I am with you. I never read them unless I get stuck.
We started putting inrush limiters on our power products when some bigger amps began tripping circuit breakers when powering on through the Power Plants. This is because Power Plants have far more current capabilities than the wall outlet. Normally, when a big amp turns on, it takes a huge rush of current to fill empty capacitors. Plugged straight into the wall AC socket, the relatively high impedance of the house wiring acts like a resistor - and momentarily allows a voltage drop at the plug. This added resistance shields the circuit breaker and it doesn’t trip. Do the same thing through a Power Plant and because there’s no drop in output voltage, it demands much more from the circuit to achieve that - and the circuit breaker can trip.
We solved that by adding our own “resistor” on a temporary basis until the amp’s power supply capacitors are topped off. Thus, the inrush limiter.
Subs are a whole other subject. I am not a big fan of plugging them into the P3’s filtered outlets. Other than protecting them from potential surges and spikes (after a power outage) I don’t think it helps to run them all off a single plug. If you have a regenerated output, that’s different.
So, my advice on the P3 is to run everything but the subs through it. If you have a P10, run everything through it.
Thanks, Paul - very helpful and informative response. Now it makes sense to me.
Manuals, I will read through when I get a device to make sure I don’t do anything stupid or need help with basic operation, but often much of it is meaningless unless or until you have a specific question from experience over time. Real-world explanations like the above for why something is designed the way it is are something I always value in a manual.
How would I know if I have “gear that could potentially draw more than the 800VA of regenerated AC the P3 is capable of outputting”?
VA is RMS Voltage x RMS current. As it is RMS, it includes peaks greater than than 800 Watts.
800VA is thus not quite the same as 800 Watts, but more than close enough for our purpose. Given that most subs use Class D amps and are rarely drawing much power, it is unlikely the sub needs to be plugged into a P3’s high current outlet as it will draw much less than 800 Watts peak; that is, less than 800VA. Save these outlets for large amps. Thus, I think you should plug the subs into the P3, regular outlets, to take advantage of the P3.
Are there instances such as crescendos that might be briefly drawing enough between a 2 or 300 watt amp and two 12″ subs that it would affect dynamics or sound in some way?
I seriously doubt it and if it ever does it would be rare. But vaguely possible depending on the amp, subs, speaker efficiency. If concerned it would be easy to find music to use as a test and to switch outlets used to power the equipment. I would not bother as I would rather listen to music than tweak/worry.
Don’t recall reading about it [inrush current] in the manual, but I read them about as much as most people – as needed.
As an insatiably curious sort, I read every manual I ever receive - cover to cover; I have reading disease. Inrush current is not mentioned in the P3 manual as the P3 does not have current limited outputs. It is in the P5 and P10 manuals as these units do have such outlets.
Paul McGowan said
Subs are a whole other subject. I am not a big fan of plugging them into the P3's filtered outlets. Other than protecting them from potential surges and spikes (after a power outage) I don't think it helps to run them all off a single plug. If you have a regenerated output, that's different.
Paul, can you expand on "I don't think it helps to run them all off a single plug?" Why? Are you suggesting it is better to put the subs on a different house circuit?
Elk - thanks, though it’s mostly Greek to me. The only other times in my life I ran into VA was from electrical suppliers at conventions, and out on the neighborhood telephone pole.
Confused again though, as the quote about the “800VA of regenerated AC” is from the P3 manual regarding the HC outputs. Is that not the same as “current limited outputs”?
When I power up my amp, it trips the breaker above left of the transformer. Pisses Com Ed off. Guess I’ll have to scale down from the 100kVA amp I’m using. Besides, it’s too hot in the summer, though I don’t need to heat the house in the winter ; )
badbeef said
Confused again though, as the quote about the "800VA of regenerated AC" is from the P3 manual regarding the HC outputs. Is that not the same as "current limited outputs"?
The phrase "current limited" was a bad choice of terminology on my part when referring to the inrush circuitry of the P5/P10.
The P3 manual explains:
“. . . the HC zone does not output regenerated AC, and instead provides filtered and protected AC from the mains. This zone is intended for gear that could potentially draw more than the 800VA of regenerated AC the P3 is capable of outputting.”
The high current zone on the P3 is not current limited. It provides whatever the wall outlet can supply, but it is filtered. It is for equipment which draws more than 800VA. On the other hand, the regenerated power outlets of the P3 can only produce up to 800VA. In this way they are “current limited” as they can supply only this amount of current, but this is different from the inrush current limiting circuit in the P5/P10.
The high current outlet on the P5/P10 is briefly current limited upon initial turn on. It employs an inrush limiter to slow the current supplied to the equipment plugged into it, keeping the capacitors and transformers from drawing too much current on start up. Paul did a great job explaining this. This is what I was referring to as “current limited.” Sorry for the confusion.
Paul, can you expand on “I don’t think it helps to run them all off a single plug?” Why? Are you suggesting it is better to put the subs on a different house circuit?
Even if they are on the same circuit I prefer multiple cables as close to the source as possible (the “source” defined as the AC receptacle in the wall). It’s a small and niggling point. Anal and obsessive to be sure. The only difference being that instead of multiple arms coming off one external power cable (the one feeding the P3), you have the arms of the star feeding directly into the AC wall socket instead.
My preference is always a star wiring system where each piece of kit is connected via its power cable to the “source”.
The exception to this is a regenerator. A regenerator is better (even though it too is fed from a single power cable) because it has the advantage of an active circuit to lower impedance and regulate voltage and current delivery—a luxury not afforded a passive conditioner.
Speaking of starring into the source - that 75KVA transformer was an interesting education (for me anyways - you Double E guys will likely roll your eyes).
We had flaky power on my block for years, but the brown/blackouts were few and far enough between that I never felt compelled to buy a gene until a night spent with my family bailing the basement out in a thunder and lightning storm. Dumb as hell in retrospect, standing in ankle-deep water in the backyard, dumping garbage cans full of water so it would go downhill…with lightning flashing all around.
Anyhow - the transformer blew, which was 50KVA servicing maybe a dozen or so houses, all of whom were at various points updating their service from 100 to 200 amps.
ComEd came and replaced the transformer, and the Very Next Morning, there was a hellish storm, and I was looking out my back door at it, when a bolt struck VERY close (no lag between the light and sound, body-thudding bottom, etc.), and the brand-new transformer fried.
The next morning, the utility guys were driving around restoring power and replacing what they could. They couldn’t believe the transformer had been replaced the day before. All they had left on the truck was a 75KVA transformer, which they considered seriously over what was called for. I said, “Hook us up!”. He showed me the melted “fuse/breaker” that is inside the insulator in the picture - it’s basically a lightweight aluminum rod like a 40-penny nail. The lightning beat it. The wire on top, which is bare metal, is the 75,000 volt live supply feeding the transformer where it is broken into three legs, and then feeds the homes.
ANYHOW, after this, the power got more STABLE and QUIET. So if you find yourself in a similar position, go for the upgrade!
The wire on top, which is bare metal, is the 75,000 volt live supply feeding the transformer where it is broken into three legs, and then feeds the homes.
Just an FYI, most likely the primary voltage in your part of Chicagoland is 12,470V, less likely 4,160V (it's for sure not 75,000V). Some of the older, not updated, parts of the city and suburbs like Evanston have some 4160V. Most remaining 4160 is being upgraded to 12,470.
The long white rods are cartridge fuses. Work the same as the fuses in our amps, just at higher voltage.
P.S. That’s phase-to-phase voltage of a three phase 4 wire primary voltage system.
Amsco15 - I could’ve sworn that’s what the ComEd guy told me after showing me the fuse and popping a new one in and closing it gingerly with his 20’ pole. “That’s the 70,000 volt line”. I suppose just because he can change a fuse doesn’t mean he knows the system. ; )
Glad the HC matter has been clarified for the P5 (and P10). In setting up the P5 a few months ago, I was disappointed and not understanding why the first HC inlet was set up so close to the main power inlet that a common-sized audiophile cord connector wouldn’t fit. Well, even with the explanation, it still doesn’t, but at least I’m not missing anything power (current) wise.
I have not had any issue with having insufficient room between the power input and outlets.
In any event, I do not understand how the HC outlet works would have an impact on spacing. What were you expecting to learn? perhaps I missed something.
