Amp Shutting Down, need help

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.

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