Breaker Panel Tie-in... What is the CORRECT way to pull power?

Re: Breaker Panel Tie-in... What is the CORRECT way of pull power?

Tim Duffin said:
I'm confused a bit here. I know that its "PC" to always say "Have a licensed electrician do anything." But how many of you guys actually have an "electrician" tie in the power for you? Only at union venues is there an electrician present, and most outdoor venues with a generator I end up being the one doing the tie in because I don't want it done wrong. I have challenged an "electrician" who didn't believe that there are generators with 139V outputs instead of 120V. When I showed him that the generator he rented was for mining equipment and not for sound he balked and said that it must be a "typo" because theres no such thing as 139v...

I have difficulty trusting people around the power for my system.
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I've rarely done a show in a union venue, and nearly all my power tie-ins are done by a venue electrician or a contracted electrician.

Most (real) generators have variable voltage within a certain range. If it's putting out 139 volts, turn it down!

Of course, my dad is a commercial electrician, and often provides the tie-in service for me :)
 
Re: Breaker Panel Tie-in... What is the CORRECT way of pull power?

hmm... so you have never seen a 139v generator?
 
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Re: Breaker Panel Tie-in... What is the CORRECT way of pull power?

Jay Barracato said:
Tying into a generator that is not part of a structure is a little different story, but the one generator company I have experience with does that as part of the delivery, so that has not been a problem.

I do carry a meter and double check what is provided.
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I tend to be equally, if not more critical about work done by others regarding generators, especially outdoors. I've discovered a few outdoor rigs up & running with no proper "earth" for the roof, deck OR generator.

R~
 
Re: Breaker Panel Tie-in... What is the CORRECT way of pull power?

Royce Covington said:
I tend to be equally, if not more critical about work done by others regarding generators, especially outdoors. I've discovered a few outdoor rigs up & running with no proper "earth" for the roof, deck OR generator.

R~
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Now this got me thinking...

How would you check for proper grounding of the stage and roof? What would you visually see (tie in to generator ground or separate ground rod)? What would you meter?

In the past I have checked conduit in buildings as a ground path by metering hot to conduit.

I have never provided more lighting than a couple of trees, and I have no plans on ever being the person responsible for providing staging and roofs; however, I would like to know how I can best inspect the work of others to ensure the maximum possible safety for the bands I represent.
 
Re: Breaker Panel Tie-in... What is the CORRECT way of pull power?

Royce Covington said:
I tend to be equally, if not more critical about work done by others regarding generators, especially outdoors. I've discovered a few outdoor rigs up & running with no proper "earth" for the roof, deck OR generator.

R~
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Ground for the roof and deck...may or may not be necessary. Check the local codes.

Some Generators do not need to be grounded to earth, check the local codes, especially in California.

Hammer
 
Re: Breaker Panel Tie-in... What is the CORRECT way of pull power?

Tim Duffin said:
I'm confused a bit here. I know that its "PC" to always say "Have a licensed electrician do anything." But how many of you guys actually have an "electrician" tie in the power for you? Only at union venues is there an electrician present, and most outdoor venues with a generator I end up being the one doing the tie in because I don't want it done wrong. I have challenged an "electrician" who didn't believe that there are generators with 139V outputs instead of 120V. When I showed him that the generator he rented was for mining equipment and not for sound he balked and said that it must be a "typo" because theres no such thing as 139v...

I have difficulty trusting people around the power for my system.
Click to expand...

All of the municipalities I provide for have a city engineer come hook up a panel for me. The panels are all new, designed by me..; )
 
Re: Breaker Panel Tie-in... What is the CORRECT way of pull power?

Tim Duffin said:
I'm confused a bit here. I know that its "PC" to always say "Have a licensed electrician do anything." But how many of you guys actually have an "electrician" tie in the power for you? Only at union venues is there an electrician present, and most outdoor venues with a generator I end up being the one doing the tie in because I don't want it done wrong. I have challenged an "electrician" who didn't believe that there are generators with 139V outputs instead of 120V. When I showed him that the generator he rented was for mining equipment and not for sound he balked and said that it must be a "typo" because theres no such thing as 139v...

I have difficulty trusting people around the power for my system.
Click to expand...

I don't trust people around power for my system either. Thats why I carry a meter and check it before I plug anything in.

I don't tie into other peoples panels, and i meter everything before I plug anything in.

14-50R - meter it before I plug in. Meter my distro after I plug it in. Throw a load on it. Meter it again.
Cams/tails, Meter the cams when tied into my distro. throw a load on it. meter it again.

Just because I know enough to do it doesn't mean I should. A job is not worth my life or the people at the events lives. Also my insurance doesn't cover it.
 
Re: Breaker Panel Tie-in... What is the CORRECT way of pull power?

Scott LaRochelle said:
Are you serious? Why would this be? Every time I use a genny, just yesterday as a matter of fact I pop two ground rods in the ground...
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NEC permits portable and vehicle-mounted generators with outlets mounted on the frame of the genset to be used without external grounding electrodes. See 250.34
 
Re: Breaker Panel Tie-in... What is the CORRECT way of pull power?

Tim Duffin said:
I'm confused a bit here. I know that its "PC" to always say "Have a licensed electrician do anything." But how many of you guys actually have an "electrician" tie in the power for you? Only at union venues is there an electrician present, and most outdoor venues with a generator I end up being the one doing the tie in because I don't want it done wrong.
Click to expand...
The choice is up to you but it's not just PC, in many cases there are actions related to electrical systems that by law are supposed to be addressed only by licensed Electricians. The intent of such laws is to try to protect the public, not your equipment, and if you perform such actions you are not only assuming liability, you're also opening yourself up to claims of practicing Electrical Contracting without a license, the latter even if everything is done properly. And guess what that might do in regards to your insurance coverage and rates?
 
Re: Breaker Panel Tie-in... What is the CORRECT way of pull power?

Well I am still following the conversation, but this has turned into our best traveled thread.
 
Re: Breaker Panel Tie-in... What is the CORRECT way of pull power?

when i first started doing sound lo these 20 plus years ago, i decided that tieing power was my 'line in the sand'. over the years, i gradually learned enough to probably do the job myself most times. and i've waited around for hours waiting for electricians to tie or untie tails. but i always kept that line in the sand because i wasn't sure i knew all i thought i knew.

today i learned about 139V 'mining' generators... wah? 25 years doing this and i've never heard of such a thing...

and this is why i won't do tie-ins myself. ever.
 
Re: Breaker Panel Tie-in... What is the CORRECT way to pull power?

All electrical work regarding tie-in's should be done by a licenced electrician. However when you are on the receiving end of such a supply it is good practice to know the code, what is legal what is not, and how to best guarantee your safety and compliance. This will give you the ability to identify potential problems before a life is lost. Most importantly would be learn how to use your meter correctly. It is your best tool to identify illegal/unsafe connections before you blow up your gear or even kill an innocent bystander.
Cable is protected by the upstream breaker. This breaker must be the correct value for the size and grade of cable it is protecting. Everytime you downsize cable you need another breaker. Observe the electrician that is tie-ing you in. Ensure he correctly tightens your hots, neutral and earth. Many problems arise with loose electrical connections. In these situations it will often meter correctly, only giving a problem when a load is connected. You will have seen melted plugs and fittings. Often this is caused by loose connections causing arc-ing, which introduces a lot of heat to the surrounding area (that's how arc welders work) When connecting and disconnecting cams, ALWAYS connect earth, neutral, hots; disconnect the opposite way. An electrician here (who specialises in our industry) mentioned that even cams should be energised by a licenced electrician, given the currents involved and the ability to miswire.

Hopefully we are providing some good practise for those who should know exactly how to deal with the larger power supplies required by our production equipment.

Here in New Zealand we have 240v Single phase outlets domestically. 3 pins; Hot, Neutral, Earth. The advantage to the higher voltage means our single outlets supply most items fine. ( A 'dryer plug' is unheard of here) Once we move up to three phase we have 32A 400v system on 5 pins; 63A 400v on five pins; and then into camlocks/tie ins. You can run a sizable system off a domestic outlet, and tie-ins don't really exist untill you get into line-array scale shows. There is another standard, found in workshops for welders/tools etc that has three hots and an earth. At a 32Amp level it is the same plug, just without the neutral centre pin. We did a show in a empty commercial warehoure. SOMEONE HAD DRILLED THE CENTRE PIN HOLE OUT OF THE OUTLET!!
As a result, our five pin three phase plug fitted in just fine; un-known to us that we had no neutral. Popped the protection resistors on a rack of Lab.gruppens. Thankfully that was all that was damaged but highlights an example where illegally modified outlets and NOT METERING before you plug in can seriously spoil your day.


DISCLAIMER: I AM NOT AN ELECTRICIAN. I DO MY BEST TO BE AS INFORMED AS POSSIBLE ABOUT ALL RELEVANT AREAS OF OUR INDUSTRY, FOR THE SAKE OF SAFETY AND INSURANCE.
 
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