Issue with Pioneer SX 1280 on AFCI circuit

micaiahm

Member
Anybody having an issue with plugging their gear into an AFCI circuit?

Last August I moved to a brand new place, which based on NEC codes has AFCI circuits in all living spaces. My Pioneer SX 1280's do not like this type of circuit. I hooked it up my first one exactly as I had in my previous residence which had been working for the better part of 1.5 years. (normally connected to Panamax 5400PM, PL-71 and HPM-100's) After 6 seconds, Protection Relay clicks and then keeps clicking on and off. Tried with components connected and with nothing connected. So I shelved it and used my Sansui au-7700 (which had no issues on this type of circuit) until I had time to get back to it.
A couple weeks ago I came across another minty 1280 and just had to buy it, had it rebuilt. Two days ago I plug it in and it has the same issue as my first one. With the above connected or nothing connected to it, the relay clicks at 6 seconds and then keep clicking on and off. Tried both plugging into Panamax and directly to wall, tried different rooms. Back to the tech it went yesterday morning where it proceeded to act perfectly, of course. Back home, same issue. Took it to my office, tried it with nothing connected, works perfectly. Connected to Office setup (Panamax 4300 PM, PL-71 and HPM-100's) and ran for an hour, no issues. Talked to an electrician at work and the circuits at work are normal 20 amp breakers.

Conclusion, I'm only having this issue on AFCI circuits.

Now I have two 1280's having the exact same issue. As I'm in a rental condo I can't change the breakers. Any suggestions?
 
Interesting, I think our code in Ontario, only have AFCI for bedrooms, but those e-codes are moving targets with sort of ridiculousness setting in as you are experiencing. I suspect it is the in-rush current is too high for the arc fault breaker. I have not investigated the trip current curves in AFCI breakers.
What to do however is more the issue. Yeah commercial is usually 20A circuits and 12AWG wiring, in a residence, it is 15A and 14AWG.
I guess you could double up and draw supply from 2 breakers/circuits instead of one, but that maybe a pain, as the other circuits are in other rooms. i.e extension cords = :(eek
Other option is surgery to the 1280 to change the peak in-rush current, but that is experimental.
 
At the risk of showing my electrical naïveté, would it make any difference to use a line conditioner?
 
Interesting, I think our code in Ontario, only have AFCI for bedrooms, but those e-codes are moving targets with sort of ridiculousness setting in as you are experiencing. I suspect it is the in-rush current is too high for the arc fault breaker. I have not investigated the trip current curves in AFCI breakers.
What to do however is more the issue. Yeah commercial is usually 20A circuits and 12AWG wiring, in a residence, it is 15A and 14AWG.
I guess you could double up and draw supply from 2 breakers/circuits instead of one, but that maybe a pain, as the other circuits are in other rooms. i.e extension cords = :(eek
Other option is surgery to the 1280 to change the peak in-rush current, but that is experimental.
The circuit is a 20amp breaker with 12/2 wiring. Haven't tripped breaker. The 1280 just keeps going in and out of Protection.
 
At the risk of showing my electrical naïveté, would it make any difference to use a line conditioner?
No problem. I am feeling a little lost on this one as well. I have a Panamax M5400-PM that I have used for the past two years. It provides linear filtering and regulation. I wonder if I will have to upgrade to a UPS, but before dropping another $1k just want to see if anyone has other ideas.
 
Is there anyway to slow down the soft start circuit or modify it so it's stable under these conditions? Seems to me it's what's tripping with the resistor NOT heating up and staying hot long enough and not staying energized long enough to allow the unit to start up normally, and not the spkr relay. The spkr relay and the soft start could be cycling due to undervoltage. Could the AFCI breaker be undersized as to cause an undervolt situation with a load on, (in this case the 1280) causing the 1280 to exhibit these symptoms?? I wonder just how many amps the 1280 draws during start up and during normal ops. It could be swamping the circuit breaker at startup and with the AFCI in it , the tolerances are too tight and the Arc fault is pulling off voltage vs a normal breaker which would allow for some overload before tripping

How about some voltage checks at startup?

RCS16. Am I blowing smoke out my ass or is this a possible scenario. With the unit on a normal 20A breaker'ed circuit, it apparently soft starts as designed and stays on without the protection relay tripping, which means all voltages that the Protect board see are normal and is happy. Seems to me that the AFCI breaker might also be faulty????? Possible????

File a complaint with the Housing authority and request an inspection of the circuit under loads, to see if the AFCI breaker is at fault. Plug in the 1280 to different circuits in the apt and see if the same thing happens, make sure it's the only thing on the circuit, no lights, nothing. Gotta keep those spark chasers happy and filling the AFL-CIO's coffers.

Hey it's a wild and crazy idea. :biggrin: NYC is full of them, so what's one more! ;)

I wonder if the 1980 with the same type of soft start would have the same problem?????????

Larry
 
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I don't think it's an AFCI. This is all localized to your apartment.
Different room = different breaker? But STILL the same AC power source.

Soft start is different than protect.

You need to hang an AC voltmeter on the AC power at the unit - Like perhaps the switched outlet in back. It may be a voltage drop, as well as everything else, the protect circuit senses the AC voltage at the unit (in the left channel main secondary AC to the big caps) for shut off.

If someone has a SX-1280 with easy access to the power cord, a variac, and an AC voltmeter, they could determine the "sweet spot".

You could also try a "line conditioner" to boost the line voltage a bit, it is a transformer that boosts the voltage at the line when it is sensed as low.
 
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Test: plug into an kitchen appliance outlet(closest to kitchen sink) or bathroom sink. They may be labled GFCI.
 
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Thanks Mark.

I went out of town last week. I will try what you were saying and post back here.

I have a Panamax M5400PM with voltage regulation and line conditioning that I am currently using, but still have the same issue when I plug into it.

I spoke to my building maintenance and electrician and they are going to come in and change the AFCI breakers out for new ones. At this point I can't convince them to give me regular. But they are curious about what is going on.

I will see if I can get a line on a variac I can borrow from someone close by. There has to be someone in NYC.;)
 
quick easy test ..share the same outlet with a standard lamp .. say 100w bulb if you can find one ..incandescent .. see if it dims whilst amp is trying to power up . if so the house power supply is dipping for some reason ..
 
Enough drop to momentarily trigger the low ac protection may not be discernible with just a lamp.
 
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Also one thing to check is to look at how the outlets are connected. If the romex is pushed into the quick connect holes, you might want to try and use the screws on the sides of the outlets. The quick connects have tiny areas of contact area where the screws are much beefier increasing the current carrying capability.
 
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Don't you have a DMM?

Something for everyone to remember is that the protection on a SX-1280 is implemented with a PA3004 chip.
That integrated circuit senses on it's pin 7 the AC voltage through a voltage divider (r10 1.8m, r9 680k, in > out = 27%) monitoring the pin 12 RED transformer wire that is supplying the raw speaker power (+/- 76 to +/- 65 V DC) for the LEFT channel.
it's a bit harder to figure out what makes it unhappy when compared to a transistor implemented protect circuit.

BUT the most important thing to remember is that protect cycling in and out does NOT cause additional current surges from the receiver
After 6 seconds it's all settled down, charged up and happy.
As long as the speakers aren't expected to BLAST.

Which is why I want the DMM measurements, so far done just from the outside of the unit,

BTW, were either of the tested SX-1280 units a multi-voltage unit?

Thanks Mark.
I spoke to my building maintenance and electrician and they are going to come in and change the AFCI breakers out for new ones. At this point I can't convince them to give me regular. But they are curious about what is going on.
Do you think they might be curious enough to TEMPORARILY, WHILE UNDER THEIR DIRECT OBSERVATION, to substitute a conventional breaker JUST LONG ENOUGH to test to see if the SX-1280 then behaves?
 
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He is in NYC. Electrical in NYC is about as nazi as you will ever get. (I apprenticed in the state which was almost as bad) Which in a way might be good that they have not burned down half a city basically wired in 1920. He might need an iso transformer to git er done.
 
Quad; According to the OP, he's in a brand new place (presuming newly built), presuming new wiring from the bldg's side of the bldg's internal substation. Anything is possible, Low system voltage, undersized wiring, undersized breaker, etc. When the 1280 cranks up, apparently the 1280's startup load is too much for the circuit and the voltage sags low enough to kick in the low voltage limit in the unit. While the 1280 is in the reset mode the voltage rebounds, and the 1280 starts back up after 6 seconds, the voltage drops, the low voltage limit kicks it out, and the cycle goes on and on. The breaker might be part of the problem, The feeder to the internal substation (main board or boards) might have problems, the boards may have loose connections or connections that were never tightened (gotta save $$ somewhere and pay off the inspector(yes I'm being sarcastic here but still.....)), something not connected, etc., etc., etc.,........... I'm not saying that this was or wasn't done, but the bldg was built by humans and some are less than scrupulous, some don't do their job, or falsify records. etc. It could be something as simple as a loose wire nut, all the way up to a defective part. Who knows at this point.

Micaiahm; Ask the Super and the electrician if the bldg's maintenance shack has a non afci or gfci circuit in the shack. If so, ask to take the 1280 down and see if it will fire up on that circuit. Check the outlet voltage with the DMM before and at the same time you crank up the 1280. If it does start up normally, then there is a problem in your apt./condo. If it doesn't start up, then the bldg has a problem. If your unit is a Multi Voltage unit, See that it is set to a higher voltage than that of the wall. For example if the voltage on the wall is 118vac, set to 120V, or 130V if it has one that high. DO NOT use 220-240V unless you use it on a dryer or Stove type circuit that is equipped for 220-240V.
 
These are arc fault interrupters. Since a typical breaker may not trip due to an arc, these are supposed to sense an arc and trip. They have had problems false tripping due to RF. Look at the device and contact the manufacturer. As far as the RF problem goes, a certain manufacturer and the FCC knows about this. I've heard they are now required in new buildings in a lot of places.
 
Let's remember that it is NOT the arc fault breaker that is tripping, it is the SX-1280's protection relay that is disengaging!!!

Which begs the question OF THE OP:
the relay clicks at 6 seconds and then keep clicking on and off

sequence:
power on
6 seconds later relay clicks in (normal delay period)

then what?????

re: on / off clicking: how many seconds on and how many seconds off? OR how many on / off cycles in a given unit of time (say, six seconds??)
 
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