Electric Power Safety | at Events and on the Stage
Staying safe on stage is more than a matter of simply making sure that willing hands are available to set up gear. Knowing how to properly handle the mains power we all need is also crucial to performance health.
Whatever the size, complexity or cost of your live sound rig, the first question on your mind when you get to a venue will usually be "where do I plug it in?" Depending on the venue, the answer can vary from a wall-socket behind a plant pot to a dedicated and professionally-installed supply that is reserved for your exclusive use, fully tested and certificated, and for which (with any luck) you'll have brought an appropriate connector. Whatever you encounter, you'll need to know some basic rules. When it comes to portable live-sound systems, this means firstly, using a suitable electrical supply; secondly, using suitable equipment; and, thirdly, connecting and using that equipment safely.
This is a deep-dive into information every single person that uses electricity should commit to memory. If you get part way into this blog, and throw up your hands in exasperation, then you would do well to hire an electrician that will watch your back and keep you out of trouble. Even a small amount of electrical power can and does kill. When you are hosting events and performing live music, enormous quantities of electricity must be consumed. Your electrical power must be taken as seriously as any other life or death risk.
How Much Power Will I Need?
What constitutes a suitable supply will depend, of course, on what you need to plug into it: if it's your own equipment you'll presumably know what supply capacity is required, but there may be other factors to consider if additional gear needs to be connected to the same supply. Such gear might include a lighting rig, or a refrigerator at summer events.
A good first step, then, is working out what current your equipment will draw from the mains. The power rating of each piece of gear should be stated on a panel fixed close to where the power cord enters the equipment. The power rating may be expressed as a current (in Amps) or as a power figure in Watts. It's generally best to work out the total current your gear will draw, adding up all the individual figures to find the total load you'll be connecting to the mains. To convert Watts to Amps, divide the Wattage figure by 120 (mains voltage). In a small venue that is only offering 15-Amp sockets of the normal domestic type, you can then work out how you need to wire up. If the total connected load of your system — including the backline equipment — is comfortably within the rating of a single or double 15-Amp socket, it's perfectly alright to connect it all from a single point.
Figuring it Out
One common mistake is assuming that audio output power is the same as the mains power required to operate your gear. If an amplifier were 100 percent efficient, you could, in theory, use all the mains power as audio output power, but this is not the case in practice, as some of the power used by the amplifier is dissipated as heat. A typical full-range 'active' speaker with built-in amp modules, rated at 240 Watts audio output, would have a mains power rating somewhere around 350 Watts.
This table gives a rough guide to the supply current likely to be required by a band using our equipment: http://freshwaterevents.com/electric
Bear in mind that equipment may demand a much bigger supply current when it is first switched on, so don't be tempted to turn everything on from a single socket — you wouldn't want to do this anyway, for many other reasons, such as risking a huge pop through your speakers! Also consider that the power that you can safely run your system on may not be enough to realize its full performance capability. Any system capable of delivering good bass power will need to draw a hefty current from the mains, and if, in the above example, we were to replace our typical small speakers with, say, a pair of subwoofers, your power consumption will increase exponentially. This illustrates how important a good power source is for getting the best from your gear.
Hint: You may also wish to purchase a power strip with a PDU (Power Display Unit) that will inform you of exactly how much electrical current you are consuming.
While we're talking in Amperes, it's worth remembering that electrical current is highly dangerous; a current of only 50 Milliamps (0.005 Amps) can be fatal, and our typical small rig above is using more than a thousand times more current than this. Safety is thus a huge consideration, and the use of a suitably rated supply is only the beginning. The best way to stay safe is to use only well-maintained equipment (including cables and connectors) that are properly designed for the task in hand, and to make sure that they are used as the manufacturers intended.
If the venue in question is unfamiliar to you and you are responsible for providing and operating the PA, always check that the supply you're asked to use is suitable. Just because it's a 20-Amp socket doesn't mean that it's capable of supplying 20-Amps: it may have been DIY-installed as a spur from a domestic ring main, originally to light a garden shed or run a fountain or something! If you're operating in any kind of business or commercial premises, they should have an up-to-date electrical safety certificate. A quick look at the distribution board or consumer unit should show the overall current rating of the circuit you'll be using, and you can also see if it uses old-style wired fuses or the more modern MCBs (Miniature Circuit Breakers), which react more quickly if the rated current is exceeded.
Fuses and Circuit Breakers do not protect you from electric shock, so always make sure that your system is fed via a ground fault circuit interrupter (GFCI). This could be at the main board/box, on the socket itself, or at the point where a separate spur is fed. If you're not sure that this is the case, use your own GFCI, either as a plug type or one of the GFCI plug-in adaptors readily available for a few dollars from any electrical retailer. The GFCI should be as far 'upstream' as possible so that it protects as much as possible, and wherever it is, make sure you test it before use, by using the built-in test button. If it doesn't seem to work, find another! A final word on GFCIs: they are there as a backup in case anything goes wrong, not as a substitute for poorly-maintained, faulty or unsuitable equipment.
Having found a suitable supply point, you now have to feed it to all your equipment. For all gigs where a 'proper' supply is available, we use a professionally made portable distribution box, which has a single 50-Amp 240-volt inlet, feeding multiple 15 and 20-Amp 120-volt outlets, all via their own separate circuit breakers. I run my front-of-house speakers from two of these feeds, the monitors and mixer from the third, and the stage backline from the fourth. This splits up the load and ensures that each feed is fully protected. As mentioned earlier, it is always best to have an GFCI as far upstream as possible, and I would ensure that my original 50-Amp source incorporated suitable protection if available.
Care and Maintenance
All leads, connectors and equipment should always be checked before use, even if this is a quick visual check for any obvious signs of damage. If it's your own gear, you'll know it's all correctly fused, but it's best to check if you're not sure. Cables should be undamaged along their entire length and plugs should be securely clamped on, with no inner conductors visible. Cables with molded plugs are a common sight nowadays, but these plugs cannot ever be re-used if damaged. If anything looks faulty, then it probably is. Remove it from service and make sure it can't be used again until it has been repaired and tested. All electrical equipment, including cables and connectors should be stored and used in dry conditions unless it is designed for outdoor wet weather use and carries an appropriate IP rating (for mains connectors this will usually mean industrial; either rated IP44 (which is splash-proof) or IP67 (which is waterproof).
Electricity is one of the most useful (and used) modern inventions in the world. It’s the bedrock on which almost everything runs in your home and business; and increasingly in other ways, including electric cars. Given the importance of electricity, it’s essential for all of us to have a reliable, uninterrupted supply. While each utility company strives to provide this, sometimes a power surge can disrupt the process. Join us as we uncover everything you need to know about what power surges are, why they occur, and how to prevent one from happening in your home.
Power surges are just as the name suggests: surges of electrical power that are higher than normal. Typical voltage levels for household appliances and electronics are between 110 volts and 220 volts in most countries, with the United States operating on 120 volts on average. When significantly more voltage comes through wires into devices, it’s known as a power surge. These surges can be small or large, resulting in reduced performance or possibly damaging your plugged-in devices.
How Do Power Surges Happen?
Power surges happen in three main ways: when there’s an interruption in the flow of electricity followed by a short; when an increased delivery of power is interrupted when electricity is sent flowing back into the system; or when a sudden increase of voltage is sent through a power system from internal or external forces. Power surges can range from as little as one volt over the threshold maximum to thousands of excess volts, such as when lightning strikes power lines or a transformer.
There are several causes for a power surge. The main reasons are electrical overload, faulty wiring, lightning strikes, and the restoration of power after a power outage or blackout.
Electrical overloads can occur when too much power is drawn from a single circuit. This happens most commonly from overusing extension cords and plugging in too many devices into the same circuit. Power surges are common following electrical overloads as the overwhelmed single circuit can receive a massive current and subsequent voltage spike from the excess power being drawn.
Faulty wiring is a potential internal cause of power surges, which are more likely to happen with damaged or exposed electrical wires. It may not be easy to see faulty wiring, especially if it’s located behind walls. However, there are other signs that faulty wiring is present. These signs include outlets with burn marks, a burning smell coming from wiring or outlets, a buzzing sound coming from outlets, and circuit breakers frequently tripping. If you see these signs, unplug any connected electrical devices immediately and turn off electricity to the area if possible. It’s best to contact a certified electrician if you suspect faulty wiring.
How Can Power Surges Be Prevented?
There are several ways to prevent internal power surges, and several ways to prevent damage from external power surges that are out of your control. Internal surges can be prevented by making sure your devices are not overloading circuits. Large appliances such as air conditioners or commercial refrigeration units shouldn’t share the same socket with other appliances, and you should make sure your wiring is up to code. While external power surges are sometimes unavoidable, you can still prevent them from causing damage by unplugging your devices and appliances during severe storms. You can also utilize surge protectors for your appliances and gadgets, which block excess voltage from reaching your electronics in the event of a power surge.
How Can You Prevent a Power Surge From Damaging Your Electronic Devices?
Aside from unplugging your devices when not in use, there are a few things you can do to safeguard against power surges. Using point-of-use surge protection devices, especially when combined with a reliable grounding system, will protect electrical devices from all but the most severe power surges. Plus, you can also use special wall outlets that offer additional surge protection. You can easily find these items at most local hardware stores or home improvement centers.
Are Power Surges Damaging to Your Electronics?
The spike in voltage that causes power surges has the potential to damage electrical devices and appliances. When voltage increases above normal capacity, it can cause an arc of electrical current, with associated heat also posing a risk to electronic components. Even smaller power surges can cause damage if they happen frequently. This could be the reason that your devices and electrical appliances stop working for no apparent reason.
Do not quickly blame the power grid due to its archaic structure. Remember that the wiring within most buildings is also out of date. As a result, these wires are straining to supply a wide array of appliances, electronics, and lighting fixtures that require electricity.
Let's take a look at the common causes of electrical concerns and how to fix them.
Often, when you use a device with a higher wattage than the fixture, it can result in a common electric issue—overloading.
Heat generated by this device can melt the socket and the insulation in the fixture wires. Sparks can form from one wire to another, resulting in an electrical fire. Even if you remove the device, the wires have already sustained damage. Make sure that your devices operate within the ideal wattage for the fixture and circuit.
We've all performed in these venues with questionable power. Be careful out there. The damage may already have been done by the band that performed before you. Pay attention. If it smells hot, do not hesitate to unplug your equipment.
An electric surge can occur due to poor wiring in the building, faulty appliances, downed power lines, or lightning strikes. Surges are common and typically last for a short while, but these can destroy your electronics and appliances, shortening their lifespan, most especially if the surges occur frequently.
Ensure that you inspect the device that connects to the grid or the wiring. If the electrical surges continue, it is best to get in touch with a professional electrician from a reputable firm.
Power sags and dips
Just like with electrical surges, the sags and dips in the electricity are likely due to the devices connecting to your power grid, and which are faulty or made with mediocre-quality materials. Remember that these devices take up a lot of power if you switch them on. Sags and dips can also occur if you have several large appliances running simultaneously, especially when using up significant power from an out-of-date electrical panel. In most cases, such an occurrence only lasts for a moment without turning off completely.
Uncovered junction box
The junction box contains several wires that are connected and installed during construction. Once it is bare or left open, a person is at risk of getting a shock from a damaged wire. The box should have a cover. If it is open, it poses a safety hazard. The junction box’s main purpose is to protect anyone against electrical shocks and prevent a fire from spreading that typically starts on damaged wires. Make sure to cover it with the panel cover and screws provided by the manufacturer.
Frequent tripping of the circuit breaker
High wattage appliances and electronics, such as hair dryers and microwaves, can easily trip the circuit breakers, especially when other high-consuming items are used simultaneously through the same source. Take note that a circuit breaker works to protect your house; once it trips, it is an indication that it is doing its job. You should check what you were using when it tripped. Additionally, limit the electrical consumption on a single circuit while you are using high-watt devices.
Today, the majority of buildings utilize extension cords and power strips. In case you do not use heavy load extension cords, such as 12-gauge or thicker, the risk for problems will be minimal. Remember that the thicker the wire, the lower the gauge number. The smaller or 16-gauge extension cords are likely to overheat and start a fire if the loads are too heavy. The ideal solution is to install more circuits.
If a panel contains several circuits, you have an over-wired panel. The tandem breakers serve as a replacement for several of the single-pole breakers in one slot. Take note that a label on every panel indicates the level of circuits the panel can accommodate. The solution is adding a subpanel or replacing the current one with a bigger model.
In the 1960s and 1970s, aluminum was an affordable alternative for copper, but it is no longer a safe option today. Aluminum corrodes once in contact with copper, resulting in slack connections, leading to arcing and fires. The remedy is to add an aluminum wire to copper connection to a dielectric wire nut for light fixtures. The nuts have a special grease that stops corrosion, while ensuring proper conductivity. Always check that any new switches and receptacles are AL-compatible.
Plug falling out of the receptacle
When a plug falls out of a receptacle, it simply means the worn contacts in a receptacle do not securely grip the prongs. There is a high danger level since loose contacts can result in arcing, igniting dry wood and dust. You should take out the old receptacles right away and replace them with new ones.
If you are not using electricity properly, it will put you at risk of an electric shock, which can be an undesirable and often fatal experience. The risk of this electrical issue in old buildings is high due to the circuits fitted during the past. The issue might stem from the appliance or even the wiring. The best approach is to consult an electrician for a proper assessment of the issue.
If you have ungrounded receptacles, the wiring in your building, event tent, or stage does not have a safe way to control any loose current that runs off the wiring. Do not utilize an adapter to load a three-prong plug into a receptacle that has two prongs. If you do this, it will damage the device you are plugging in and increase electrocution risk.
The remedy to this electrical problem is to swap out two-prong receptacles with well-grounded three-prong receptacles, if possible. Do not forget to test all current three-prong receptacles using a GFCI circuit tester to see that they are grounded.
When you are facing any of these electrical problems, try to be careful at all times since they pose a dangerous hazard. Depending on the type of electrical issue it is best to get in touch with a licensed Master Electrician to deal with the problem correctly.