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Amp Shutting Down, need help

I have a Cary 7.250 brand new amp that shuts down after 20 seconds in my NYC apartment. I have sent the unit back to Cary where it tests fine. I have tried the unit at my friend’s apartment and his place of work and it works fine. The unit is 100% in working order. After talking to many people I was told to attach a 50' extension cord and low and behold it worked.

The good news is that I have a dedicated 20amp circuit to this outlet. My voltage reads 118 volts and Cary said that is not a problem as the unit will work between 90 and 130 volts. I have tested for voltage on the negative lead to ground and there is no stray voltage. I have also tried the unit on other outlets in the apartment and the same problem occurs.

My mono blocks and all other components work just fine. So I’d love to hear suggestions as to how to get rid of this 50’ extension cord?

Thanks in advance.
sailcappy
jea48
4,533 posts
 
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.
.
metro04
222 posts
 
"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
jea48
4,533 posts
 
Uhhhh, yeeeaaah.... I was just seeing if you were paying attention. LOL!
08-23-12: Metro04
LOL....
.
Jim
sailcappy OP
57 posts
 
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.
almarg's avatar
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almarg
9,670 posts
 
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
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