Amp Shutting Down, need help

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

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

Now, how the hell are you guys (Jim & Al) quoting in small font?

Frank

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

08-11-12: Sailcappy
I have a Cary 7.250 brand new amp that shuts down after 20 seconds in my NYC apartment.

08-21-12: Sailcappy
Remember this happens AFTER [emphasis added] i go from standby mode to Active mode.

Jim & Michael (Swampwalker), I've been interpreting these and other statements to mean that if the power switch/breaker at the rear of the amp has been properly turned off while in standby mode, and the rear power switch/breaker is subsequently turned on, and subsequent to that the front standby/active switch is turned to on/active, then 20 seconds later the breaker trips (if the extension cord is not used). That is what I was asking Sailcappy to confirm, in question (1) in my first post tonight.

Would a good SPD, surge protection device, installed between the amp and the wall outlet shunt out the high voltage transients?

Don't know. The oscilloscope experiment I suggested might help answer that.

Frank -- click the "markup tags" link just under the box near the bottom of the page in which responses are composed.

Have to sign off now until tomorrow.

Best regards,
-- Al