Electric gates and automated doors work great until something in the electrics goes wrong. Then the units become a liability for the business. Water gets into connections, cables become damaged, and all of a sudden, you’ve got an outdoor installation with mains voltage running through it while people walk by all day.
Safety reulations and accross the board standard safety practices are in place due to previous accidents that have happened. An untended piece of maintence on a control board, a gate becomes posotioned down on a person and traps them because the safety features are programmed wrong, a motor has a thermal runaway due to the wiring being out of standard and a fire is present. Addressing and executing safety modifications to these machines is crucial to safety.
RCD Protection Requirements
RCDs are the breaker switches in your consumer unit that go off when they detect a fault. They monitor the current flowing through a circuit and if some of it is leaking where it shouldn’t, the RCD shuts off power to the circuit to avoid the danger of being electrocuted.
All automated doors and gates require RCD protection. It is not a negotiable requirement because of the current wiring regulations. These installations are subjected to the weather, they are installed in garages that are prone to flooding, and they are in locations where people can access them easily. The opportunity for something going wrong is too great not to have that protection.
Most installations will use 30mA RCDs which trip if current leakage hits 30 milliamps. While this does sound like nothing, it is enough to kill someone if they are unlucky. Some installers, especially for commercial work where liability is a greater factor, use 10mA RCDs for further protection.
With RCDs, the problems will usually stem from nuisance tripping. Small moisture build ups in outdoor junction boxes, condensation in the motor housing, and other small areas, can cause minor current leaks that are not dangerous. However, while they are still not dangerous, the control will trip regardless as a protection measure. This can leave you stuck.
The temptation to bypass the RCD, or to just swap it with a less sensitive one, can be great. However, avoid this at all costs. If it is tripping repeatedly, it is doing this for a reason. You need to find the fault and fix it.
The RCD is supposed to be tested monthly by pressing the button, however does anybody actually do this with a domestic installation? Probably not. However, with commercial installations, this needs to be documented and if there is an accident, problems also arise with the HSE and your insurer if you cannot show when the RCD was last tested.
IP Ratings for Outdoor Equipment
IP ratings measure the amount of protection an individual item or unit offers from the weather. The first digit of the rating covers protection from dust and the like, the second digit deals with water. An IP65 rating means that the control box is dust-tight and can withstand water being sprayed from any direction. An IP54 rating offers slightly less protection and is acceptable for kits that are under moderate cover.
For gate motors that are weather exposed, an IP65 rating is the absolute minimum, and control boxes are the same unless there is sheltered mounting. Junction boxes that are buried into gate posts certainly require proper ratings because water can easily get in and evaporating is not really an option.
These ratings mean little though if installation is not done properly. Drill holes into an IP65 rated box and leave them unsealed? Not IP65 anymore. Use cable glands that are low quality and don’t tighten fully so water can easily get in? Fit the box the wrong way around so the water can easily pool? That is asking for detail trouble.
Cheaper pieces of equipment are usually the culprits of this as they often advertise IP ratings they do not really have. The lid may sit on a poorly constructed seal that’s already cracking, or their cable entries do not have glands to seal them properly. You get what you pay for.
Box corrosion can happen even with good sealing. During the colder overnight temperatures, the moisture in the air traps and condenses inside. Plus, the corrosion inside the compartments starts on the terminals. Breather control vent boxes have the function to circulate the air, but this control is often blocked by dirt, and over time, also by insects.
Appropriate Installation Distances and Clearances
Automated gates and doors can create squeeze points. There’s no way to completely block this problem, but the guidelines define the clearances to minimize the problem as much as possible.
For the crushing zone, meaning the area where the gate closes, you need at least a 500mm clearance from any fixed object. This leaves enough zone if someone were to be caught to be able to get out and to safety from the gate, for example, if a brick wall or fence post is in the way. The requirements might be larger for some scenarios, depending on the weight and speed of the gate.
Swing gates are especially problematic as they sweep through an entire arc when opening. If a person is in front of a heavy gate when it starts to swing, they could get pushed over or lose balance. Warning signs can help, but the design is more imporant. Beacons and flashers, though not required for residential uses, activate to warn that the gate is about to move.
Roller shutters and sectional doors require headroom. The ascending edge needs to clear head height by around 2.2 meters and above. It needs to be accounted that deliveries are likely to have stacked boxes that might block the opening.
Safety edges installed on the gates that close are designed to sense and reverse the gate. These do work and are necessary, but only when not damaged. Make it a point to test them on purpose. If a gate fails to stop or reverse when a safety edge is pressed, it shouldn’t be used until it’s fixed.
Photocells that reverse gates are also designed to break the beam and require deliberate placement. If set too low, twigs, leaves, or random bits of wrappings will block them and set the beam. If set too high, they will miss a small child or a dog. The point is usually around knee height, but is often adjusted to work better.
Not that you’d believe it, but spider webs over photocells are common. If the beam getting blocked is the only reason the gate won’t close, don’t let a web stop someone from closing it.
PAT Testing for Commercial Installations
PAT testing involves confusion for many people because the gate motor itself doesn’t need testing while the intercoms, control panels with plug tops, and other moveable appliances do need testing because they/dust plugged into sockets of the commercial setting.
How often testing takes place will depend on the risk assessment. If there is equipment OUTDOOR, in rough, harsh conditions, they probably need annual checks. If it is sheltered equipment and doesn’t get much wear, they could stretch to two years. Some industries are fussier than others, and your insurer might have requirements.
The test itself checks for obvious damage, correct wiring, earth continuity, and insulation resistance. It takes a few minutes per unit of equipment for you to get a pass/fail label stuck on equipment along with the date and retest date.
For gate systems, a proper inspection, rather than just PAT testing the plug-in bits, by a knowledgeable person is more reasonable, They assess the safety features, check the fixed wiring, the motor operation is tested, and they look for mechanical wear. Rather than just knowing there is good earth continuity on the intercom, you get the full picture. It is a more informative result.
Businesses need to have documentation. If something goes wrong and an injury occurs, the first question is whether the equipment and pieces of machinery were maintained and looked over regularly. If there are no records, you are in a bad place, even if the pieces of equipment were fine. Courts and insurers won’t believe a company if they say they looked at the equipment without any documentation.
Some companies become relaxed and complacent when a system runs for a few years without any issues. Everything is running smoothly, so what is the point of spending money on an inspection? Then someone gets injured and the HSE investigates; and all of a sudden, the annual inspection that costs about £200 looks really cheap in comparison to the fine and legal expenses.