Venue outlets have open ground. What does that mean?

[MidlifeBeginner]

I expect it is one like this:
https://www.homedepot.com/p/Klein-Tools-GFCI-Electrical-Outlet-Tester-with-LCD-RT250/313832938

 

[crazyBassClown]

I didn't mention earlier about the one-end-open shield link, but you're right, and if more firms made them like that, things would be better.

They probably don't make them like that because of the endless calls they would get about non working cables or cables that have "failed" according to the cable tester. Anyone who knows enough to know they need one can easily make their own.

 

[Old Garage-Bander]

Maybe you specified earlier which advanced tester you are using, but can you tell us (again)?

I neglected to mention which one it was, sorry. Ran down to the shop and grabbed it.

Actually it has only two lamps to indicate the state of the wiring. CORRECT and FAULT. It also gives more details about the wiring condition on the display. Possibly this would be easier for those who may be intimidated by sorting out what the lamps mean on the more basic three light tester.

It is a Klein Tools RT250. It came in a three pack with two other testers, a non-contact voltage detector and a leaded voltage tester. I think I got it at Home Depot.

Here is a link to the Klein Tools page. From there you can also link to the brochure for more details.
GFCI Receptacle Tester with LCD - RT250 | Klein Tools - For Professionals since 1857

 

[Old Garage-Bander]

I expect it is one like this:
https://www.homedepot.com/p/Klein-Tools-GFCI-Electrical-Outlet-Tester-with-LCD-RT250/313832938

Yup! That be the one.

 

[Old Garage-Bander]

Just a quick hint about having cables with pin 1 open on one end. I have certainly used those and made my own throughout the years. I also made polarity reverse adapters. On the outside, you can't tell what they are.
I would would use tape in the middle of a polarity reverse adapter cable, and put the tape on the lifted end of the ground lift cable.

 

[seamonkey]

Some of the newer outlet testers have voltage measurements built in.
[Invalid or Expired Link Removed]
Which can be important with gear that is voltage sensitive.
KAIWEETS KM117B American GFCI Socket Tester Pro with LCD Display
The display on this one is "Green" for good, "Red" for bad without reading the diagnostic chart.

 

[INSUB]

But, the only reason a GFCI cord would trip is if there was a dangerous situation, right? So, if I am understanding correctly, you wouldn't want the show to progress if that were the case.

As always... It depends.

If you are using a portable or receptacle GFCI and it trips, it's the equipment you plugged into it that is faulty. Which would be your own equipment. I think others pointed out earlier that using a portable GFCI on your own equipment wouldn't necessarily protect you from being shocked in the energized microphone scenario earlier because the mixer is not plugged into a GFCI as well.

Use of GFCIs can cause nuisance tripping in situations where no shock scenario is occurring. An example would be an amp that's chassis is correctly grounded but has an internal fault bad enough to trip the GFCI but not so bad as to stop it from functioning correctly and the fault is isolated from ground. In this case, the GFCI is performing correctly even though it is not protecting the user and thus disrupting the progress of the show.

So, no, a GFCI trip is not an absolute indication of a dangerous situation. Only you can use your best judgement as to whether the show should continue. Obviously, if the GFCI continuously and repeatedly shuts down the PA then there will ultimately be no show.

Portable GFCI use is required by OSHA for workers in the USA anytime an extension cord is utilized. The GFCI must be at the source end of the cord and should still be utilized if the outlet is GFCI type because it is unlikely that any permanently installed GFCI has been "Tested per the manufacturer recommendation" whereas a portable that is used & tested every day will have been.

I think we need to summarize the good insights from this thread into Electrical Safety Guidance for Bands.

• Don't create your own power cords. Buy commercial off the shelf. Pay attention to current/wattage rating.
• An outlet tester or surge protector with indicator lights will warn you about reversed hot or missing ground.
• Surge protectors only protect your equipment if they have a ground. Surge protection protects equipment, not you.
• A power conditioner or UPS might be desired to protect equipment or reduce noise.
• Your own GFCI is recommended to have along for outdoor gigs, or where drinks might be spilled on stage. A GFCI near you is better for protecting against electrocution than one farther down the wire.
• It is best to have all gear on the stage connected to the same grounded circuit. Ground differences cause noisy ground loops, and can shock you.
• If not using a wireless system, your guitar grounds you. Beware that PA systems might be on a different ground. Ground difference between your guitar and a mic can shock you. Ground lift on XLR systems are meant to cut noise, not protect you.

Those that are more in the know than I am can edit this, and make it a good reference.

Though the specifics may be a little off in this summary, I think you've compiled the gist of what's important to take from the conversation. We got a lot off topic over audio signals and noise because those are often created or exacerbated by poor grounding systems. I would like to correct a couple of points in your summary.

The GFCI location does not make it better or worse at protecting the person. Its proximity to the fault just makes it easier to troubleshoot where the fault is. Usually, people can figure it out right away when they plug in a faulty appliance that trips the GFCI instantly. When the tripping is intermittent or its cause is unknown, like a squirrel chewing wire in the attic, locating the fault is not so straight forward.

Ground differences do not shock people. People are shocked when there is a difference in voltage potential and the person becomes part of the current path whether that path leads to ground or not.

Nomenclature has been mentioned more than once. I can tell you that I have never heard of a GFCI referred to as an RCD or any separate device being sold for similar use under the term RCD. Perhaps my instructors did mention the term during apprenticeship classes, but no lay person uses the RCD acronym in the USA that I've encountered in 20 years. I had to look it up and wiki identifies it as an interchangeable name for the same device. I admit that to lay persons, the "ground fault" portion of the name can be confusing as it leads people to believe the fault is returning to the source over the equipment ground conductor. But it really means that the current has faulted to ground whether it returns to the source or not. This fault to ground is regardless of its path including the equipment ground or grounded conductors (neutral) and could be directly to the actual earth. In all cases the fault is considered to ground because the current is not returning to the source on the normal current-carrying conductors (hot & neutral or hot & hot depending on system).

One person mentioned the use of an isolation transformer. While this may solve noise problems, if the equipment ground is not extended to the load side of the transformer then you have just created a separately derived system that is ungrounded. This is not a safe practice. Most industries that used ungrounded electrical systems are changing those systems to be grounded due to danger of electrocution and fire. I would assume that most, if not all, consumer-grade, plug-in isolation transformers are not creating ungrounded, separately derived systems. I don't think recommending use of isolation transformers to people who don't know how to implement them safely is prudent advice. Nor should use of such device be necessary equipment for musical performers.

Ultimately, it should, and legally is, the venue's responsibility to provide a safe work environment regardless of if those workers are permanent or temporary and to their guests as well (patrons and unpaid performers). But we have to find a way to protect ourselves too. The portable GFCI is our only reasonable recourse against a faulty venue electrical system in the moment. You can notify venue and refuse to play night of or in the future if not remedied. Where I live there are limited venues to play. All of them probably equally oblivious to electrical safety and ignorant to their responsibility of keeping all occupants safe from the building.

 

[crazyBassClown]

I also made polarity reverse adapters. On the outside, you can't tell what they are.

I have a few of these and find they make it easy to tell when something is phase reversed and similar cost to making a custom cable.

 

[MidlifeBeginner]

we have to find a way to protect ourselves too.

Please do take my list, make corrections, and repost.

Just keep the list easy to follow. If we fill it up with too much technicality, it won't get read.

Might be worth adding something about how to safely change tubes.

Ground differences do not shock people

Ground differences are voltage differences. Yes, the bigger problem is if hot and neutral get reversed somewhere. Old equipment often connects neutral to ground. So, ground difference is line voltage.

 

[Geogio]

The Furman...
My response was in regards to chasing down some noise on the circuit. Running single coils I use a shielded cable and I use the Furman and it does help. I do not use the Furman as a safety device. I always check the outlet for ground with a tester and if there are any Outlets that are bad around the band I find one that's good and we will usually use one or two that check out.

 

[TomB]

Fortunately, between SMPS and digital lighting, the loads on stage today at any moment are a fraction of what they used to be, all of which allows more equipment to safely connect to fewer circuits; helpful if you only trust one or two of them.