Amp Shutting Down, need help

Just curious is the multi meter voltage section reading true RMS?

Yes it reads true RMS.

Its easy enough to test for. There is someone on this forum who makes AC extension outlets that have the DC Blocker built in. Just use one of those and you would know if that's what it is.
08-22-12: Atmasphere

Atmasphere,

Agree....

The Agon's members username is Gbart.

Email address, sae2300@optimum.net



>>>>

Jim, wouldn’t his other “standard 15 amp” outlets, throughout the apartment, be split up between the two incoming legs? He has tried, unsuccessfully, to energize the amp from various 15 amp locations around the apartment, though it isn’t known how they are split up.
Frank
08-22-12: Metro04

Frank,

Maybe.... But not necessarily. Back in the 1970s it was not uncommon to put most of the 15 amp convenience outlets in the living room and bedrooms on the same 15 amp branch circuit. Sailcappy had a 50/50 chance the circuit/s is/are fed from the other Line.

Sailcappy could check if the receptacle/s he plugged the amp into is fed from the same Line, leg, as the dedicated circuit.
Each breaker space down each side of the panel alternates from one Line to the other.

Example Line 1, L1, is the top breaker as well as the top breaker across from it.

2nd breaker down is fed from L2 as well as the one across from it.

And so on down each side of the panel.

Glad you brought up again that Sailcappy tried other outlets in his apartment.... Those in the living room as well as bedrooms are more than likely 15 amp branch circuits fed from a 15 amp breaker....

Sailcappy, is that correct? A 15 amp breaker? IF 15 amp, during the test, did the 15 amp branch circuit breaker ever trip?

I should mention, the breakers in the panel are thermal/magnetic type breakers.
.

Sailcappy, is that correct? A 15 amp breaker? IF 15 amp, during the test, did the 15 amp branch circuit breaker ever trip?

Not counting the two breakers for the environmental conditioners; there are two 20 amp breakers, and three 15 amp breakers. I have tried the unit on all 5 of these circuits and the Cary still tripped after 20 seconds. The breakers in the main circuit breaker box never tripped.

Sailcappy,

So during the tests on the 15 amp circuits not one of 15 amp breakers tripped. But the 15 amp magnetic breaker on the Cary amp did......

And of all the 5 circuits the amp was tested on the odds are great that at least 2 were on the other Line in the electrical panel than the dedicated 20 amp audio branch circuit.


I spent a little time researching the Synergistic Research Powercell 10se MKII power conditioner.

I never did find any detailed specification on the thing.
Must be top secrete or something.

Do you know if the thing has any built in surge protection?

Does it have an isolation transformer inside?
.

Well, one thing that seems to be clearly established at this point is that the problem is related to inrush current occurring at the 20 second point, whether its root cause is DC offset + failure of the DC block in the amp, per Ralph's suggestion (which strikes me as a clever and plausible theory), or some other kind of power anomaly, or oversensitivity of the amp's circuit breaker (even though it has been replaced once), or whatever.

And re the SR Powercell, although there is little in the way of technical detail that is available, one thing seems clear. Its design is based on different principles than most or all other conditioners.

Jim & Ralph, do you think it might be a reasonable gamble for Sailcappy invest either $215 or $239 for one of the BrickWall surge protectors, which also provide some degree of line filtering, and include a "series surge reactor current limiter; cascaded, auto-tracking dual polarity voltage limiters; dual pulse inverters," etc., with the onset of voltage clamping specified to occur 2 volts above the waveform peak. Specs here for the 2-outlet version, and here for the 8-outlet version.

I and a number of other A'goners use one, btw, with no reports of audible side-effects that I am aware of.

Regards,
-- Al

Hm. You could certainly try it. Anything that might drop the voltage a little would probably sort it out. We have ascertained that the issue relates to overpowering the breaker due to something to do with the incoming AC power.

It happens on any outlet in the area; its not related to which side of the line or whether there is leakage from another component. Its entirely to do with the power transformer and the incoming power.

I doubt that its a surge thing- it happens consistently. A surge would only show up occasionally. So I'm going with 'no, that won't help' in this case. Measured line voltage is fine so its not an over-voltage condition of any kind.

This is all assuming that the measurements are correct and the behaviors accurately reported!

Another possibility is a shorted current inrush limiter. A third possibility is that the breaker has developed some residual magnetism and no longer breaks at the right point- IOW its become too sensitive. Simple replacement of the breaker would solve that. Any one of these problems could be such that it would not show up elsewhere due to variables like line voltage and such.

For example if Cary put the unit on a variac when they tested it, the variac may well have functioned to limit the surge current enough so it was no worries. At the other field location, there could have been something with the wiring or the unit was plugged into a power strip with other gear already on it. Power strips only have one power cord, so there could have been a temporary voltage drop, eliminating the problem.

I like to go for the simplest answer as the best one so my thinking right now is the breaker itself is defective.

I like to go for the simplest answer as the best one so my thinking right now is the breaker itself is defective.
08-23-12: Atmasphere

Ralph,

I agree....

I would think both toroidal transformers would have to be the first items powered up on the amp along with the DC power supplies long before that last click is heard.....
I mean the active sequence start up circuity needs DC power to go through its functions. I have no idea what that last click, relay is doing....

I also believe the soft start circuitry of the amp is doing a good job smoothing out the current as the two toroids and DC caps of the power supplies are charging. In fact, because of the 20 sec time frame for start up, both toroids may not even be powering up at the same time.

I was surprised by the voltage load test readings Sailcappy measured at the end of the 50' 16/3 cord with the amp connected.

No load 118V and through the whole active start up sequence the voltage only dropped 3 volts!
Granted the impedance of the 50' cord would limit inrush current..... I still would have thought the VD would have been more than 3 volts.

I mean we are talking about a 7 channel power amp rated at 250 watts @8 ohms each channel.

I think I would call Cary and ask them what it would cost to change out the switch breaker to just a switch and add an accessible fuse holder and fuse on the rear panel and replace the cheap magnetic breaker.

I believe I counted 6 fuses in the amp already.... What's one more.....

A look inside the Cary 7.250 Amplifier.

08-23-12: Jea48 “I would think both toroidal transformers would have to be the first items powered up on the amp along with the DC power supplies long before that last click is heard.....
I mean the active sequence start up circuitry needs DC power to go through its functions. I have no idea what that last click, relay is doing....“

I would speculate that the standby circuit is merely a passive or solid state design (no transformer) to minimize idle/standby current - fed after the magnetic breaker, which then feeds the delayed progressive interlock power-up circuits, which then controls the toroid’s power relays where any “soft start” circuitry might be interfaced, or something along those lines.

“I was surprised by the voltage load test readings Sailcappy measured at the end of the 50' 16/3 cord with the amp connected. No load 118V and through the whole active start up sequence the voltage only dropped 3 volts! Granted the impedance of the 50' cord would limit inrush current..... I still would have thought the VD would have been more than 3 volts. I mean we are talking about a 7 channel power amp rated at 250 watts @8 ohms each channel.”

I would have expected a larger dip as well unless it *was* slightly larger, but the refresh-rate of the meter was too slow in conjunction with a very short soft-start period (milliseconds). Granted, all outputs were unloaded, but the size those two toroid’s KVA rating would commend a substantial inrush without a soft-start. Orrrrrr, I'm betting because the mag-breaker tripped before the meter read the actual larger voltage drop.

Which now gets to Ralph’s speculation regarding the mag-breaker’s condition. If we knew what the typical (unloaded) inrush current was after the 20 second delay, within an ideal supplied AC scenario, we would have a better idea how close we’re getting to a *healthy* breaker’s 15 amp trip threshold vs. sailcappy’s suspect breaker.

Frank

Orrrrrr, I'm betting because the mag-breaker tripped before the meter read the actual larger voltage drop.
08-23-12: Metro04

Hi Frank,

The magnetic breaker doesn't trip when the 50' 16/3 cord is used.

Which now gets to Ralph’s speculation regarding the mag-breaker’s condition. If we knew what the typical (unloaded) inrush current was after the 20 second delay, within an ideal supplied AC scenario, we would have a better idea how close we’re getting to a *healthy* breaker’s 15 amp trip threshold vs. sailcappy’s suspect breaker.
08-23-12: Metro04

Agree.....

I asked Sailcappy in an earlier post, I believe, if his friend had a clamp on amprobe to check the current draw of the amp through its start up cycle.... The meter would need to be a true RMS.

His friend would need do a little surgery on an old short power cord carefully cutting away the outer jacket exposing the 3 insulated conductors inside about 6" to 8" or so.

For the test.

The Cary amp plugs into the short power cord.
Clamp the Amprobe around the exposed insulated hot conductor.
Set the Amprobe so it will lock onto the highest reading.
Plug the short power cord into the wall outlet.
Fire up the cary amp.
The Amprobe will lock onto the highest ampere reading just at the point the magnetic breaker trips.
.

"Hi Frank, The magnetic breaker doesn't trip when the 50' 16/3 cord is used."

Uhhhh, yeeeaaah.... I was just seeing if you were paying attention. LOL!

Seems I get these A.D.D. attacks more frequently ever since upping my Cialis treatment from a PEZ dispenser, to one of those cranial-sported gravity drip-feeder apparatuses. The T.V. adds make it look so harmless.

The fact that a co-worker walked in on me wearing a L'il Bo Peep outfit, while typing, may have affected my train of thought as well. No excuses... Just sayin'

Frank

Uhhhh, yeeeaaah.... I was just seeing if you were paying attention. LOL!
08-23-12: Metro04

LOL....
.
Jim

Not quite sure what the suggestions are at this point. I have decided to purchase a DC Blocker from Gbart on Audiogon. He has graciously offered to build me one. It should be ready next week. I will up date you after it are installed.

Is the Brick Wall Surge protector something that should be installed prior to the SR Power cell or just after the SR Power Cell and the Cary? Right now I have two plugs on my outlet one goes to the SR Powercell (which has my OPPO, Theta Pre-Pro, 2 Red Dragons, Runco and Sonos) and the other goes to the JL Sub.

Thanks again.

Is the Brick Wall Surge protector something that should be installed prior to the SR Power cell or just after the SR Power Cell and the Cary? Right now I have two plugs on my outlet one goes to the SR Powercell (which has my OPPO, Theta Pre-Pro, 2 Red Dragons, Runco and Sonos) and the other goes to the JL Sub.

I had been envisioning that the Brick Wall would replace the Power Cell altogether, if it in fact solves the problem. It would plug into the wall outlet, and (assuming that you purchase the 8 outlet version) everything else would plug into it (aside from the JL sub, if its current requirements and those of everything else total up to exceed or to be uncomfortably close to the Brick Wall's 15A rating).

There would be no harm, though, in experimenting with other configurations that utilize both the Brick Wall and the Power Cell, with the amplifier powered via the Brick Wall and some or all of the other components powered via the Power Cell.

Regards,
-- Al

Cappy, I was under the impression that Brick Wall was merely *another* recommendation for your Cary's situation, just like the DC blocker, and to be used solely with the Cary *if* either device resolved its power-up problem. I would continue to use the SR for everything else, excluding the sub.

Where will the Cary be located vs. all of your other upstream equipment? Was *everything* intended to run off the new 20 amp circuit (amp, sub, pre/proc, etc)? Just trying to envision your layout.

I'm surprised you're not waiting for your friend Ken to test the AC with an O-scope rather than gamble on money spent that may not address the Cary's issue. To Ralph's point about slowing down the inrush current, regarding a sensitive mag-breaker, I would have thought the SR would've provided some amount by design, including some level of DC blocking, though unsure about the DC.

See what the DC blocker does first, when feeding the Cary directly, since you bought it already.

Frank

Currently I have a dual outlet connected to a 20amp circuit. That circuit is shared by one other outlet in my apartment. I plug the SR Powercell into one of the slots and my JL sub into the other one. All my other equipment is plugged into the SR Powercell.

My plan is to first keep the same power path for everything and put the DC blocker between the SR Powercell and the Cary Amp. I might also try to put it between the SR Powercell and the wall outlet. Stray DC should be bad for all my other components, right?

If all this fails I will then sell this DC blocker to anyone who wants it on AG. I will then try the Brick Wall and play with the same signal paths as the DC Blocker.

Does this sound like a plan?

Ken is gone on vacation for a few weeks so I will try these solutions as they are not a real budget buster. If they don't work I can always sell them.

Finally if none of these suggestions work I will try to work with someone who can help me re-configure the current 15 amp circuit breaker with something that is less sensitive to inrush current. It will probably void my Cary warrantee but I can’t have this extension cord in my living room anymore.

Sounds like a plan to me, except that my instinct would be to avoid configurations in which the Brick Wall and the Power Cell are used in series. If you are using both, have them both plugged directly into the wall.

Also, given the small difference in price between the two versions of the Brick Wall, I think it would make sense to get the 8-outlet version. That would give you the flexibility to experiment with what gets powered from where.

Regards,
-- Al

Sailcappy, I am really sold on the idea that the breaker is at fault. Have you been using it as a power switch? Or is the amplifier designed with it being the power switch?

Either way what I would do is replace the breaker... troubleshooting from a distance is always tricky, but we can be very sure that the solution has to do with the inrush current on the power transformers.

08-24-12: Atmasphere
"Sailcappy, I am really sold on the idea that the breaker is at fault. Have you been using it as a power switch? Or is the amplifier designed with it being the power switch?"

Based on the mag-breaker's rear location, the amp's remote-trigger feature, and front-actuated Power/Standby pushbutton switch, it's intended as an "actuate-and-leave it" protection device. Although, with all his troubleshooting prior to and well after Cary's diagnostic testing, that particular mag-breaker has probably been subjected to several dozens of set/trip cycles. Certain internal electro-mechanical aspects could be deteriorating, though lacking the component's specs/data information, and additional dianostic measurements, it's an educated assertion - something most experienced techs would investigate in any applicable field of electronics.

If the two filter options fail to resolve your issue, I wonder if Cary would sell you a replacement breaker. Is your skillset up to changing that component (which *should* be a breeze), or maybe your friend could do it rather than sending the amp back? Even if Cary won't sell you one, the component's mfr info/PN is probably still available on the breaker's body once it's accessed within the amp (possibly by removing the bottom panel) - thus likely availability unless a custom-spec'd option.

Frank

When the problem first occurred Cary sent me a new circuit breaker which is the ON/OFF power switch. I installed it which was easy to do. The problem is not with the breaker being defective. Remember it works fine at Ken's place of work.

My updated plan is to:
1. Try the DC Blocker if that does not work....
2. Try the Brick Wall if that works I will replace the SR Powercell with the Brick Wall.
3. If the Brick Wall does not work then I am at a loss.

08-15-12: Sailcappy
I have had it replaced to no avail.

I *thought* I'd read someone mentioning the breaker was replaced, but couldn't confirm yesterday when quickly going back through the posts, so I wasn't 100% sure and am entertaining Ralph's (Atmasphere) concern considering the breaker's accumulative set/trip cycles, *if* it was still the original. Also, based on first-hand experiences, have had to replace numerous "new" components after immediate or delayed faulty operation, especially regarding a device unintended for elevated repetitive mechanical cycling.

Regarding the amp working at other locations (which I've always taken into consideration), Ralph posted some scenario possibilities that may allow a deteriorating breaker to continue functioning, and I agree is possible. Lacking any witness confirmation, or actually being there to assure apple-to-apple testing/comparisons, all we can do is speculate. He is quite knowledgeable, as with Al and Jim. We all come from decades of professional backgrounds in various electronics fields and offer legitimate suggestions based on scenarios and probabilities we've encountered over the years. All of us would *prefer* to be there - armed with appropriate test equipment - able to make better determinations. That's what I do for a living. So, lacking factual data, all one can do is suggest trying different things with hopes of resolvement.

Your updated plan is fine if unwilling to wait for Ken to return and 'scope your AC (the best *practical* option to minimize guessing). If the two devices fail to resolve, either keep or sell them, and take my joking recommendation to neatly coil-stack an appropriately rated ext cord and hide it out of sight behind other equipment, rack/furniture, etc., or package it cosmetically. You're planning to power the Cary from the conditioner, so, will *all* of the electronics be accumulated in one location near the 20 amp outlet? ...On a vertical rack, shelves, table-top, etc. - thus able to hide a majority of a coiled flat or stacked (black) ext cord?

If the Brick Wall works, it's not very WAF either, so how would you address that vs. a "shaped" ext cord, if the BW doesn't work. I can't envision a scenario where the cord couldn't be hidden or repackaged cosmetically, even if the amp is remoted across the room. It still requires a cord that has to plugged *somewhere*, and you plan to feed it from the SR conditioner. Describe your equipment layout if otherwise.

Again, if we *knew* exactly what was wrong (if anything) with your AC, if not equipment related, could better diagnose and recommend specific cures.

Hi frank,

......

If the two devices fail to resolve, either keep or sell them, and take my joking recommendation to neatly coil-stack an appropriately rated ext cord and hide it out of sight behind other equipment, rack/furniture, etc., or package it cosmetically.

Key words here are "appropriately rated ext cord". For the Cary 7.250 amp to perform sonically as it was designed to sound, imo, the minimum wire gauge would be #12awg.

50', times two, of 16ga is staving the amp of needed dynamic power.

A 50' 12/3 cord coil would be fairly bulky in size.

And more importantly with a 12/3 cord, I believe, the magnetic breaker would not hold on active start up and trip open.

>>>>>>>>>>>>>>>>>>>>>>>>>

Sailcappy,

I asked in an earlier post if you have any info on the SR Powercell.
Does the unit have a built in isolation transformer?
If so an isolation transformer will not pass DC offset from the primary winding to the secondary winding....

The SR Powercell could correct a poor power factor problem if it is so designed......

It will not block harmonics, that it unless it has a Mitigating harmonics cancelling type transformer..... And I doubt that it does. The cost of the SR Powercell would have been more than $5K. And I doubt if the unit has any harmonics filters built in.... I would think the specs would say so if it did though.

I also asked you if the SR Powercell has built in surge protection, SPD, for connected loads.

The info would be helpful in solving the Cary amp's problem.

Sailcappy, you mentioned in an earlier post if the Mains power feeding your apartment is the problem the landlord would not help, pay, to clean up the power. Probably true..... But there are things that you can do on your end.

Some remedies would require the permission of the landlord.
The landlord also may require his authorized electrical contractor install any harmonics filters or what ever is needed to solve the problem. No doubt you will bear the cost.

You first would need to hire a Power Quality testing company to verify and find the problem/s.

The problem with the Cary magnetic breaker tripping could be a Canary in a coal mine...... IF,.... the mains power feeding your apartment is of poor quality, from harmonics, the life of your audio equipment could be shortened......

http://www.hammondpowersolutions.com/upload_files/hpsi-ta5.pdf

http://www.fluke.com/fluke/twen/solutions/pq/troubleshooting-power-harmonics.htm

http://www.psihq.com/iread/harmonic.htm

http://www.artechepq.com/assets/files/SinglePhase.pdf

[url]http://www.cpccorp.com/harmonic.htm[/url]
.

Again I can not thank all of you enough for your trouble shooting ideas. No updates to report as of now.

As far as the SR PowerCell is concerned
1. It is not a Surge Protector
2. It does not have a Transformer
3. It does not treat for harmonic distortions.
4. All I can get out of SR is that the unit uses a EM Cell to filter AC.

DC eliminator should be ready by Friday.

I had GBART make me a DC Blocker and plugged it in and it did not solve my problem. I will say that GBART created a beautiful box for me. Really good quality. I highly reccomend him if you have DC Blocking needs. BTW mine is now for sale as I do not have DC issues with my line. Check it out under DYI.

On to the Brick Wall. More info to come.

Sailcappy, what happens if you short the input of the amp? Does it still do it?

Do you mean use a cheater plug? I tried that and it does not work.

No. I mean the signal input of the amp.

Not quite sure what you mean. How do i do that?

Sailcappy, Ralph is referring to seeing if the problem occurs when the input connectors of the amp have shorting plugs, such as these, on them.

If you don't have any, you could pick up some RCA plugs at Radio Shack and solder their center pin and the ground sleeve connections together.

Alternatively, you could connect RCA cables to the amp, leaving their other ends unconnected, and WHILE THE AMP IS TURNED OFF stuff some aluminum foil into the unconnected ends of the cables to short the RCA center pin and ground sleeve together. You would want to make sure that the foil is securely in place, so that it won't dislodge when you turn the amp on, and to be careful to not let anything or anyone touch the RCA plugs while the amp is on (and for a minute or more after it is turned off).

I'm not sure what possibility Ralph is envisioning in suggesting that experiment, though. Perhaps that the current surge that occurs at the 20 second point is causing a transient to couple to the inputs of the amp, and to then be amplified to excessive levels, somehow resulting in the breaker tripping.

Regards,
-- Al

Should I put shorting RCA's on all seven of the inputs? What do i do with the XLR's?

Sailcappy

Installed the Brick Wall today and it did not solve the problem.

I guess Ken and his Oscilloscope is the only solution.

I guess Ken and his Oscilloscope is the only solution.
09-03-12: Sailcappy

Not the solution but maybe find the problem.

Sailcappy,

While you are waiting for ken....

It was suggested to me, by an AA member, to try the amp in another apartment in your high rise building.

He also suggested you check the common house corridor on your floor, outside your apartment, for a receptacle you could plug the amp into. There is a very good likelihood the receptacle, in the corridor, is fed from a different distribution power transformer than your apartment electrical panel.

If it were me, by now I would be either trying to get my money back or llooking to sell the amp. Before owning my own house, I lived in an apartment with a single 15A circuit serving the entire place. It does not get worse case than that. I owned several high powered amps during that period and never once experienced a shutdown problem. Cary gave the amp a clean bill of health, therefore it should not be having the issue. The amp seems like more trouble than it's worth, IMHO.

I agree. They will not give me my money back. They are willing to send me a new one. Do you think it is worth a try?

I agree. They will not give me my money back. They are willing to send me a new one. Do you think it is worth a try?
09-04-12: Sailcappy

Through the dealer you bought the amp from?

If so, yes..... But have the dealer sell the new amp on consignment.

From everything you have told us in this tread,

*You sent the amp back to Cary. They said nothing was wrong with the amp. Checked out fine.....

*You had them send you a new 15 amp magnetic breaker. That breaker trips.

*The amp works fine at your friends house.

I can't believe you have moved the amp around as much as you have..... The specs says it weighs 105 lbs....

What makes you think the new amp will work in your apartment?

The only way I would try the same amp in your apartment is if Cary replaces the 15 amp magnetic breaker with an on/off main power switch and adds a fuse for overcurrent and short circuit protection. Get rid of that magnetic breaker.....

It maybe time to cut your losses and move on.

Take the new factory fresh sealed box amp and have the dealer sell it to recoup most of your money.
To be honest the dealer shouldn't charge you a dime to sell the amp for all the problems you have gone through with the amp.

When the dealer sells the new amp he refunds you your original purchase price less the sales tax.

Beat the hell out of selling it as used all over again if the thing does not work in your apartment. And who wants to buy a used amp that is so finicky it may not work in the buyer's home? I wouldn't touch the thing with a 10' pole.....

Life is too short!

When i get the Oscilloscopes what should I be looking for? Is there a setting I should use?

I am betting that once we find the real problem with my ececticity a real solution could be found.

When i get the Oscilloscopes what should I be looking for? Is there a setting I should use?

I described one of the things that should be done in my post dated 8-18-12. Also, you should look for any major distortion of the 60 Hz waveform. Ideally it should look like a close approximation of a 60 Hz sine wave. If you see anything questionable try to photograph it, and post the photo at one of the free online photo-sharing services, with a link to it here.

As far as settings are concerned, there are a great many of them, so try to have Ken guide you through this. Also, of course, be cautious of the fact that you will be connecting to a potentially lethal voltage.

Sorry that the Brick Wall didn't help. Before selling it, it may be worth your while to compare sonic results between it and the SR, powering the entire system from one and then the other.

Regards,
-- Al

When i get the Oscilloscopes what should I be looking for? Is there a setting I should use?
09-06-12: Sailcappy

Sailcappy,

A lot depends on the power quality analyzer Ken is able to borrow from the company he works for. And more important how to use the instrument and interpret the info.

*Ken will need to check for odd Harmonics, voltage as well as current distortions.

*Poor PF, power factor, lagging as well as leading.

*Voltage sag.

He needs to measure the current draw of the Cary amp as it goes through its active start up cycle. Especially the current draw at the point the 15 amp magnetic breaker trips open. At the same time measuring the voltage.

If the current through the breaker exceeds the 15 amp rating then he will need to figure out the possible reasons why.

Harmonics?

Lagging or leading poor power factor?

Voltage sag? Depending on the power supply/s of the Amp
a voltage sag can result in an increase in current draw.
SMPS.....
So if the voltage sags, is the power supply drawing more current to compensate exceeding the 15 amp rating of the magnetic breaker?

As I have said in earlier posts your best bet is to hire a Power Quality expert. A person who is trained in the field of Power Quality.
.

For the hell of it I tried a grounding adapter (cheater plug) and grounded it to the Circuit Breaker box, kitchen metal water pipe and to my outside lighting rod grounding wire. Same problem so it is not a ground issue as we all agreed.

Just keep trying things until I can get someone to look at my electric.

All the lengthy power cord is doing is dropping the AC voltage a little over its length. But I had understood that you had checked the AC voltage and it was OK. If the voltage was high then I could see the power cord helping out. That is why I suggested other things. Any chance of getting another AC voltage measurement at the wall socket?

Hi Ralph,

I learned a couple of weeks ago from Jon Risch, an EE as you know, that a SMPS will draw more current if the voltage sags to try and maintain output power of the PS.

Sailcappy has verified the mains voltage at the dedicated branch circuit receptacle is 118V using a true RMS meter. That is only one volt above what the manufacture recommends for the amp.

In Sailcappy's test he ran for me, with out the 50' 16/3 cord connected to the amp, amp plugged directly into the wall recept, the mains voltage dropped from 118V to 112V at the same instance the 15 amp magnetic breaker tripped open.

With the amp connected to the 50' 16/3 cord the voltage at the end of the cord was 118V unloaded, naturally, and at the sound heard from the last relay closing the voltage dropped from 118V to 115V then back to 118V as the amp
completed its start up cycle.

So is the 50' cord working more like a current limiter
keeping the current below the 15 amp cutoff of the magnetic breaker trip solenoid mechanism?

It would be interesting if Sailcappy were to plug in a 120V table lamp with a 60 watt incandescent light bulb into one of the recepts of the branch circuit that feeds the Cary amp, then start the amp up, plugged directly into the wall recept. I wonder how dim the light gets at the split second before the magnetic breaker trips open?

A lot? Somewhat?
.
Jim

Sailcappy has verified the mains voltage at the dedicated branch circuit receptacle is 118V using a true RMS meter. That is only one volt above what the manufacture recommends for the amp.
09-10-12: Jea48

That is only one volt above what the manufacture recommends for the amp.

Should say,
That is only one volt above the minimum line voltage the manufacture recommends.
From the Cary 7.250 specs, (AC Power Requirements 117/234 Volts AC @ 50/60 Hz)

Also after rereading my last long winded post I am not sure I made clear what I was trying to get at.....

That a SMPS will draw more current if the line voltage sags to try and maintain output power of the PS.

So, Is it possible the voltage drop from 118V to 112V is enough to cause the SMPS to draw more current to compensate for the drop in line voltage?
End result the 15 amp magnetic breaker ampere rating is exceeded, breaker trips open.
.

Jim -- I don't see the 117V being indicated as a minimum. I would assume it is intended as a nominal value.

Best regards,
-- Al

Jim -- I don't see the 117V being indicated as a minimum. I would assume it is intended as a nominal value.
09-11-12: Almarg

Hi Al,

Ya, I agree. I knew better... I'll just have to blame the thought on a brain fart moment.

120V may be the nominal voltage in the US but it is not unusual to see line voltage vary anywhere from 110 to 124.
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Jim

Switch mode supply??! I figured this thing had a big toroid...

Clearly the current limiting of the cord is having an effect.

So what is the outlet voltage while the amp and the cord are doing their thing? Bet it does not drop as much.

Based on that I would replace the AC receptacle, and make sure the screws on the receptacle are tight!

It would be a really good idea to see how this amp behaves in another apartment in the same building...

I do not think the amp is at fault if it really is SMPS powered.

Switch mode supply??! I figured this thing had a big toroid...

Hi Ralph,

Yes it has two big toroids.

Am I wrong in my thinking the amp could still have switch mode power supplies?

LOL, it wouldn't be the first time I have been wrong.....
Jim

"09-11-12: Atmasphere
Switch mode supply??! I figured this thing had a big toroid..."

They appear be two large toroids. If not, they would be the largest SM "inductors" I've ever seen for fairly moderate current demands of this nature, and I believe their distance and wire lengths would be of issue in a SMPS as well. If we could see what’s under the amp’s internal/central panel, I’d expect to see a bank of large electrolytics for a linear PS.

"So what is the outlet voltage while the amp and the cord are doing their thing? Bet it does not drop as much."

I can't recall if a measurement was taken at the outlet WITH the 50 Ft ext cord incorporated, but without it, the voltage dropped from 118 to 112 at the same outlet right when the mag breaker tripped.

"Based on that I would replace the AC receptacle, and make sure the screws on the receptacle are tight!

Note: The amp trips exactly the same way via 4 or 5 other outlet locations within his apartment per sailcappy.

"It would be a really good idea to see how this amp behaves in another apartment in the same building..."

I concur, as Jim and his EE friend has suggested, though not yet not tested by sailcappy. I recall Jim even suggesting he try to locate a service outlet outside or between apartments (if a cooperative neighbor wasn’t available).

Frank

If it has large toroids, there is no SMPS. A SWPS might look like an aluminum box inside the unit, but certainly would not sport any toroids, especially large ones.

So the theories around SMPS are not.

I still think its a good idea to try this amp in another place in the same building. Also, it would be a good idea to get the AC voltage readings from the wall when the amp is plugged directly into the wall, and also what the outlet voltage is when the amp energizes at the other end of the power cord. I'm thinking this might have to do with current inrush caused by an excessive dip in the line voltage at turn on, due to saturation in the core of the transformer caused by the dip itself when the transformer energizes.

If that is the case, it may be that replacing the outlet could sort it out....

If it has large toroids, there is no SMPS. A SWPS might look like an aluminum box inside the unit, but certainly would not sport any toroids, especially large ones.
09-13-12: Atmasphere

Ralph,

Thanks for the response. My limited understanding of SMPS was that a power transformer was not used. Then I got into a discussion with Jon Risch which I apparently got confused thinking SMPS could also be used with power a transformer.

I obviously misunderstood what Jon was trying to tell me.
My bad.... Thanks for setting me straight.

http://www.audioasylum.com/audio/tweaks/messages/18/184672.html

http://www.audioasylum.com/audio/tweaks/messages/18/184672.html

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Jim

Correction.
Should read,

Then I got into a discussion with Jon Risch which I apparently got confused thinking SMPS could also be used with a power transformer.

Anybody ever wonder why the hell the user cannot edit a post after xxxx amount of posts have been posted?
.

I will try to plug the unit into another outlet in the building. Belive it or not in the hall the outlets are twisted types so I can not use them. I am also looking into purchasing the Purepower 2000 which is an AC regenerator to try to solve my problem. If that works I will sell my SR Powercell.

No word on the O scope from Ken as of yet. The saga continues.