[schugh]

I've got three 20A outlets in my music/movie room.
The single one in the back is where most of the gear is (receiver, pre-amp, turntable etc).
It's on a separate fuse.

There are two 20A outlets in the front where my 7Bs are plugged in along with two REL R-218 Subs.
These two outlets I think are wired together somehow and go to the same single fuse in the fuse panel.

I turn on the 7Bs and then I turn on a REL and one or both of the the 7Bs go into protection for a couple of seconds before coming back out into normal mode.

At this point I can turn the RELs on and off as many times as I want and the 7Bs are fine.
If I turn off a 7B and wait just say less then a minute and power it on and then power on a REL, the 7B is still fine.
If I turn off the 7B and the REL and wait 5 minutes and then turn on the 7B and then the REL, the 7B again goes into protection.

If I plug a REL into a 15Amp outlet (not dedicated like the 20A outlets), the 7B is fine.
If I plug both a REL and a 7B into the same 15A outlet again the 7B is fine (does not go into protection).

I also tried plugging a REL and a 7B into the 20A outlet in the back where the rest of the gear is and this time the 7B does go into protection when I turn on the REL.

My dealer guy talked with Bryston and was told maybe the voltage is dropping below 95 for a bit as the 7Bs will go into protection then.
The guy came out today and we plugged in a multimeter and the voltage was a very steady 123V when the 7Bs were powered on and then the RELs were powered on.

So what could be happening here. Electricity wasn't my strong subject  in school 30 years ago.
What could be wrong with the 20A outlets (assuming there is something wrong with them?)

Thanks,

-- Sanjay

[*Scotty*]

When large power supplies consisting of a substantial transformer and a good sized bank of storage capacitors are first connected to the AC voltage the power supply can look like a dead short for several milliseconds.  Depending on the AC voltage swing which varies from zero to a nominal peak of 170volts, if the voltage happens to be at zero when the switch is flipped then the voltage drop will last long enough trip the protection circuits. A digital storage scope could see this short term voltage drop, the AC voltmeter sees the average AC voltage value.
Scotty

[Phil A]

Do you are the arc fault breakers?  I have two 15 amp circuits each on a single receptacle and a 20 amp circuit on its own receptacle where I plug my Torus RM 20 into.  My old 6BSST would trip the 15 amp circuit just over half the time and had no problems if I took an extension cord and plugged it into a 20 amp circuit.  It could be the voltage ramp up on turn on.

[schugh]

When large power supplies consisting of a substantial transformer and a good sized bank of storage capacitors are first connected to the AC voltage the power supply can look like a dead short for several milliseconds.  Depending on the AC voltage swing which varies from zero to a nominal peak of 170volts, if the voltage happens to be at zero when the switch is flipped then the voltage drop will last long enough trip the protection circuits. A digital storage scope could see this short term voltage drop, the AC voltmeter sees the average AC voltage value.
Scotty

I think I understand that. But what doesn't make sense is when I plug the REL and the 7B into a shared 15A outlet in the same room, the 7B never goes into protection.
Why would it to that on the 20A but not on the 15A outlet? The 20A outlets are dedicated outlets in the room.

-- Sanjay