Indoor PIR master & slave set-ups: are they worthwhile? Timeguard’s Andy Douglas gives his verdict.
Manufacturers will offer you master and slave versions of their products and it can make sound financial sense to use them, especially when the list price of a master PIR detector is likely to be double that of its slave.
A master/slave set-up also saves you the time (and some would say hassle) of setting up Lux trigger levels and ‘on’ times for each unit. Used correctly, these set-ups help you to create better control of its environment – anything from having lights switch on before people enter an office to switching internal lights on for the whole length of a corridor.
The usual warnings about quality and ratings apply, whether for single PIRs or master/slaves. So rather than use bargain basement PIRs, you’d be well advised to trust quality branded PIRs for controlling your lighting.
The outcome of this is that the savings made from using master/slaves enable you to ‘trade up’ and always use higher-quality, branded goods – a double ‘win’! Following on, master and slave set-ups will still deliver big savings for your customers with enhanced energy saving.
Ratings and reputation
It sounds obvious but there is a limit to what each master can do, so make sure you check the ratings. Turning on a string of LED luminaires, year after year, is a big ask of any switch, so you need to be confident that the rating can manage it.
We’ve been warning about LED switching for many years now, because a switch must cope not just with the headline load but also the transient spike that is characteristic of LED lighting. Make sure that you look for a specific LED rating – you’d be surprised how many products still fail to make this crystal clear on their packaging.
Time is money too
Realistically, the over-riding reason for using master/slave set-ups is usually going to be a financial one. But your time is a big issue too, so you must factor in the whole job, not just the bill at the wholesalers. If you’re saving, say, 50% on a second detector by choosing a slave, remember that it still has to be fitted, so look out for easy-install and plug and play options to consolidate the savings.
The great outdoors
With LED now popularly used for most floodlighting, 30W and 50W luminaires are not uncommon. Clearly you would want to think twice before you rely on one PIR switch to manage more than a pair of 50W floods.
We rate Timeguard’s latest PIR detectors for the LED Pro floodlights to switch up to 140W LED. Of course, 140W will control a whole string of 10W, 20W or 30W floodlights quite happily: just make sure the total doesn’t exceed the rating.