View Full Version : How To Make A Powertap Power Tap
22nd June 2005, 01:08 PM
I have recently acquired some exceptional lighting effects for our band. We're moving towards self-sufficency and have bought a lot of our own gear.
That being said we're running into power related issues. We keep blowing fuses and the companies we were renting lights and sound from had what they called a power tap. I can't find a schematic of one on the web and I've asked three friends who are master electricians to help.
They said they'd build it for me if I could tell them exactly what it was...
Can I get some help from the forum. Here are my light specs:
2 Trees (Front)
4 Par 64s on Each
1 S100A Strobe on Each
1 Crank Truss 10' (Back)
4 Arc 150 Intelligent Lights
16 Par 38 cans across the top of the truss
8 Par 64's
2 S100A Strobe Lights
1200 Watt Fogger
Each tree has a DMX dimmer pack
The Truss has three DMX Dimmer packs
1. How many amps should we build this thing for?
2. Guage 10 Romex is that a good spec cos' I can't find 8?
3. Do we create multiple 20 amp breakers for the gig on this power tap?
4. What do you plug into the breaker box?
5. Anything else I should know? BTW, No international shows and I'm in the USA.
22nd June 2005, 01:12 PM
is a powertap the same thing as a reusable fuse? For heavy power grids you can get switchable fuses that just switch off instead of burning out. These babies are real moneysavers if you got a lot of powerouts...
You should NOT make your own switchable fuse!!!
or perhaps a powertap is the same thing as "tap switches"? if so it will not help you prevent power outs and you should not make one yourself as this is high currency gear and heavily regulated, in norway...
22nd June 2005, 01:56 PM
Is it distro?
ie 63A plug going to trips breaking down to 32A and or 16's?
You need to work out how much power you need to run it all. Add all the watts up and divide by your voltage to get amps.
Be aware if you make it you will be liable if it kills anyone.
Also strobes only draw when theyre on and par cans are rarely all on at once, something to bare in mind in small venues which may not at first look have enough power, you just have to be careful with your levels.
Id speak to a proffessional if I was you.
23rd June 2005, 11:31 AM
As understand it, a power tap is not the same as a distro.
A distro takes high ampage power and provides seperate lower rated sockets for equipment to be plugged into.
A power tap is basically a trick for efficiently getting 220V power in counties where power is usually delivered into buildings as two 110V circuits. This is the case in the USA.
The power tap is connected to sockets on each of the two circuits. Once this is done, it will combine the two 110V supplies to make a single 220V supply.
From what I'm told, a power tap is not something you want to get into building yourself - they need all kinds of failsafes in order to be safe. Also, if the building distro has any kind of earth feault detection, the power tap will trip it.
What you really need to do is get a decent distro (either buy one or have someone with good electrical qualifications build one and sign it off) and make sure you connect it into a sufficiently highly rated circuit at the venue.
Venues will usually have lower rated circuits with domestic-style sockets and higher rated circuits (usually 32A or 63A in Europe) with different sockets. If you're using lots of lighting, you really need to be taking your supply from an outliet that is designed for stage equipment rather than one that is designed for the cleaners to plug their vacuum cleaners into.
1st July 2005, 08:24 PM
I wanted to follow up with this because even basic information is hard to find out there===like a secret cult of electricians. When we first started asking guys from the local electrical contractors union (I'm a contractor myself and know lots of guys in the biz)....
most of what I got was I've never heard of that special application, but I'm sure I can build it if you tell me what you want....
As for distro vs. tap....here's the deal...
We're using furman $1200 power distribution circuits that have isolation transformers in them and take care of cleaning the power for us really really nice. That's not an issue. We're rated to 120amps on them....plenty for our show!
When talking about Power Tap what it is essentially is the ability to plug into a bar/club's power service between the service box and the power meter. Many clubs are rated to 80amp or 100amp service. The newer ones have their electricity spec'd out to 120, 180 etc.... becuase they're having bands like ours in and nice stages...
However, since we're usually needin between 40 (no lights) to 100 (full load) amp serivce this works against us when trying to get that working just the right way! In fact we have a hard time if the club is only wired for 100AMP service and they stil lhave to run their beer concessions and refrigeration, lights, electriciity, and the like. This is where a power tap comes in.
Consider a power tap another 100AMP service on the same lines coming into a club. Bands using thousands of watts of power and light need one. Every company we've rented lights/sounds from uses it for us. I've seen them all over but with the recent purpose of a lot of our own gear, we're needing to make/find one of thses....
We can not buy one commercially so we've had to have an electrician make one.
It's a basic cicruit breaker box with multiple circuit breakers all made to code with a 100amp service master at the top. The power taps into the main electical line in multiple ways.
The most expensive aspect of this was the cord. We have to have a long run and 10 Romex has been working great (double run for redundancy and protection!) $1.80/ft.
Everything else is standard. From the circuit box we have 6 20 AMP circuits coming out of the breaker box. Each of these has 4 standard US 115VAC service.
The PA and the instruments are all plugged into the Furmans as above cleaning up our power if its dirty from the tap and keeping our investment safe.
We use 20ft' custom made 10 guage cabeling coming from the plugs to the instrumentation as power snakes and they work out great! Nice rig. Works out great!
That's the skinny on what you need to know. Yes, get a professional electrician to do this. This is very very very mportant so that your product is built to local code and that its spec'd out so you don't kill yourselves, your tech, or burn the club down. No one in our rock band wants to be a Great White at least!
As always, I hope that this helps other people understand because looking for power taps on the interenet hasn't born out any fruit and understanding that a power tap is like a service upgrade for a club is an easy way to explain this special application to your local electrician. its like running 100AMP service in parallel...100AMPS to the club already up to code and your 100AMPs to the band also up to code.
I'm not sure the spec's in GB, FR, or GR but hey this works well in the US.
1st July 2005, 10:18 PM
When you are talking about bolting on to power mains you need an electrician (with insurance!) 100 amps requires #1 or #0 cable [American gauge system AWG], even thicker for longer distances or high temperatures, with a tough layer of insulation to protect it from the road. [you must have mistyped using #10 Romex - that will not work - 10 is too small and Romex is too delicate] The electrician needs to give some serious thought to grounding as well. Residential and commercial breaker boxes aren't really designed to get banged around on the road. No free drinks for the electrician - they need to unbolt the cables after the show!
These guys in SF are experts and sell boxes of their own road tested design http://www.hughstonengineering.com/
The use of power conditioning transformers is a nice touch - very professional.
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