WHAT ARE YOU PLUGGING IN TO?

Hardly any machinery or entertainment system and least of all navigation system now runs without sensitive electronic processing equipment. Aside from your IT equipment, everything now seems to have a computer or some sort of processor inside. And with the “Internet of Things” pushing its way into every aspect of connectivity and monitoring, be it for convenience, AI (Artificial Intelligence) or Big Data, every system has simply become more sensitive to power fluctuations.

A slight dip in voltage (Brownout), or a start-up spike can cause havoc in many electronic pieces, a sudden loss of power causes failure in storage and memory, and corrupts programming. Dirty or “noisy” electrical sources do not normally cause harm to the system but can be heard in audio circuits, causing hum or popping sounds disrupting the acoustic experience.

Considering that electricity on a vessel is inherently constantly changing, either generated from onboard generators, created by inverters or at times being switched to Shore power, brownouts and blackouts are not uncommon. This combined by earth leakages through wrongly grounded equipment or cathodic current running through the ships hull due to neighbouring vessels or from the harbour itself is simply detrimental to all onboard electronics.

Two different types of equipment are available to protect against this, the UPS and Power conditioners. Understanding the difference is very important, as important as understanding the need of properly grounding all electronic units to the vessels earth plane.

UPS (Uninterruptable Power Supplies) come in various flavours, and as often the case, the more expensive, the better the performance. They provide backup electrical power for a short period of time to critical equipment in the event of brownouts or during a total failure of normal electrical service. The lower cost versions tend to be ‘line-interactive’. This is when the mains enters the UPS and stays as AC voltage passing directly out to the load. The battery only comes online when the power is lost/voltage falls out of range. This still causes a few milliseconds long switch-over, and more importantly a disruption to the AC sinewave, which can be harmful to some electronics.

An ‘online’ UPS uses an inverter that is always powered via the mains. The battery source will only actually kick in if the voltage is out of tolerance or completely missing. The mains enters via a rectifier, converts to DC, and then through the inverter back to AC and out to load. This is also known as ‘double conversion’, which means that the output is voltage and frequency independent from the input…. giving a constant sinewave output. Battery comes on instantly, no switchover time.

Also, careful here, lower cost ‘online’ UPS’ produce a square-wave on the output, although most electronic equipment can deal with this, for more delicate and high-performance equipment it still potentially problematic!

The first type of UPS’ (line-interactive) do not filter the AC going through it in anyway, it simply kicks in when it sees the incoming voltage dropping away. Transients, Surges, Spikes, Common Mode Noise, Line Frequency, High Frequency Noise still transit the UPS’ and can cause issues mostly on audio units.

A comment on “Surge protection”, often sold as part of a low-cost power strip. Here the industry takes advantage of consumers, selling devices at a premium price, when these units actually do very limited work. It is very important that you ensure you are aware of what you are really buying.

Power conditioners are devices that provide protection against surges and spikes in power, as well as basic electro-magnetic interference (EMI) and radio frequency interference (RFI) filtering by use of suppression circuits that keep this interference out of power supplies and their associated audio circuits. Spikes and surges are already highlighted for potentially causing serious damage to your equipment. Whilst EMI and RFI don’t usually damage your equipment, they cause unpredictable and unacceptable noises in audio equipment.

However, do note that most off-the-shelf power conditioners do not stabilize line voltage, which can be an important element in protecting your electronics. A voltage regulator attempts to keep the line voltage that goes out to your equipment stable at 120V or 240V within a specified narrow range (assuming the source voltage stays within the range of what the regulator can regulate). Low voltage or overvoltage can seriously affect the performance of electronic equipment and frequent instances of voltage fluctuation can permanently damage gear. A voltage regulator may be your first, best choice for protection as these usually have all of the power conditioning components mentioned above as well. Voltage regulation is especially critical if you use a lot of vintage gear, which can sometimes be more sensitive to fluctuations.

The bottom line here in order of importance to protect your expensive electronics is to ensure that everything is always properly grounded. Ensure it all has protection against brownout, blackouts, surges and spikes.  And ultimately to give it extra life and ensure you remove hum, buzzing and popping noises through the use of power conditioning.

This article was written by Tim Gorter, teletechnics.com. Tim focuses on troubleshooting of Audio/Video installation, network monitoring services and RF / WIFI network surveying to ensure that you get 100% connectivity, where you want it! (That be everywhere, right?!?).

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