Hi Al,
By chance did you read the Cary owner manual?
http://caryaudio.com/pdfs/manuals_2012/Model7.250_manual.pdf
CAUTION.
If the unit is in active mode and power is removed, it will remain activated when power is restored.
>>>
So it looks to me after a forced shutdown, breaker trips, when the unit is reset and powered up, by resetting the breaker switch, the unit comes up active mode... Does the restart sequence take 20 seconds? Don't know....
OR
Does the breaker trip before the amp is "made" active?
What say you?
.
Jim |
Jea48: As you know, "inrush" current is typically instantanious - with PS filter caps charged to 95+% within a few seconds, or so, for most high-power amps.
08-15-12: Metro04
Note he's stating the breaker consistantly trips "after 20 seconds",
08-15-12: Metro04
Metro04, Good point.... His recent noted voltage drop to 112, only at the moment of trip, is curious.
Agree..... For a thermo-magnetic breaker, you'd expect to see sustained high current voltage drop right up until tripping vs the virtually unaffected static 118 - as if the power supply wasn't even pulling current (?).
Are we 100% sure what the trip mechanism is? The fact that the 50' extension cord allows the amp to work without tripping the overcurrent protection is baffling to say the least. Like I said earlier it could be working as a current limiter... I am not so sure now, that is case... If Sailcappy lives in a high rise apartment building hard telling what the power quality of the AC power looks like. I wonder if Sailcappy has talked to the superintendent or head of maintenance about his problem? They may split the cost for a "Power Quality Company" to check out his mains power quality. Harmonics http://p3-inc.com/whitepapers/harmonics.pdf . |
"Is the breaker a GFCI (Ground Fault Circuit Interrupter) or an AFCI (Arc Fault Circuit Interrupter)? These type of breakers have a test trip push button on them."
There are no test trip buttons on any of the circuit breakers in the breaker panel.
08-15-12: Sailcappy
I asked because you said the black and white wires of the branch circuit went to the breaker. 4. The White and Black wires connected to the circuit breaker seem to be 10 guage.
When a GFCI or a AFCI breaker is used both the hot conductor and the neutral conductor, of the branch circuit, terminate on the breaker. The breakers have a white pigtail that extends to the neutral bar in the panel. http://caryaudio.com/pdfs/manuals_2012/Model7.250_manual.pdf How do i contact almarg?
08-15-12: Sailcappy
Well under the new Agon system you can not.... All you can do is hope Al reads this thread..... . |
Things known. From the Cary's owners manual. *Uses a soft start circuit. That limits inrush current. *Has built in DC offset filter protection. (That would be after the magnetic circuit breaker) *Uses a magnetic trip circuit breaker. (Would not be my chose) *Cary works fine elsewhere outside OP's apartment. *Will not work anywhere on any branch circuit in the OP's apartment without the 50' cord attached. *Cary will not work plugged into the Synergistic Research Powercell 10se MKII power conditioner. More questions. What is the conductor wire gauge of the 50' extension cord? Is the 50' cord in a coil? Roughly the diameter size? A 50' coil with AC current passing through it is an air core inductor..... Inductive reactance....??? I do live in a high rise and my building said and I quote "as long as the breaker is not tripping then we do not concider you to have a problem." So much for living in a "luxury building".
Sailcappy
Well with a magnetic trip circuit breaker Harmonics can cause them to nuisance trip. Sailcappy, you mentioned your friend works for a power company. Does he have access to test equipment to check the power quality of the power feeding your apartment? http://www.copperinfo.co.uk/power-quality/downloads/pqug/31-causes-and-effects.pdf Reading from the owners manual it talks about putting the amp in "standby" mode before turning it off with the switch/circuit breaker. Not doing so leaves the amp in "Active mode" state. I assume you are powering the amp down correctly. I ask because of the test you performed where just as the breaker tripped you notice the voltage dipped from 118V to 112V. The VD, voltage drop, was due to a spike in current. Was it the protection relay switching in the Cary amp? Can't say 100% the VD was due to the Cary or maybe due to a high current load turning on elsewhere in your apartment. Though what are the odds it happened at the same time the breaker tripped. . |
Hi Al,
I hoped you would see my post.
As Metro04 pointed out more than likely the electrical equipment grounding conductor for the branch circuits is the metallic conduit, boxes, and fittings. Back in the 1970s that was acceptable per NEC and more than likely NYC codes. (Problem, years later, was the degradation of electrical continuity integrity from the fittings, connectors, lock nuts, and conduit couplings.
Corrosion for one, = resistance. If we have resistance then a difference of potential can exist from the grounded neutral conductor and the safety equipment grounding conductor at the branch circuit outlet device, the receptacle.
To rule any chance of noise on the safety equipment ground I would think, for test purposes, a ground cheater could be installed on the power cord of the Cary Amp.
What are your thoughts on the magnetic field of the 3rd and 5th harmonic on the relay solenoid of a magnetic breaker? I would think it would distort the actual current passing through the switch/magnetic breaker on the back of the Cary amp.
Harmonics is about the only thing I can think of that causes the Amp's magnetic breaker to trip in the OP's apartment but no where else outside of his apartment.
The fact that the 50' extension cord stops the nuisance tripping is interesting.....
I assumed the cord is coiled up and not laying out in the room. Appearance as well as being a trip hazard.
So, to me, at least two things are at play.
Size of the conductors of the cord.... Impedance....
Cord is coiled up...... inductance.....
Does that filter out harmonics or at least lessen the effect on the magnetic field of the solenoid of the magnetic trip of the breaker?
I asked the OP in a previous post if he was shutting down the Cary Amp by first pushing the power button on the front panel of the Cary putting the Amp in standby before turning off the power switch/breaker on the back of the amp. (Not doing so leaves the amp in the "Active Mode" state.)
The owners manual recommends not shutting off the amp without first putting the amp in standby.
With the problem the OP is having, unique only with his apartment, proper shutdown and power up could just be enough for the breaker to hold.
I would recommend the OP power up the amp with the 50' extension cord power off by putting the amp in "standby" first then turn off the switch/breaker.
Remove the 50' cord and plug the amp directly into the wall receptacle. Wait at least 5 minutes to power up the amp again. (Power supply caps should be bled off by then?)
I would then turn on the switch/breaker and see what happens. Hopefully the 20 second timeline will pass with no breaker trip event.
If the breaker does not trip, fingers crossed, I would not get in any big hurry to push the power button on the front of the amp that starts the sequence to power up the amp in the "Active Mode". Wait at least a few minutes or so.
If the amp does power up I would not power the amp totally down unless going on vacation or in the event of lightning storms. I would just push the power button on the front of the Cary putting the amp in standby.
Does it totally solve the OP's no.... And sad to say he would still need to keep the 50' extension cord. If he has a power outage the amp will be set to "Active Mode" and he will have to use the 50' cord to to reset the amp to standby.
Jim |
2. The 50’ extension cord has the following information imprinted on the jacket 16/3. I assume that means 16 gauge times three wires.
Correct... The cord impedance is limiting inrush current through the magnetic breaker of the Cary amp when the amp goes active.....
“I ask because of the test you performed where just as the breaker tripped you notice the voltage dipped from 118V to 112V. The VD, voltage drop, was due to a spike in current. Was it the protection relay switching in the Cary amp?”
jea48
4. Not sure what you are asking the 15amp breaker which is the on/off switch for the breaker trips it to the off position when I noticed this drop. Remember this happends after i go from standby mode to Active mode.
Sailcappy
The on/off switch/breaker is for FLA protection of the amp. Short circuit and or overload condition. The protection relay switches the amp from standby to active mode which I would assume sends power from the power supply to the power amps circuitry. The protection relay circuitry should also protect the speakers from damage in the event of amplifier malfunction. Test. With the 50' cord connected volume control set at minimum turn on the switch/breaker. With your ears close to the amp push the power button on the front of the amp. (Standby to active). More than likely you will hear a click/s.... That is the protection relay/s changing state. "I would recommend the OP power up the amp with the 50' extension cord power off by putting the amp in "standby" first then turn off the switch/breaker. Remove the 50' cord and plug the amp directly into the wall receptacle. Wait at least 5 minutes to power up the amp again. (Power supply caps should be bled off by then?) I would then turn on the switch/breaker and see what happens. Hopefully the 20 second timeline will pass with no breaker trip event. If the breaker does not trip, fingers crossed, I would not get in any big hurry to push the power button on the front of the amp that starts the sequence to power up the amp in the "Active Mode". Wait at least a few minutes or so."
jea48
9. The breaker only trips after I take the unit out of standby mode and put it into “Active Mode”. I am powering the amp in the following manner. I first turn the circuit breaker switch from the off position to the on position. I then press the button on the front of the unit which takes it out to standby mode into the Active Mode”. Without the extension cord the 15 amp ON OFF circuit breaker switch on the back of the unit trips to the off position. After it switched to the off position I put the unit back into standby mode (pressing the front button to standby) and start the process over again. Not sure if your reccomendation is valid.
Sailcappy
When the breaker trips all power on the load side of the breaker is disconnected from the Cary amp. Pushing the standby push button on the front panel will not do anything. As I read the owners manual the amp is still in active mode. From the owners manual. "Power Button. The Power Button performs no function when the amplifier is power off with the rear Master Power Switch. When the rear panel master switch is powered on the model 7.25 is in standby mode. Pressing the Power Button when the rear panel mater panel switch is powered on will activate the power amplifier"..... And so on.... NOTE. "When the status of the model 7.25 changes relay checks may be audible. This is normal operation." I suggest you reread the owners manual again. Section on, "Controls and Displays".
9. The breaker only trips after I take the unit out of standby mode and put it into “Active Mode”.
Sailcappy
Immediately after? The 50' 16/3 power cord is limiting inrush current flow through the magnetic breaker. . |
Hi Swampwalker,
I believe when the amp is first powered up using the switch breaker on the rear panel of the amp the breaker holds in the standby mode.....
The proper shut down procedure is to first push the power button on the front panel of the amp. That puts the amp in standby. The user can then turn off the amp with the main power switch/breaker on the rear panel of the amp or leave it on 24/7.
From what I have gathered from reading Sailcappy's posts, the amp could be left in standby indefinitely and not trip the magnetic breaker.
The problem starts when he pushes the power button on the front panel of the amp that starts the sequence from standby to active mode.
The switch/breaker is in series with hot of the 120V power.
That makes the breaker the gate keeper so to speak......
Jim |
Hi Al, 4. Not sure what you are asking the 15amp breaker which is the on/off switch for the breaker trips it to the off position when I noticed this drop. Remember this happens after i go from standby mode to Active mode.
08-21-12: Sailcappy
From what Sailcappy says in the quote above the breaker trips as the amp moves from standby to active. So question is what all is powered in standby? Just the power transformer? Or the transformer and DC power supply? Which relates to your point about inrush current. It is not clear to me when the major inrush current normally occurs. Does it occur:
Good question.... And then there is the soft start feature of the amp? Where is the circuit installed. Does it limit, smooth out the inrush on initial standby start up only? Or both standby start up as well as active mode activation? A related thought that occurs to me is that I would not assume that the voltage drop that was observed as the breaker was tripping was due to inrush current that normally occurs at that point. It seems conceivable to me that contact bounce occurring in the breaker as it tripped might have resulted in inrush current and voltage drop that would not occur at that time ordinarily. So the voltage drop might have just been a consequence of the breaker tripping, rather than reflecting a large inrush current that may have caused the breaker to trip. Or perhaps some sort of inductive kickback effect from the power transformer or a relay was responsible for the voltage drop, given especially that the amp was not designed with the expectation that it would normally be powered down from the active state by means of the breaker.
Agree... As I said in an earlier post it could have just been a coincidence at the same time some other load started and the VD occurred at the main electrical panel. How about that 50' 16/3 extension cord?? Yes the cord is too small for the amp.... But what about what is it doing? Two things come to mind. If the current does go up as the amp goes into the active mode then I would imagine the voltage drops. Available Power at the end of the 50' cord would be reduced. Enough so the amp is able to complete the process of going into active and playing music without tripping the magnetic breaker. You stated earlier you thought the amp might be reacting to voltage transients and thus causing the magnetic breaker to trip. Would a good SPD, surge protection device, installed between the amp and the wall outlet shunt out the high voltage transients? One last thought I wonder if it would help if the hot conductor of the 20 amp dedicated branch circuit was moved to the other line, leg, in the electrical panel? Jim |
Look! Every time I get close to addressing and finishing a few paragraphs in response, all you guys quickly sneak in answers and more questions! So, I'll just sit patiently in the corner with a "filthy bed-wetter" sign on and wait fer a bit. :-D
08-21-12: Metro04
LOL...... |
Sailcappy,
I forgot to ask. Is your friend, that works for the power company, an Electrical Engineer? An electrical technician?
The reason I ask is your friend qualified, confident, to preform work inside the electrical panel of your apartment?
Nothing major.... Just move the hot conductor of the audio 20 amp dedicated circuit to another 20 amp breaker on the other Line, leg, bus in the electrical panel. (Providing there are any spares. If there is not a spare he could use a breaker that is being used, for the test.)
If you are not sick of tests yet one more test you could try......
If the problem is poor power quality you could rule out the offending electrical device/s, equipment, appliances, CFL lights, ect, in your apartment is the cause.
You will need a flash light....
Turn off ever breaker at the electrical panel except the main breaker, if you have one, and the breaker that feeds the dedicated circuit to the Cary amp.
I lied, one more test. I would sure like to know what the VD, voltage drop, looks like at the end of the 50' 16/3 cord as the Cary amp is going through it's active start up cycle...... Especially that last relay click you hear.
If the 50' cord only has a single female receptacle you would need an additional receptacle to plug in the test leads of the multi meter. You could use a plug strip for the test? (Plug strip plugged into the 50' cord.)
. |
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?
. |
Uhhhh, yeeeaaah.... I was just seeing if you were paying attention. LOL!
08-23-12: Metro04 LOL.... . Jim |
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] . |
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.
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. . Jim |
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 |
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?
. |
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. Jim |
The 15amp circuit breaker (which is the on off switch for the amp) blows after 20seconds.
Now that is a horse of a different colour! Primary winding inrush current draw of the power transformer/charging electrolytic power supply caps is causing the circuit breaker on the amp to trip open...... The 50' cord is working like a soft start circuit limiting the inrush current draw to the Cary amp. At least that is what it sounds like to me. What can you tell me about the 120V 20 amp dedicated branch circuit. Distance from the electrical panel? Wire size? Electrical panel manufacture? Another test.... Multimeter set to AC volts. Insert the test probe leads into the unused receptacle of the duplex receptacle. Make note of the voltage reading. Cary plugged into the other recept. While watching the meter flip the switch on the Cary to the on position. Note the reading/s of the meter. Does the voltage sag several volts and remain low until the amp's breaker trips open? Voltage reading/s? OR Does the voltage sag and then swing higher than the original no load voltage? Voltage reading/s? . |
4. The White and Black wires connected to the circuit breaker seem to be 10 guage.
Is the breaker a GFCI (Ground Fault Circuit Interrupter) or an AFCI (Arc Fault Circuit Interrupter)? These type of breakers have a test trip push button on them. When I switched the Cary on the voltage did not change. Nor did it change during the 20 seconds it takes for the 15amp Cary breaker to trip.
Well that is good for the integrity of the branch circuit wiring. That tells me with the load connected the branch circuit maintained the supply voltage with little or no VD, (voltage drop) through the high inrush current cycle. That also tells me the branch circuit is capable of delivering the inrush current draw of the primary winding of the power transformer. However when the breaker did trip for a split second the votage meter read 112 volts.
I have a feeling the VD drop happened before the trip..... Question is what is it and why? At this point it would be good to hear from Almarg or Ralpf of Atma-Sphere Music Systems. As for your friends theory he could be onto something. By chance does your friend have a clamp on amprobe so you could measure the inrush current draw of the amp on startup? As for the circuit breaker used on the Cary.... Is the switch actually a breaker? The handle trips position and has to be reset? If it is indeed a breaker the more times it is tripped the weaker it becomes. Just can't beat a fuse for overcurrent protection for audio equipment..... Jim |
Sailcappy, Thanks for the detailed start up procedure. 1. Prior to doing anything I check that the rear breaker On/Off switch is set to the off position and the front Standby/Active switch is set to the Standby position.
......"and the front Standby/Active switch is set to the Standby position." Are you saying the front power switch is a maintained contact switch and not a momentary contact switch? In other words the push button switch has two positions, in and out? You did not give the shut down procedure but I assume you put the amp in standby by pushing the power switch on the front panel first and then flip off the switch on the back panel. 6. Music does not play during the first 20 seconds. When I use the extension cord after 20 seconds I get a final click that then allows music to play. It also turns on the LED light for the Cary Logo.
So the final click is the killer..... Have you thought about sending the Agon Link of this thread of yours to Cary service support? A look inside of the Cary 7.25. . |
Sailcappy, No I would not use the lightning bare 4/0 ground wire for an auxiliary equipment ground..... That could open up a whole new can of warms. • I attached a three way strip I had lying around into the end of the extension cord. I then plugged the Cary into one of the sockets and the voltage meter into the other.
• When turn the circuit breaker from Off to On the voltage at the end of the extension cord does not change. It remains at 118 volts. When I press the front button from Standby to Active the voltage remains at 118 volts for the 20 second duration. At that last relay click (at about 20 seconds) the voltage dropped from 118 volts down to 115 volts for split second and then back up to 118 volts.
08-22-12: Sailcappy
Well I would bet the switch/breaker on the back of the unit is nothing more than a main power breaker/switch disconnect. The maintained contact standby/active mode switch is in series with the rear panel breaker/switch. All amplifier loads are fed off this switch. The soft start circuit, along with, I would imagine active sequence staging start up, keeps inrush currents controlled from the voltage readings you supplied. A 3 Volt VD on a 50' 16/3 cord is incredibly low to say the least. Just curious is the multi meter voltage section reading true RMS? One other test I should have mention is to check the VD with the amp playing music from a dynamic music source with the volume level set where you normally listen to music. IF the voltage were to sag below the safety limits of the amp, because of the VD of the extension cord, the amp could be damaged. If you do the test watch the meter to see if it moves around with the dynamics of the music material. Hard to believe the dynamics of the amp does not suffer because of the 50' 16/3 cord....... The reason I ask is your friend qualified, confident, to perform work inside the electrical panel of your apartment? Nothing major.... Just move the hot conductor of the audio 20 amp dedicated circuit to another 20 amp breaker on the other Line, leg, bus in the electrical panel. (Providing there are any spares. If there is not a spare he could use a breaker that is being used, for the test.)
jea48
• He said all the wires are live coming in to the breaker box and it is not a good idea to switch them as there is no way to kill the current coming into the box.
Sailcappy
Your friend does not feel safe working on the inside of a live electrical panel and that is fine..... Better safe than sorry..... You would need to hire an electrician to do the test for you. Atmasphere, The Cary 7.250 has a built in DC blocker as well as a soft start circuit. Jim |
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. . |
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. |
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. . |
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. |
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?
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. . |
