Amp Shutting Down, need help

Thank you again for your suggestions! I am being extremely systematic and it never hurts to hear that over again:)

• I have tried two different power cords, the polarity on both of the power cords is correct
• The outlet polarity is correct. I have tried 4 different circuits in my apartment and the problem still occurs.
• I tried with and without speaker cables including lamp cord.
• It seems that none of my outlets have separate ground wires. I will call Cary today to discuss.
• Remember the unit works perfectly with a 50’ extension cord attached. WHY OH WHY does this work?
• My gut tells me that somehow I am getting dirty (do you love my technical term) electricity which causes the Cary to feedback and trip the 15amp circuit breaker. Remember the circuit breaker trips after 20 second after the unit is powered on.

To be continued……

I plugged the Cary amp directly into the 20 amp branch circuit; with and without interconnects and with and without speaker cables. Nothing else was plugged in to the branch. The 15amp circuit breaker (which is the on off switch for the amp) blows after 20seconds.

When I attached the 50' extension cord it only goes to the Amp and it works. Nothing else was attached to the extension cord and it worlks when all my other audio gear is plugged in as well.

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?
.

Well, I'm out of ideas without being there - armed with test equipment. The fact that it works at Cary, and your friend's location(s), without the addition of extra impedance (wire length), clearly indicates some thing's up with your apartment wiring, or induced noise.

08-14-12: Sailcappy
"He also noted that none of my outlets in my apartment are wired to ground it seems the ground is left to the junction boxes alone."

By that, I assume your outlets and junction boxes are grounded via metal conduit per local code? I'd have a warmer fuzzy if I knew the LINE/NEUTRAL voltage or resistance, and would still contact Cary to enquire about any grounding sensitivity issues with their circuits. As far as the level of noise it would take to cause your situation, is most intriguing.

The fact that numerous people suggested adding a 50' extension cord is interesting as well.

Besides Jea48, maybe member "Almarg" could offer some suggestions.

If you do get it resolved, be sure to post your findings.

Good luck