If you’re just looking for protection against mains power surges, you don’t have to pay $300 for a ‘high-end’ surge protection board. In fact, you don’t even have to pay a sixth of that! We found three boards under $50 that would protect you from a massive surge of 4000 volts.
However, it’s not always easy to tell from the packaging whether a surge board will give you the protection you want. Seven of the 12 boards we tested performed acceptably in our 1kV and 2kV surge tests, clamping the surge below 900V, and even doing the same in our 4kV massive surge test.
But even though most of the devices we tested survived major surges and would provide adequate protection for connected equipment by clamping at what we deemed an acceptable voltage (under 900V), they still let through more of a jolt than you would expect from their claims.
In fact, only some of the tested devices worked as advertised to protect against surges and clamp excess power at or below the voltage specified on their packaging.
The Crest PRPBS6TC and the APC P5B-AZ were the only two boards tested that passed our 1kV, 2kV and even our extreme 4kV and 6kV tests, while clamping the surge voltage at a level close to that claimed on their packaging, allowing for acceptable variation. Note, however, that the Crest PRPBS6TC specified a lower clamping voltage (775V) than the APC P5B-AZ model (900V). This is one of the problems in selecting a surge board — the specified clamping voltage figures can vary from product to product and were not accurate for most of the products we tested.
In addition, performance claims on the packaging don’t always even use the same terms. The products can use any combination of volts, amps and joules to describe performance (see Jargon buster). Even if these terms are defined on the packaging, it can still be difficult to compare performance claims across brands when shopping.
Our testing proves that you can get decent surge protection at a reasonable price. Our top performer in the 2kV test, the Crest PRPBS6TC, cost only $43 and the top four ranked boards ranged in price between $39 and $65.
If you live in a city, there's generally less chance for a severe spike or surge making it to your home, but for peace of mind any of the top seven boards in our table will do a good job of protecting your equipment from mains power surges. While some are a lot more expensive than others, you may want to select one of them for other features built into the product.
If you live in an outerlying or country area, rather than go for the cheapest board available, recognise that you will generally need to spend a bit more to get a good board to be on the safe side – in the table you can see the units which didn’t handle the 4kV test, and wouldn’t be a good choice for country areas.
In selecting a board be wary of packaging claims of clamping voltage and joule ratings. We found little correlation between the figures on the packaging and our test results. There’s no hard and fast rule, but as a guide aim for a board that has as high a joule rating you can get for the money you’re willing to spend – and, as our tests showed, you don’t need to spend a lot. Theoretically, a higher joule rating should indicate better performance.
Two of the most important features, however, are a status light to show surge protection is active, and a failsafe to prevent the board continuing to work as a simple power board if the surge protection fails. Finally, don’t let connected equipment warranties influence your decision.
The need for rotection
Protecting your gear from spikes, surges and other power fluctuations sounds good in theory, but how necessary and effective are they?
Electricity, including that generated by lightning strikes, follows the path of least resistance. In city areas the power grid, sewage system and other underground infrastructure can provide many paths for a lightning strike to be diverted into, fragmenting and weakening as it’s dissipated. This doesn’t mean surge protection isn’t necessary, but city living can help reduce the impact of lightning strikes.
Outerlying suburbs, regional and country areas are fed electricity via long high-voltage links that provide a more direct path for a lightning strike to follow. If you’re at the end of one of these links, it’s more important to have some form surge protection.
Electricity is a complex subject. Your electronic equipment doesn’t have to end up a blackened, smoking ruin to suffer damage from surges and spikes. It’s a matter of degree. An especially massive surge can short out your system on the spot, but long-term exposure to the more common type of smaller spikes and surges can gradually weaken electronic components and eventually lead to equipment failure. Power fluctuations happen all the time, and most of them happen without us knowing about them.
Manager of the Sydney branch of the independent high-voltage test lab EMC Technologies, Les Dickenson, says modern electronic equipment usually has some form of surge tolerance built in, but the level of tolerance can vary and there’s no easy way of telling exactly how much. That’s because the law in Australia doesn’t specify how much surge protection a piece of home electronic equipment, such as a TV or stereo, has to have, or even that it has any at all.
Not in Australia
Mr Dickenson says the manufacturer’s obligation ends with ensuring the device is electrically safe. That helps protect you from harm, but it does nothing to protect your equipment. He said that in the European Union (EU), for example, there are mandatory requirements for immunity for all products being sold and devices have to be tested to ensure that they comply. But in Australia we have no way of knowing whether a PC, TV or home theatre system we buy has enough inbuilt protection that it doesn’t need an external surge protector.
Surge or drop?
If you sometimes notice momentary dimming of the lights you are likely suffering voltage drops, called brownouts. These can’t be fixed by a surge protector, but might indicate a relatively unstable power supply that could also include spikes and surges.
To deal with brownouts and blackouts you need an Uninterruptible Power Supply (UPS), which provides a battery backup that will cut in immediately if the unit detects a significant power drop. A UPS will give you enough battery time to shut down your equipment safely.
Depending on the type of UPS, it might also regulate the current to your equipment, evening out irregularities to ensure a smooth flow of power. UPS units usually include surge protection on their battery backup sockets and may also have one or more sockets with surge protection only. See our UPS test.
Surge or circuit breaker?
Don’t confuse surge protection with overload protection, or even a safety switch (see Jargon buster), which is designed to protect you from electric shock. A surge board should be clearly labelled as such. Neither overload protection nor safety switch boards provide any surge protection for your equipment.
Plug in safely
The normal safety precautions should always be observed when using any electrical equipment and this applies to surge protected power boards too. It’s especially important to read the safety instructions that come with the device as procedures may vary slightly from one brand and model to another and not complying fully could void your warranty.