changes DC to Modulated AC, thus the ability to have a variable speed...It changes the frequency to vary the speed..The higher the frequency, the faster it goes.. The power is steady because the pulses are full amplitude..That is the short version of it!!!!

I am refraining commenting.