Pub power points

roundthebend

You know the deal, turn up at the pub and there's a double socket about 3m away and nothing else. You've got 2 guitar amps, bass amp, electronic drum kit, mixer, 2 wedges, 2 tops, sub, lights....

How do you sort it?

Basically, should I daisy chain extension leads together? Or get a pair of 6-way extensions and then some longer power cables?

Stratavarious

We have a couple of 6 ways on long leads that provide a dozen sockets up to 5m from the sockets. We also have 10 and 30m reels but don't use them unless we need the distance and can avoid too much load with them coiled.  We will use them to get to distant sockets to spread the load. 

You can get newer 6 way extensions with USB too for charging iPads or cameras.. we have a digital mixer.

There are also some neat 5m long double output IEC splitter cables in the lighting kit which are great for tops and LED PAR lights on the stands or amps/rack/mixer and avoid chaining multiways or reels.  HIGHLY recommended if you have gear that uses them or sits close together.

https://cpc.farnell.com/pro-elec/pe01093/lead-uk-plug-to-2x-iec-c13-skt/dp/PL13332?st=iec%20splitter

Velcro cable ties are also useful for tying up cables above doors, etc. as well as coiling long power leads.

Extras include circuit breakers. Have a cable cover too if we need to get across a walkway or emergency exit,  https://www.screwfix.com/p/d-line-cable-cover-light-duty-floor-cable-cover-1-8m-black/9345F?kpid=9345F&ds_rl=1249401&gclid=CjwKCAjwge2iBhBBEiwAfXDBRxv9oGa1nrfSZZ5yL7g6yNF1psBBjnB0Og0s_vJB-jE7ntvUKqqdYxoCPzgQAvD_BwE&gclsrc=aw.ds

Roland

With main cables you need flexibility to cover different venues. We carry a selection of 4way and 6way distribution boards, plus two mains reels for longer distances. Typically we will have a distribution board under each PA tripod to power the speaker and lights, and a 4way for each player. How they’re connected depends on the venue.

I’ll put in a word for using a socket tester before plugging anything in. I’ve seen unearthed sockets, and sockets with earth and neutral swapped

Danny1969

Just remember when daisy chaining that the first 4 way plugged into the mains socket needs to be capable of handling the combined current of what all the other 4 ways are drawing through it.  So 13 amps are more useful than 5 amp extensions. 

If you buy reeled extensions then they need to be unwound before you draw a big current through them. 

CPC do a range of black 6 ways which look better on stage and are more useful than 4 ways. 

Musicwolf

I got this from B&Q several years ago (I don't think that it's available anymore), cost approx £25.  It must be a least 10m long and it has 5 single sockets on short spurs spaced about 1m apart.  We run it across the back of the stage then use 4 or 6 way extensions on 2m cables to distribute power to where we need it.

One of the best things that I ever bought.

fastonebaz

Daisy chain 4ways and reels and hope for the best. 

Jalapeno

Roland said:

I’ll put in a word for using a socket tester before plugging anything in. I’ve seen unearthed sockets, and sockets with earth and neutral swapped

This. Muchly.

roundthebend

Danny1969 said:

Just remember when daisy chaining that the first 4 way plugged into the mains socket needs to be capable of handling the combined current of what all the other 4 ways are drawing through it.  So 13 amps are more useful than 5 amp extensions. 

If you buy reeled extensions then they need to be unwound before you draw a big current through them. 

CPC do a range of black 6 ways which look better on stage and are more useful than 4 ways. 

Good point about the first one needing to handle all of the combined current. So, how do I get a figure for that? I know it will vary depending on what's plugged in, but let's say I've got a 40W valve amp, and a pair of active PA speakers that are rated 600W peak.

roundthebend

Power = Current x Volts (P=IV)

Where UK mains is about 230V (RMS) then my 600W active speaker will draw about 2.5A (RMS). Is RMS all I need think about? My PA speakers actually state 200VA power consumption, which sounds like 200W to me. So, that's only 0.87A.

Danny1969

VA is a way of averaging the RMS of the current as well as the voltage ... useful for spec'ing fuses and such. 

Audio waveforms are actually incredible complex so working out the current draw is much more complex that it would be with a simple resistive fixed load. Generally though the max current draw will be 10 to 20 % more than the rated output for class D SMPS driven active speakers and 25 % 40  ish more with linear supply and AB amplifier / active speakers. 

Easiest way is to use 13 amp 4 or 6 way extensions  from back of the stage running in both directions off a double socket or more than one socket round the sides to the front of the stage. So 2 x daisy chains not one long one. 

For most pub gigs the current draw isn't actually a lot. But outside that seemingly small increase of volume required actually involves 3 to 4 times as much current draw due the log nature of our hearing. Thats when it's very important to unwind reels and think about what 4 ways are being used. 
I did a corp gig outside once where the hire guys didn't unwind the main feed for the event off the reel and the whole reel got so hot the insulation melted together destroying a £400 cable reel

roundthebend

I've witnessed a coiled cable melting when used with an outdoor IR heater.

Jalapeno

Been laughed at before for unspooling mains coiled leads

ScreamingDave

Another point is to be wary of using an RCD. They’re great, but if the venue has a new-ish consumer board it will have and RCD built in and two RCDs in the same line will fight with each other and one will keep tripping, even though there’s no fault

ICBM

roundthebend said:

You know the deal, turn up at the pub and there's a double socket about 3m away and nothing else. You've got 2 guitar amps, bass amp, electronic drum kit, mixer, 2 wedges, 2 tops, sub, lights....

How do you sort it?

Basically, should I daisy chain extension leads together? Or get a pair of 6-way extensions and then some longer power cables?

You can run up to 6KW from just one double wall socket, so for most pub bands it shouldn’t be an issue, especially with modern lighting.

It’s best to use a ‘tree branch’ arrangement not a ‘daisy chain’, ie one heavy-gauge 13A-rated 4-gang plugged into the wall (x2 if it’s a double socket), then four more which can be 5A-rated plugged straight into that, rather than a sequence of them across the stage with some amps etc and the next 4-gang plugged into each. That minimises overloading the ones closer to the wall - the UK fusing system is well-designed, and as long as all the extensions have the correct fuse you can’t blow anything. If you need more than 16 outlets (or 24 if the lighter-duty ones are 6-gang), then tree-branch again as long as the one you’re feeding it from is also 13A.

roundthebend said:

I've witnessed a coiled cable melting when used with an outdoor IR heater.

I’ve seen one melt when a band ran everything through it too.

PrecisionGuided

The Brennenstuhl hugo! 4, 6 and 8 way polycarbonate jobbies (CPC / Amazon) are very rugged and reliable

Hoof

ScreamingDave said:

Another point is to be wary of using an RCD. They’re great, but if the venue has a new-ish consumer board it will have and RCD built in and two RCDs in the same line will fight with each other and one will keep tripping, even though there’s no fault

No they won't. RCD's trip if the balance between the live and neutral deviates by more than the nominal trip current (usually 30mA). If one is tripping it's because either:
1. Theres a fault in either the wiring or equipment downstream from it.
2. The accumulated leakage currents from the equpiment connectedf are greater than the actual trip threshold of the device (each device tests differently but normally they will trip at considerably less than 30mA). In other words, you've just got too much gear plugged in.
3. The RCD may be faulty/oversensitive or an older type which is not suited to the high levels of DC leakage from modern equipment. This is especially true of lots of RCD extension leads which are really intended for use with lawnmovers and such. Not dozens of amplifiers, LED lights and signal processors.

maltingsaudio

Personally I would recommend only using heavy-gauge 13A-rated 4-gang extensions and keep them solely for gigging . This rules out any problems of wrong extension in wrong place. 

Always use a mains tester befor you set up, and no matter what anyone says, if the mains isn’t correct , don’t plug anything in. Do not just accept it’s right because you’ve been told it is. Also plug it in at the end of any daisy chain you put out just to check all is good.

Finally at least once or twice a year take the top off each plug and tighten the terminals , they do wear loose over time