32amp Single phase rackmount distro

[userror]

Hi,

Just someone setting up a mobile soundsystem for small pubs/clubs with a few questions about a distro. People IRL can't seem to answer my questions and the pro-sound light forums generally get too much conflicting information.

Penn Elcom 32A Rack Mount PDU With 8 x Neutrik powerCon Sockets PDU16-PC32 PennElcomOnline.com

2U 32 Amp AC Rack Mount PDU With 8 x Neutrik powerCon Sockets, Overload Protection & Power Monitoring 2U high Horizontal Mounting unit designed to provide versatile hook-up for the distribution of AC power within Multimedia Theatre & Tourin .... £427.03.Free P & P.

www.pennelcomonline.com

I am about to build something like above. Except I am not paying £400+ for £100 worth of junk parts.

I have about half the stuff ready, case sockets, ammeters, I have a industrial changeover switch I intend to use so I can select between 16a, off and 32a on the input. I also want to know if Wylex mini RCBO type C are good RCBOs. I know some of the cheaper ones get grief, I also know that spending £50 per RCBO on Schneider might be overkill.

My questions pretty much come down to 6mm 4mm 2.5mm wiring, crimping/soldering for neutrik 20a powercons (and I know the answer is crimping but not sure if I should be using 4mm or 2.5mm wire) and terminal blocks/din placement. I also want to get a circuit tester built into the box but not sure where to get the parts, I'm sure there must be a kit for this now.

I know this is the welcome forum, so hopefully someone could direct me to the best forum diy/commercial for this. Hoping I can just share the project build and absorb any knowledge or advice like a big sponge.

 

[James]

1. a changeover switch for 16 or 32A input is overkill.
simply have a 32A input and different supply cables for 13, 16 and 32A

2. when you say you want a circuit tester built in, what are you wanting to test?

Your problem with a project like this is mainly a paperwork issue.
Because you are not using a type tested or CE marked appliance, you are responsible for the design and testing/certification of the device.
if it was a project for home use, it may not be quite such a big problem however, when using it as part of a commercial enterprise the law is much firmer in that you have a duty to ensure that the equipment is safe.

I would not recommend trying to build this if you intend to use it for public entertainment or hire.

@Rockingit is heavily involved in the entertainment and mobile events field and may have some more helpful advice.

 

[userror]

1. The scenario I am preparing for is the eventual situation where I end up going to a venue that does not have RCBO installed on their 16amp socket as per 2018 regulations. I can't just plug an off the shelf 32amp distro into it, I could end up drawing 32amp from their unprotected 16a socket. In this situation it would be acceptable for the venue to do a risk assessment and know they are protected by my equipment.

I could very well plug the off the shelf 32a unit with a 13a or 16a jumper and if no protection down the line I'm pulling 32amp through 16a or 13a socket even if just briefly.

The changeover switch and additional 16amp RCBO on the input is entirely a safety feature for my own peace of mind, exactly the same with the ammeters etc... My goal is having 1 piece of equipment that comfortably covers 16a and 32a single phase supply...

2. 3 light circuit tester on input. I know I could just plug one into the socket directly or into one of my other sockets but it would be nice to built one into the unit.

The reason I am building this unit is that there are no off the shelf devices which offer the outputs and safety solution I require. I would need the unit I linked too above, and a 16amp version of the unit and it would still not have RCBOs. That's £800 with no RCBOs and low quality components.

The unit spec:
The unit input will be 32a ceeform input with an 100a ammeter.
It would be nice to have a 3 light circuit tester built into the panel.
This will then reach a switch which will allow me to direct current to either 'off' '16a RCBO' or 32a RCBO' into the terminal distro. Then the outputs will be 8x20a powercon outs and 1x16amp socket with it's own ammeter design to supply small stage power or 'gear' belonging to DJ's musicians lighting engineers why.

I am pretty sure this is the route I am going, and I am not disregarding advice to use 'off the shelf' solutions, it wouldn't be dry hired, as a matter of fact I wouldn't let anyone apart from myself handle it. I am actively looking for criticism so whatever I end up with is an overbuilt safe solution. And it's a small project that years later I can build on.

 

[Rockingit]

Thanks @James

So, to the OP, rearrange the question: What is it that you need to power?

From my own (reasonably extensive) experience, your average U.K. pub is good for a double 13A socket and if you’re lucky in a club you might find a 16A socket, very occasionally 32A. However, your kit remains the same. At a guess you’ve got a few bits of backline, maybe a PA with class 4 amplifiers (probably built in) and if a band is really flash maybe a dozen led parcans (or similar). All of which will run on a single 13A (yeah…… they really will) unless there’s something peculiar going on. Also - Powercon/Tru1 outlets may look good, but what’s the point when the bands gear is all on 13A straight out of practicing in a garage? A current meter might look flash but what does it actually help? (Besides…. any band in a pub is looking at a) the MD and b) the next shag, not a dial).

I’ll level with you here - there’s absolutely no difference at this level between a rack mount device like this and a bunch of 4 ways. In fact, a bunch of 4 ways actually benefits you by adding flexibility to distributing the load over whatever power you find available. A decent 4 way will set you back £15 and a 16>13 adaptor about £5. You can donate £100 to cancer research for the advice and still be up on the deal .

Alternatively, if you REALLY want to invest in a rack mount device look at Thomann or Gear4Music instead!

 

[Rockingit]

the t.racks Power 8 IEC VA

19" Power Strip / Power Distributor With current and amp meter, With EMI / RFI noise filter, 106 A total rated current, Filter for reducing interference from high frequency noise and electromagnetic interference >20 dB, 1.0 - 20.0 MHz, Overvoltage...

www.thomann.de

 

[Lucien Nunes]

All things considered I agree that some of the commercial PDU offerings are either too shoddy, too expensive or both. When we designed racks, we used to design our own PDUs too. But that was in quantity, for large contracts. I wouldn't bother making a one-off for myself these days, like @Rockingit I would usually bypass the issue with a K9 and some 4-ways. I've strung a lot of K9s and Toblerones together over the years. Anyway, if you opt for making something, some points in random order:

I don't like original blue / grey 20A powercon NAC3... series for general distro. Not least because they are not designed to be plugged and unplugged live (and if you've seen one flash over, you'll know why.) If you must use a locking compact connector, I would consider the Powercon 16A True1TOP series over the older 20A.

Not sure you mentioned this but obviously the 16A socket and the Powercons need overcurrent protection at 16A when the selected source is 32A.

I tend to ignore 3-lamp supply status indicators built into gear. The important one is 'earth present' but this can very easily give a misleading indication. It only takes a very weak, high-resistance earth connection to make the light glow merrily, but when the chips are down and you have a fault, it turns out that the 'earth connection' was only a bit of backline gear resting against a radiator and the supply earth is not fit for purpose. A stand-alone tester in a plug is a little better in that it won't give a false indication due to parallel earth paths, but if you really want to know whether the supply is safe, there's no substitute for a Zs test with a real tester.

Unless you intend to bunch umpteen circuits together all fully loaded, 2.5mm² tri-rated is fine for 16A / 20A. Did you know you can get Powercons with screw terminals? If you are relying on insulated blue 0.25" push-on connectors at that current, make sure they are good branded ones used with a matching die set in the tool. Cheap push-ons get flaky at 16A.

Because your distro might get connected by a short length of cable to a socket electrically close to the venue installation's origin, allow for relatively high PSCC and PEFC. You'll want to be sure that chunks of burning ammeter don't come flying out of the front panel in the event of a 5kA fault.

Test the feck out of it on completion. Flash test, ducter earth continuity etc. As it's not being made to a BS as an assembly, you need to be sure it offers no lesser degree of safety. Only using it yourself doesn't limit your responsibilities under EAW... it's got to be as safe for you to use as anyone else.

 

[davesparks]

I don't like original blue / grey 20A powercon NAC3... series for general distro. Not least because they are not designed to be plugged and unplugged live (and if you've seen one flash over, you'll know why.) If you must use a locking compact connector, I would consider the Powercon 16A True1TOP series over the older 20A.

I agree on powercon not being good as a general distribution connector, it does make a good latching alternative to an IEC on appliances though.

I'm not too keen on the true1 though, I've seen a fair few failures now. The most common issue I've seen is the softer plastic wearing out and allowing the contacts to go a bit wonky, or allowing the plug to turn too far in the socket and making contact between the wrong parts.

 

[Lucien Nunes]

Is that with the original yellow latch ones or the TOP series with metal latches? I know Neutrik discontinued the original type because of similar problems of them not being robust against incorrect engagement and rotation. We don't give them a particularly hard life in most of our applications, but as a precaution I've been purging the originals and AFAIK we only have the TOPs now.

Before the True1 came out, I wanted a power connector for my video systems that would fit into a standard 24mm panel cutout but specifically avoided using NAC3A blue Powercons not only because of the non-breaking rating and originally the self-unscrewing cover, but because of the very limited protection against shorting to the shell of a BNC panel jack. Basically the back panel of the units I built would have a dozen XLRs, a dozen Ethercons, and a few dozen BNCs. Amongst all those BNCs would be the one mains inlet and I could envisage someone groping down behing the unit in the dark on a cramped stage, and managing to engage a live blue end onto a BNC. It's not as blatant as the figure-8 power lead onto pins 1 & 2 of an XLR3 but it's pretty close. Anyway, the True1 solved this for me and I've used them ever since.

 

[userror]

Appreciate the responses. I will be using this distro to power a crest 8001 and other heavyweight crests and probably have a 10k matrix plugged into it at 8ohms so would only draw 1/2 power when I get around to building some bigger subs in the summer, but that system would need something bigger eventually. I think all the crests all have MCB power switches although only one output on the distro at a time might even approach full load, so I don't need MCBs on 20amp powercons. That said I'm not sure yet. I just want everything here before I start cutting up the box. Would I want a 20amp mcb on each of the powercon outs? It's just occurring to me now I might plug a 10k matrix with a 32amp plug and jumper into it at some point although it wouldn't be connected to a load big enough to use it past half power.

Regarding the ammeters. I have a 20amp on (for the 16 amp passthrough) and a 100amp ammeter for the input. I put one of these (but the DC one on my car after I installed a stereo) I recognised them on the penn elcom distro immediately and figured why not. I want the ammeters because I plan on being able to draw every watt of safe power I can.

I was looking at just running a DIN rail across the centre of the casing inside with a bracket and some 2-6mm 3x12 way terminal blocks. 6mm from the 32amp in... then 4mm to each white powercon socket and the 16amp ceeform. (I will buy neturiks, the updated old style and not the £1 chinese ones). Then buy the little sleeves to cover them. I might spend some more time looking at a good pair of crimps. I don't intent to spend £200-300 on the neutrik crimps. Was just going to use 4.8mm spade terminals with a cheap pair of ratchet crimps.

Again this is why I'm asking this stuff. Eventually I will probably want to do a 63/120a single or a some sort of 3phase. I work in IT mainly so like once every now and then I have to plug a 120a ceeform into the bottom of a rack. I might edit this post and include some of the things I'm looking at buying and let me know if any of it is junk (bad crimps/fastons/blocks).

 

[Lucien Nunes]

Don't forget inrush. What MCB curve do you plan to use and why?

Was just going to use 4.8mm spade terminals with a cheap pair of ratchet crimps.

If I were using grey NAC3...B outlets with 4.8mm terminals, my preference would be to solder. I don't like 4.8's very much at all and certainly not at 20A, most are only 'rated' to 15 with a trailing wind. 6.3mm as used on True1's are better although not perfect.

only one output on the distro at a time might even approach full load, so I don't need MCBs on 20amp powercons.

By this logic, seeing as I never deliberately overload any of my house wiring, I don't need a fuse box. I could connect all the circuits directly to the 100A main switch. Are you proposing to leave them protected at 32A when on a 32A supply?