fluorescents on a PIR

[r.bartlett]

We have been asked to supply 6 x 6 foot fluorescent battens on a suitable PIR for a coldroom

Should they be 'high frequency' or not and are fluorescents ok on PIRs?

Thanks

Richard

 

[Taylortwocities]

Many PIRs say Tungsten Filament or Tungsten Halogen Lighting only.

6 fluo's coming on at the same time will create quite a high start up current so I would suggest you use a contactor - and a separate circuit for the setup.

 

[flameport]

Should they be 'high frequency' or not and are fluorescents ok on PIRs?

They will need to be HF, as switch start types won't work properly (or at all) in low temperatures. They will also require a suitable IP rating, unless you want them completely rusted away in a few months.
Some PIRs can be used with fluorescent lighting, others cannot, check carefully before buying. The PIR will also need to have a suitable IP rating.

 

[Steve]

I have seen 500 watts of instant-start fluorescents used with a motion sensor before. The ones with contacts are fine. Electronic versions wont work for long.

Is it a small-ish coldroom where the door is left open whilst anyone is in it? If so, fit a door switch. All ours at work have these. We have 5 coldrooms. The ones with sliding doors have a "nudge" switch which has a lever pushed by the closed door to break a contact. The ones with hinged doors have two ELV contacts on the frame, which are joined by a metal plate attached to the top of the door. Making the contacts here turns the lights off.

These switches have the benefit of also controlling the fridge itself, so that the fans arent running while the door is open, for example, as they dont need to be running. They can also isolate the over temp alarm output of the fridge controller while the door is open.

IMO tungsten or LED lighting is more appropriate for coldrooms. By the time a fluorescent has got to a useful brightness (especially in a freezer), the user of the room has usually finished in there. And LEDs will last forever (or until the next time they want their lighting changed)

Would a PIR work in a freezer? Bear in mind the wind chill in a frozen coldroom operating at minus 24, is close to minus 40.

 

[r.bartlett]

It is a coldroom for pharmaceuticals. The room is 10m x 7m so quite large but has 2 sliding doors which will prove troublesome for wiring. The idea of a PIR was to make the fans and lights far easier to wire.

I am going off using flours and will probably just use normal bulkheads with the new halogen replacement bulbs.

As regards the windchill factor it may feel like -40 but it's still -24. (although the 'air off' the coil will be nearer -30 when down to temperature )

 

[mdbalson]

All so put a couple of non maintained em lights in the coldroom as well, as we have had to fit em lights to some of the coldrooms we have installed.

 

[electronicsuk]

All so put a couple of non maintained em lights in the coldroom as well, as we have had to fit em lights to some of the coldrooms we have installed.

Surely this can't be good for battery life unless the EM fittings are specifically designed for use down to such low temperatures? A twin spot fitting with the battery/charger pack outside the cold room would be better.

 

[r.bartlett]

Ah yes we have been requested to provide those too. We have used the twin spot c/w battery pack inside the room before and it seemed ok. The room must not fall below 6 deg c so not too harsh..