My local wholesaler was having great problems with electricians returning LED floodlights with attached PIR sensors a couple of years ago. The issue was that the PIR had a lower IP rating than the actual flood light, it came to a head when an electrician returned around forty fittings installed in an area where pressure washers were used frequently.

Most of the electricians went back to using stand-alone PIRs and the wholesalers cleared their stock with customers being advised about the IP rating issues and restocked with better fittings.

Other than for a single light fitting I still use stand-alone PIRs rather than integral PIRs, the four-core wiring in the installation is better as other controls can be added such as time lag switches and timers.

I have done some external lighting with a combination of stand-alone PIRs, switches and a timer connected through a photocell, so the lights come on as it gets dark, go off at 11.00 pm, but come back on if someone enters the garden between 11.0 pm and dawn or if the occupants want to manually override the controls.

I too prefer separate PIRs - simply because generally PIRs have to be mounted relatively low and pointing roughly horizontal for best performance (as high up they see only the tops of people's heads and so can be defeated by hats and winter clothing) - whereas floodlights (whether LED or otherwise) are generally better mounted high and pointing down to avoid dazzle and give a decent even spread of light.

I guess one way of persuading manufacturers to stop producing rubbish designs is not to buy them - although the all-in-one-easy-to-wire-as-a-13A-plug option will likely continue to appeal to the DIY market regardless of the technical merits otherwise.

   - Andy.

I concur with the last two comments. It is often a good idea to have the ability to link PIR floods to a one detect then several illuminate situation - not no all switching outputs allow this anyway unless you put your own relay in them. You have also to be aware of total load allowance too.

Also the old original PIR flood combos were british made (apparently) and had a large-ish linking arm so that swivel of detector and flood could vary a bit between each other. However, back then say early 80s they were about £45 + VAT each and put that in todays money and they were quite a few bob each. If my memory serves me correctly.

Today we live in a more sort of "Cheap as Chips" society but avoidance of cost and over-engineering (that we used to get accused of) brings it all to a race to the bottom. Great prices but often leaving something to be desired.

This was still in the days that washing machines etc could last 20,30,40 years and over and if you go a computer or something you`d keep it for at least 10years.

Ultimately I usually go for separates even though just the PIR switch alone often costs more than the whole combined unit.

One thing I`ve done a few times whether combined or separates if using two or more is to link via a simple lighting plateswitch . Link the commons as a common bus and the separate units to the One way switch terminals. Therefore a 2,3,4 or 6 bank of lighting can allow each one to be tested/set up individually but switch over allows a group setting. Of course this basic idea can be overtaken by readily available GSM/WiFi tech these days.

I haven`t even mentioned such as GJD Opals etc either.