Masterplug Non-Latching In-Line Safety RCD Protection

Excellent works perfectly

I’m an electrician. The following will not be meaningful to all, but the bottom line for those readers is that the one I received was at least SAFE.Notes:The inline RCD is overly sensitive which might lead to unwanted nuisance tripping in use.It’s a type A according to the spec (not written here – I had to delve about the manufacturers website).Tested with a calibrated Megger MFT:Type A measurement, it trips between 5-10 mA (much too low), in 9 mS. Trip current really ought to be approaching 30mA. I am unable to ascertain a more exact trip time measurement between 5 mA and 10 mA. In other words, applying a DC leakage up to 6mA is INCREASING the sensitivity of the device (better than the opposite way round).Type AC measurement, it trips at 17mA in 20.8 mS. This is OK, slightly sensitive but not spectacularly out, and it's conservatively on the side of safety.My conclusion? – This is an old design to a type AC spec which also “kind-of” passes a type A test (UK standard) when loaded with 6mA DC leakage. Overall, OK.Mechanically, it’s sound. I managed to squeeze in a 1.5mm^2 H07RN-F cable (data suggests H05 cable max which is thinner, the tougher rubber H07RN-F went through the grommet with a very tight seal).I added a little liquid silicone lube to ensure integrity of the main assembly seal (it relies on weathering without a rubber washer).The cable gromets are just a tight fit, not mechanically tightened, but with my very tight H07 cable upwards, it really should work well.Be very careful not to lose the teeny rubber washers which seal the screws holding the assembly plates. They drop out on disassembly, and are a little fiddly to put in place. – In other words assemble this in a clean area where you can retrieve small pieces and put these back on.The cable clamps are of a cage-type, so OK for stranded cable, I added ferrules also for good measure.

I needed to replace the inline RCD that had become damaged on my LazySpa Paris hot tub. This was the perfect replacement as it is of similar size to the LazySpa one and it needs to be placed in an outdoor weather box. It was easy to wire up and the seals around the case and cable input make it very secure. Note that the cable entry points are tight going through the rubber seal - use some washing liquid to ease the cable through.

Works as advertised. Seems good quality. Some reviews say that the input/output sides are not marked. They are, see photo.

I needed a new RCD device for my Lay Z Spa hot tub when a mouse nibbled through the rubber button on the old one - which duly filled with water in the rain (see photo).I bought this Masterplug device as a replacement and it is just the job. The IP rating is IP65 according to the packaging, so it matches the original unit's IP55 rating in terms of water résistance. The casing appears to be a harder plastic so it may be more brittle but time will tell. I don't think that's an issue as it doesn't get knocked about.Fitting is very straightforward. Each end comes off with two screws. You then slide this over the cable, make the terminations, and slide the end back down over the terminal blocks and tighten the screws. The cable has to go through a rubber grommet, which has to be fairly tight to make it waterproof, but a bit of lube on the cable and it goes over fairly easily (I just spit on it, that was all it took). The round cross section of the cable means you get a good seal.The cable terminals clamp down tight on the cable and are arranged such that it isn't fiddly to connect.Note, you must attach it the right way round - the mains plug end on the input and your device (hot tub for me) on the output. These are marked on the casing but aren't obvious, so see my photos.Hope that helps.

Nothing wrong with the product. shame the same can't be said about the instructions that come with it. No where does it say in the instructions that the 'live' feed should come from the top as you look at the device, in fact it doesn't mention the 'live' feed at all. Pure logic would dictate that the 'live' feed should be from the bottom. When I pointed this out to the supplier their answer was that it is on the product itself. IT ISN'T.But hey, it's only an electrical Safety Device, why put it in the instructions.........

I’ve had mine for over a year now and it’s great. Located indoors it feeds my ev charger socket (10A) with no problem.

I purchased these as I often found that the RCDs that plug in at the wall and then have an extension plug directly into them didnt fit many wall sockets, this usually happens with outdoor sockets or sockets with flaps that come down and cover them to stop them being damaged. I use these to run inflatables such as bouncy castles and have never had any problems with it tripping unnecesarily even though the fans have a massive draw on the power. They are well built and are rated for outdoor use although not for submersion. When wiring them I wanted to use 2.5mm rubber cable which was slightly large to fit in the rubber seals so I had to drill the ends out slightly meaning I could get the cable through the seals, there is enough rubber on the seals to allow this and still leave a tight seal on the cable. The wiring is pretty straight forward and there is a cable clamp built in as well then the cover then screws on again forming a seal around the end using a small rubber seal. The RCD seems quite robust although I wouldn't recomend throwing it about as they can be damaged and would then fail to work properly.