Recent content by psparky

Thanks guys, I read the wikepedia article and I get the jist of what you are saying overall. I can see the graph above is on logarithmic paper rather than lineal. My point in general is that if you are standing next to a wide open energized 480 panel (with the face plate removed)...you should...

Also, people argue if its the volts or amps that kill you in electrocution as far as burning. Sure its a combination of the two, but I believe its the WATTS that kill you. Isn't WATTS a measure meant of work being done? Isn't 100 watts four times the work as 25 watts? Isn't 4 HP four times...

Interesting stuff. Can we all agree with this statement? "Voltage gain squared equals power gain when using the same resistance" In other words, let's say we have a 6 ohm heater and I hook it to 120 volts. We get 20 amps at 2400 watts. Now let's take that same 6 ohm heater and I hook it to...

Hey guys, I need confirmation on this. Since V=IR and P=IV...and V^2/R=P Lets say your body has a resistance of 2000 ohms and you get shocked by 120 volts. You receive 7.2 watts of power. Now let's step to the left and get shocked by 480 volts with the same 2000 ohm body. I now get 115.2 watts...

The neutral of the secondary is grounded just like the neutral is grounded in a house panel. The only thing going thru here is perhaps a small trickle current, a perhaps a ground fault or things of that nature. When the secondary of transformer gets disconnected, the primary sees an open...

Try here: http://ppi2pass.com/?gclid=CPz2h9P10MYCFQMbaQodMrQHwA These are the books used to study for the PE and FE. Look up the "power" portion of the books. Should be thousands of examples with solved solutions. This link specifically has the power books. You may be able to get these...

Perhaps a transformer before your main panel could solve all your problems? Use a voltage based on 5/6 or 6/5 the intended voltage depending on your application. This way you can keep the current at least close to its original specs.

The 50 to 60 hertz is actually a big deal. Anytime u change the current in a motor, good things do NOT happen.

It's hard to give advice on this subject because we don't know exactly what you have. It's possible you will need a neutral for a possible 110 volt circuit involved. Like usually the clock and controls on the oven for example. At first I thought you were talking about a single load, but now...

Wiring two 110 legs that are 180 degrees out of phase is simply 220 volts that is actually called "line to line" This would need to be run off a 2 pole breaker. If you wire two 110 legs that are on the same phase, you will simply have 110 volts with twice the available amperage which will not...

This sounds like nonsense. Setting the capacitor voltage to 7 volts in the formula is good. What is said above probably isn't going to do you any favors. You don't care when it's charged, you just care when it's 7 volts.

Yep, that is correct. Solve for t. ln .5 = -t/(1.7E-3) t = 1.18 ms.

Just talked to my mechanical guy...that is exactly why they had to use a 10 ton unit instead of a 7 ton. Also, the fan doesn't quite make the 4000 CFM mark they are looking for so they are going to change the pulleys a bit to make it more like 60 hz...I suppose that will put the fan amps closer...

Thanks Jim. Ya, that is interesting. I think your guess about moving less refrigerant sounds reasonable. I'll report back when I more info. Here's where things get fun. I need to issue this for construction. But I am waiting on a rep. Do I delay the job?...or do I issue job with our...

Actually, it was going to be a 7 ton unit, but they changed it to a 10 ton...the mechanical guy said the 10 ton was "de-rated". 2 compressors running at 7.8 amps (RLA) a piece and one fan running at 4.2 amps (FLA). That is the specs for the unit when it is hooked up to a 460/3/60 source. With a...