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[Stephen Swaffer]

In my home wiring I prefer wiring the receptacles by just pushing in the wire instead of using the screw terminals. Is that acceptable, or will it really be better to use the screw terminals?

Most electricians I know that are concerned with a quality install refuse to use "quick-wire" push in connections.  I believe that the only receptacles now available with that connection are designed only for #14 solid awg wire-so as such are limited to 15 amp circuits.  I know they are UL listed and tested and that there have been improvements-but I have replaced too many that have been the culprit in a circuit that quits working-virtually every melted receptacle I have replaced has been wired that way.

In fairness, they used to be available and tested to work with #12 and that has changed (for good reason!).  If you choose to use them pay close attention to the acceptable wiring conductors-ie in my experience #14 SOLID only.   

My preference (when money is not an issue) is the ones that have a plate that clamps the wire-they are much easier to wire with stranded wire and even with solid you just strip a straight section slide it in and clamp the wire.  Even if you buy 30 receptacles and pay an extra 50 cents apiece that is only $15.00-if you need that many that is a drop in the bucket compared to your total investment.

[TJ (Tom) Cornish]

Thanks for all the replies so far. It's not that I have lots of ground loop or other noise problems. Those seem rare but still happen on some occasions. Usually I am quite happy with the noise floor of my system. What started this is that I will re-allocate older power strips from the band inventory to some other household duty. (Many of my belongings suffer from such promotions.) Usually the end of the life line is when the power strips are used for "seasonal" lighting. As such, I am now in a position where I do not have as many for the band as I prefer. This is when I started looking for new strips. Included in my research reading was a topic in this forum where the rep from surgex answered some questions. (Thanks Mike Sokol for setting that up) That started me down the path of convincing myself that I wanted to be MOV Free.

Based on some of the replies so far, it sounds like I should make several home made drop cords about 10 feet each using industrial grade duplex outlets. These will replace my stage power strips.

As to my Rack-O-Doom I assume this would be my mixing table with built in racks. (Maybe if I'm feeling real energetic I'll post a pic. I am proud of my work.) Right now it has a couple of JuiceGoose rack mounted strips + a couple more plastic strips. The plastic ones have wall warts and wall wart tails.

From their site: http://juicegoose.com/product-jg-jr.html
The Basic power conditioning includes a fast-acting metal oxide varistor (MOV) installed to clamp voltage spikes running between the incoming line and neutral leads. This level of conditioning also includes a capacitor to reduce the level of AC line interference that may be transmitted between the line and neutral leads

Are you suggesting that I remove all of my existing power distribution in my rack and replace with a dozen industrial grade duplex receptacles?

Thus it would eliminate any "cheap" power electronics and make for better connections.

In my home wiring I prefer wiring the receptacles by just pushing in the wire instead of using the screw terminals. Is that acceptable, or will it really be better to use the screw terminals?
(This would only be for interconnecting the outlets in the rack, not the drop cords.)

I'll definately consider the Amprobe INSP-3. I always use one of the cheap circuit indicator plugs. They may not always tell me when it is right, but I think it is reliable for the most common wrongs.

As to the Furman SMP products, I am skeptical only because it still has some MOV characteristics and does not satisfy the MOV Free mentality I had just before starting this thread.

I am guessing that if I still desire the aforementioned exercise, I can buy 1 or 2 units of surgex/etc and plug everything else into that. (1 for the stage and 1 for the foh for those times it is not on the same circuit.)

If anyone has some answers (even wild speculation is encouraged) to some of the actual questions in my first post, inquiring minds like mine still want to know.

Steve,

Surgex gear works as advertised, GFCI issues aside.  The big issue here is the unlikelihood of actually experiencing a surge of sufficient energy to actually cause damage - MOVs or not.  In the VAST majority of situations, Surgex and other SMP devices don't provide material protection because there isn't a material threat other than in extreme (and unlikely) situations.  Power supplies in most gear these days are universal voltage capable, meaning they are relatively unaffected by modest voltage spikes or brownouts without any help from a surge suppressor. 

The biggest risk you face is due to incorrect or poorly-maintained venue wiring.  This could be either a mis-wired receptacle, or a receptacle or supply wire that's loose (don't use the back-wire holes in your receptacles - spend the extra 20 seconds and screw them down.  You'll get a much better connection).  These scenarios are discoverable (other than the RPBG scenario) with the load tester Mike mentioned.  A Surgex unit (or any other surge protector) will do nothing to fix this.

The next biggest risk you face is probably low voltage due to cords that are too long and/or an electrical service that's too soft for the load.  At best you're not getting the full performance from your amps.  At worst, your digital gear reboots.  A Surgex unit (or any other surge protector) will do nothing to fix this.  Solving this issue requires moving your load to a better supply.  A fully-online UPS or a voltage regulator are workarounds, but the real issue is cruddy venue power.

Everything else that's left is small potatoes.  A Poor Man's Distro (http://tjcornish.com/articles/power-distribution-part-2--.html) is a really good idea.  Use rack mount strips if you want to.  If you're having noise issues or start to trip GFCIs, take your diagonal cutters to them and clip the MOVs out. 

[Mike Sokol]

My problem with "surge" strips is the actual name is a bit of a marketing lie. They really don't do anything to stop a "surge" which I define as a rather slow climb (10 milliseconds or so) in outlet voltage up to 2X the line potential, which can stay at this level for seconds (or until the gear blows a fuse or trips a breaker). For instance, opening up a neutral on a 240/120 circuit will allow the normal 120/120 split to do crazy things like a 40/200 volt split. That 200 volts probably won't be noticed by the MOV device in a "surge strip", but will certainly burn up any gear that doesn't have an automatic switching power supply. Another surge that I've seen is in older industrial buildings with 3-phase power that sometimes had undersized neutrals from the POCO transformers. I've seen lighting systems on one phase drag the neutral voltage around a lot, so punching a bunch of tungsten lights on one leg can cause a rise of 10 volts or more on another leg. I've personally measured the power to my amp rack jumping up to 130 volts whenever the leg of the lighting feed dropped to 110 volts. Again, a MOV device won't even notice that happening at all, nor can it do anything about it.

MOV devices should really be called spike protectors, since they do a reasonable job of shorting out microsecond rise-time voltage spikes that can sometimes reach 10 times the line voltage. Spikes can happen from collapsing magnetic fields in big motors when they're turned off by a switch or relay, and problematic in factories with lots of conveyor belt motors and such. Another spike generator is a nearby lightning strike to the earth. I personally had a cheap surge strip short out the internal MOV when a lightning bolt hit right in my front yard. My basement freezer was dead, so I thought it had been taken out by the lightning "spike". But lo and behold, the surge strip's MOV had shorted out and was tripping the internal circuit breaker, and the freezer has been running for another 20 years. But of course a direct hit to my house wiring would have blown up any MOV device and taken out a bunch of appliances, which is exactly what happened at my parent's house some 30 years ago and burned out all kinds of appliances and motors.

And surge strips won't protect you from getting shocked from an open ground (another old wives tale), nor will they reduce ground loop hum or hiss from poor gain structuring. As previously mentioned, you're better off having solid grounds and building power that doesn't sag under load. And don't forget the voltage sag/drop from long extension cords. If you're running more than 50 ft (don't we all) from the outlet, you should probably oversize the extension cords a bit so you don't throw away any more volts. So get rid of those orange Home-Depot 16-gauge cords and get some heavy duty 12 and 10 gauge extension cords for back-line and amp-rack power, even if you're just plugging into 20-amp wall outlets. Your gear will thank you...

[George Dougherty]

Mike, so the Furman strips with the 137V shutoff protection feature sounds like a good to have.  Do you know if Series Mode protection circuits do any better with any of those conditions, or is it really a voltage swing issue that skirts both types of protection?

[TJ (Tom) Cornish]

Mike, so the Furman strips with the 137V shutoff protection feature sounds like a good to have.  Do you know if Series Mode protection circuits do any better with any of those conditions, or is it really a voltage swing issue that skirts both types of protection?

The problem with both SMP and MOV-based units is that voltages high enough to trip those types of protection (gear is usually OK with a moderately high spike as long as it's very short) will still cause gear damage in a lost neutral or generator issue where the sustained (longer than 100ms or something) over voltage of those scenarios is as low as possibly 150volts.

In both the Surgex and Furman systems with over/under voltage shutdown, this is accomplished with a different circuit than the surge protection circuit.

Surgex/Furman SMP are fine for lightning, over/under voltage shutdown is a good thing, but doing extensive testing - including a load test - of your supply power is where most of your insurance comes from.

[Mike Sokol]

Mike, so the Furman strips with the 137V shutoff protection feature sounds like a good to have.  Do you know if Series Mode protection circuits do any better with any of those conditions, or is it really a voltage swing issue that skirts both types of protection?

Are you talking about their PST-8 strips? I've got Furman tech support on hold trying to figure out how these work before I can venture an opinion. If they have a separate voltage sensing circuit and a relay or crowbar Triac, then it could be good protection. I'll let you know what I find out from the engineering guy when he calls back.

[Frank DeWitt]

In our booth we replaced a bunch of plug strips with wiremold outlets connected to surgeX  They are expensive but always available on Ebay and the wiring is a lot easier using them.

Example  http://r.ebay.com/Tvx385

[George Dougherty]

Are you talking about their PST-8 strips? I've got Furman tech support on hold trying to figure out how these work before I can venture an opinion. If they have a separate voltage sensing circuit and a relay or crowbar Triac, then it could be good protection. I'll let you know what I find out from the engineering guy when he calls back.

Yes, those as well as all of the PL series 15A/20A rackmount units have Series Mode Protection as well as the Extreme Voltage Shutdown that trips at 137V according to the marketing material.

Thanks to yourself and Tom for the explanations of how these things work.  I'd read some general comments that most surge protection gear was near worthless while researching surge protection for IT equipment, but never found such in-depth info explaining why it was so.

[Mike Sokol]

Surgex/Furman SMP are fine for lightning, over/under voltage shutdown is a good thing, but doing extensive testing - including a load test - of your supply power is where most of your insurance comes from.

My son is getting his new video studio up and running in the next few weeks, so looks like we need to make a few videos about how to test house power using a Load Tester. I alreay have an Amprobe INSP-3, SureTest Analyzer, Extech CT-80 and a vintage Woodhead GLIT on my bench, so that would make a nice video series.

In the meantime, here's a link to the Furman EVS which looks like it should properly shut down the AC power if it goes over 137 volts. http://www.furmansound.com/swf/furman_smp_plus.html  I did receive an email from Furman tech support last night, and they're now monitoring this thread. They also supposed to call me back by tomorrow to confer on this a bit more.

[Steve Loewenthal]

OK Furman, please explain because I really want to know. Since the SMP products still contain an MOV, when the MOV shunts a spike to the ground, how is my other equipment with a pin 1 grounded cable protected from picking this up this redirected energy?

As long as you are at it, suppose the guitar player decides to turn up his amp past 11, causing it to explode and send a spike of energy back down the line. Will these products protect any gear in the next receptacle on the same Furman device?
I assume gear in an adjacent Furman device is protected. (where both Furman products are on the same circuit.)

Does the protection work the other way. Such as in the example above where the spike is generated by equipment plugged into the Furman device. Will the Furman device prevent this energy from escaping back out to the circuit? (Thus protecting equipment not even plugged into a Furman device.)

Lastly (for now) are these products grounded in such a way that putting 2 of them together, connected to different power sources, the grounds can be connected to make a (still not wealthy) poor mans distro. (Did Furman help us by adding grounding terminals to make this easier for us?)

[ProSoundWeb Community]