[DIY] An audio-dedicated bus bar made simple

Power bus bar for audio equipment

Shockingly simple

What you need:

Trunking: 10€
Copper bars and hardware: 25€
Trip Switch: 10€

Introduction

There is nothing worse than bringing a new bit of equipment into the listening room and to find that you have nowhere to connect it. Unless you have done serious modifications to your home wiring and have a row of plug sockets waiting, this is for you. At the moment I need 12 power points and sometime in the future the need for more will arise. Much has been written about "clean" power and there are those with more money than sense that can afford to buy fancy power conditioners and the like all of which have only a hand full of outlets. This article is not for them.

I do have a separate heavy duty line to my equipment but this is only because I have a 3 phase supply to my listening room and it made sense to have the lights on one phase, the air-con on another which left one free for my equipment. As I always over engineer, the cable to the equipment is good for 100 Amps @ 220 Volts with a 65 Amp breaker at the distribution board. Cable used is Norsk with an aluminum sheath.

Construction

This connects to a bus bar system as per the photo. All of the components for this can be obtained from any electrical dealer as they are used in industry. The first thing to decide is how long you wish to make the bus bars. I chose 1.5 meters so as to have plenty of leeway for future growth. The bus bars are enclosed in a length of plastic trunking about 150mm wide and 1.6 meters long. The trunking should have a clip on top to keep things safe from prying fingers. Three lengths of 6mm square Copper bar are suspended above the base of the trunking on insulated mounting blocks which are also a standard fitting. Keep the bars quite far apart for ease of working with later. A supply of Copper lugs are needed. They have a screw to clamp the wire and themselves to the Copper bar and can be positioned anywhere down the length. Extra clamps can be added very easily as they simply drop on and are tightened down with a screw.

With minimal skills a circuit breaker of choice is installed at one end and also a warning light to tell you when the bars are energized. The piece of copper tubing at the rear is part of the mounting - your trip switch mounting may be different. Connect the incoming power and then the leads from your equipment to the bars and you are nearly ready to go. If you look at the picture you will see the bars are slightly offset to one side to make fiddling with leads to equipment easy. Simply drill a hole in the side of the trunking to feed a cable in and connect up. This system also allows the polarity to be seen at a glance, in my case Line, Neutral and Earth (Top). If wanted a commercial line filter can be fitted between the trip and the start of the bus bars.

Fit end caps and the bus bar system is finished. Make sure you fit the clip on top cover well and if this is going to lie within reach of children use a couple of substantial cable ties around the trunking so as the little fiends can't electrocute themselves.

There is nothing strange about electricity. It follows well established laws and the only iffy thing about it is that it bites when you are stupid. In my country, South Africa, we are required by law to have an earth leakage unit in the main board as you probably do also. This will not stop you killing yourself if you try hard.

[Eskom]

Comments

The picture at right is of my incoming cable from the utility and is a fair representation of how the utility works. If you imagine a bit of expensive cable, which does the last meter or so of a trip measured in hundreds of kilometers, makes any difference at all, then I have some land I would like to sell you. The main journey electricity takes on it's way to you is via Aluminum plated steel wire with horrendous connections.

The wire hanging down on the right of the pole is the cable supplying my property, 380 Volt, 3 phase and 65 Amps per phase. The 5 KVA transformer is a few poles further up the line. The entire area is supplied directly from the utility sub-station via a 50 km high voltage line which are the top three lines. Thankfully most manufacturers have all the necessary filtering for the mains built into their equipment. My TacT amplifier seems impervious to line noise unlike my Triodes which are a bit sensitive. The turntable (EMT), Phono Stage (Jolida), CD player (Jolida) and server also seem to be immune.

A power conditioner may make a difference to your system. I have tried computer style U.P.S. units and if anything they introduce noise into the system. Because our utility is more than a bit unreliable I use a 1,200 Watt for 8 hours, industrial backup UPS. This uses a modified Sine Wave inverter which seems not to induce noise on the line.

To return to the bus bar system - as a method of making multiple connections and keeping track of the Line and Neutral - there is nothing better. Connections take seconds and you are assured at all times of maintaining the correct polarity.

TNT-Audio has been made aware that the arrangement shown in this article does not comply with electrical regulations in the UK, probably other European countries, and possibly elsewhere. The article is offered in the spirit of DIY, but we strongly recommend anybody considering building such a device to check with a qualified electrical contractor or engineer prior to building one. Also be aware that electrical devices that do not comply to regulations will invalidate your home insurance. TNT-Audio takes no responsibility for any damage, injury, or loss of life, resulting from the construction and use of the device described in this article.