ECN Forum Forums General Topics of the Trade General Discussion Area Regulating voltage

Can you move the problem loads to the other leg of power?

It sure sounds like you're on the same phase.

Trading breakers... that is moving your circuit load from A phase to B phase might be all that you need.

As ever, double check your neutral and ground bond. You want that sweet.

Also look out for bad make-up and or corrosion, especially along any path to motor type loads. Until back-EMF kicks in they can pull the voltage down. Poor connections in such a situation operate as a choke and cause the pull-in period to lengthen. The extra PxT shows up as hot spots along the path.

All of the above is cheap to check out and is far more likely to solve the problem.

Whew, thanks for all the replies guys! I did some further testing with my multimeter and this is what I found:

The readings that I stated earlier (114-122 volts) were what my UPS was saying, but my Multimeter doesn't seem to register such huge differences.

I saw a 3 volt drop phase-phase at the panel when turning on the dryer. After the initial startup it settled down to 1 volt drop. Phase-neutral was similar.

I saw a 5 volt phase-neutral voltage drop at the Amplifier when turning on the dryer, and then it settled down to about 3 volts drop.

I am now fairly certain that it is simply an issue of the Amp being over sensitive. I took it into a high end audio shop and they could not replicate the problem, however their power was very stable (no large loads turning on or off).

I should provide a few more details on the Amp, and clarify what I mean by "clipping". It is not clipping in the audio term (when you turn the sound up above what the amp can handle). I believe it is the toroidal transformer making a clicking sound (it always does when I first turn it on). When it makes the clicking noise the audio stops for 1-15 seconds.

Some more details on the amp:
The amplifier is a Sugden A21a Class A Integrated Amp. It's output is 25watts per channel at 8 ohms and it draws about 1.2 amps (more when its warmed up and music is playing). The unit is hooked up to a line conditioner (Monster Power HTS1000 MK I, which is supposed to be decent), but that makes no difference.

Here are some power specs on the Amp:

"Transformer Triple Secondaries 1-For Phono/Line Stage 40VA 2-One for each channel 60VA each
Main Capacitors Smoothing 1 x 10000uf 50volt per channel Output decoupling 1 x 10000uf 50volt per channel
Power Supply Single ended voltage rail
Output Devices 2-multi emitter NPN per channel
Circuit Single ended Voltage rail
Push Pull output stage All stages emitter follower Cascoded driver stages to give maximum phase shifts. All capacitors used in signal path are high-grade electrolytic (similar to Black Gate) Resistors are 1% metal film with metal oxide emitter follower resistors.
Specification Line input Frequency response 6Hz - 31kHz 30Hz Separation -62dB Noise -77dB Distortion 0.01% 0.01% Sensitivity 150mV 3mV (MM) 0.2mV (MC) Dc offset 5mV Power output 25Watts per channel pure class A"

Unfortunately putting the Amp on a different phase is not possible as all of the loads that cause a problem are 220.

I did notice that the ground cable from the poco is hooked up to the ground, and the ground cable from the rod is hooked up to the neutral, however I dont think this would make a difference? The ground and neutrals were both tight in the main panel, I have yet to go around and check all of the baseboard heaters/appliances/junctions/etc... That will probably take me some time to do.

I have a feeling that purchasing a Voltage Stabilizer or a Online UPS would do the trick, but I havent found anything for under $1000 yet, so I'm going to try everything else I can.

On a side note, I did take the Amp down to another building on the property (newly wired building/new 400 amp service/new transformer) and it had the same problems, however the only load I could test it with was a 34 amp motor (220amps startup) so it probably wasnt a very good test.

Again, thank you for all of your responses, any further insights would be appreciated.

-invictive

Do you have a scope? I think your problem is inside, not outside the amp. I bet you have a marginal power supply.
I would start by watching the power rails for ripple. It might just be a bad filter capacitor.

Yeah Greg, I agree. I am staring to think that the problem is internal to the amp as well. It seems as though the extra loads cycling on and off is perhaps just a simptom rather than the problem itself.
I know that class A amps are rather demanding of thier power supplies, so I would be inclined to check there first.

I'm with Greg on this one. Your amp should have a nice power supply that would include DC voltage regulators after the transformer and rectifier. The regulators, along with the filter caps, should give you plenty of stabilization within the AC voltage swings you are seeing.

LarryC mentioned that you should tighten your connections at the service and throughout the panel to try and alleviate the issues with your power service, and I agree. This is the first step in diagnosing a voltage fluctuation, as it is cheap and very common cause of the issues you are describing.

If the problem persists with the voltage swing, I would contact your PoCo. They may have a loose connection at their transformer as well. At the very least, they can put a data logger on the circuit and see if the problem is on their end.

Good Luck!!

Bad filter caps in a power supply? Bah, those things last for decades and NEVER fail.

I think the real problem is that you need gold plating on your panel bus bars and Monster brand wire to a special new audio-grade receptacle.

https://www.electrical-contractor.n...1/Receptacles_for_Stereophiles#Post66551
https://www.electrical-contractor.net/forums/ubbthreads.php/topics/67554/1
https://www.electrical-contractor.n...8952/499_Denon_Ethernet_cable#Post178952
https://www.electrical-contractor.n...ics/160643/oxygen_free_copper#Post160643

Get all that stuff, and your amp will sound like a million bucks!

Hahahaha, I love how much audiophiles waste on all that silly gear.

You'll always see things like: "I didn't notice any difference at first, but after 30 hours it sounded much better!" Duh... you just got used to the sound and convinced yourself it sounds better. It's all a placebo effect...

Don't even get me started on Monster Cable, I could rant for days about that crap.

I'm planning to take the Amp to a friends place this evening, hopefully he can take a look at it with his scope.

-invictive

My bet is the ripple is dipping below the clip level of the regulator so some gets through. With a higher voltage it all gets stripped off.

If you had 3 volt drop phase to phase at the panel when turning on the dryer, how can you have a 5 !! volt drop at the amplifier recepticle when doing the same thing? The only thing that makes sense is that the dryer has a large 120 V load and the dryer neutral connection is poor.

Invictive: Does the dryer have a 3 pin or 4 pin plug?

I still feel that the issue is in the house wiring.

Larry C

Larry:

The dryer is properly wired, it is a 8/3 cable/40 amp breaker.
I have yet to check the neutral at the dryer, however it is not just the dryer that causes the clipping. Any large load will cause the amp to clip (baseboard heaters/stove/etc).

On the weekend I am going to do a thorough check off all the connections in the house. And I am still hoping to have the PoCo come out and install a monitoring device, just to be sure.

Hey, maybe this would help me! http://www.lessloss.com/lessloss-firewall-power-distributor-p-196.html only $5000, hahaha.