Amp Shutting Down, need help

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.

.

Sailcappy, thanks for the additional info. A few things are not clear to me, though, which are along the lines of some of the questions Jim had.

1)If the extension cord is not being used, am I correct in understanding that the breaker on the amp trips 20 seconds after the amp is switched from standby to on/active (the rear power switch/breaker having been turned on previously)?

2)And when the extension cord is being used, will the amp play music during those 20 seconds, or does it really become active only after the 20 seconds have elapsed?

3)And as Jim asked, when the extension cord is being used do you hear the click of a relay at the 20 second point?

Regards,
-- Al

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

Hi Jim,

Yes, I did look at the manual. As you realize, though, it does not appear to provide enough information for us to infer answers to the questions in my previous post.

If the unit is in active mode and power is removed, it will remain activated when power is restored.

Yes, I noticed that both in the manual and in one of your earlier posts. But what I'm mainly looking to establish at this point is what the amp's normal turn-on behavior is, in the situation where the breaker had been turned off only after standby mode had been entered.

Which relates to your point about inrush current. It is not clear to me when the major inrush current normally occurs. Does it occur:

(a)When the breaker is turned on, assuming that the amp had been left in standby mode when it was previously turned off. Or,

(b)Does it occur when the amp is switched from standby to active? Or,

(c)Does it occur 20 seconds later?

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.

Just some thoughts.

Best regards,
-- Al

You know, as I read through all of this which is way over my head technically, I wonder, as I have from the beginning of this thread, why the OP uses the mag breaker as an on-off switch? And could that not be the major part of the problem? has the OP tried shutting down using the standby switch w the ext cord, and then leaving the breaker in the on position, plugging the power cord, sans extension, back in and again powering up from the standby switch? Perhaps he has and I missed it.