light fittings in a fridge

[ians]

When carrying out an inspection report for cold rooms, how many people check the type of fitting used?

I have just been called out to check a light in a cold room and found that all the lights are standard 4 ft weatherproof fittings (the cold room is at -15) This job was done as a new installation a year ago, which means the COC is invalid, if there was one issued but i suppose the light fittings are not covered by the COC.

[AndyD]

I think the only difference between a standard fluorescent light fitting and a low temperature one is the type of tubes. Standard tubes will work at -15 they're just at reduced in light output and may be prone to slow starting, flickering and shortened lifespan. I would say the weatherproof fittings are fine if they're SABS approved because the cover would protect the local area in the case of a broken tube and none of this would effect the issuing or validity of a COC.

[Dave A]

I would say the weatherproof fittings are fine if they're SABS approved because the cover would protect the local area in the case of a broken tube and none of this would effect the issuing or validity of a COC.

Not an electrical COC issue, but from a food safety point of view the bulb/tube glass really should be in a containment sleeve so that if the glass breaks there is absolutely no chance of glass contaminating foodstuffs. I don't think the light cover would resolve this adequately, as how do you remove the light cover and still ensure absolutely no glass, not even the tiniest sliver escapes into the food area.

[AndyD]

I assumed Ian meant one of these



which would resolve the issue of glass contaminating food during the actual breakage. As for removing the cover after a breakage it would be down to preparation, removing foodstuffs within a decent radius, use a sheet to help contain any spilt glass and a thorough clean-up afterward. Even containment sleeves don't guarantee against spillage during removal, only during the actual breakage event.

[mikilianis]

Interesting

[ians]

You can use a weatherproof/dust proof fitting, but not one with an electronic ballast, as some of the ballasts are only rated to -10.

You can use a WP/DP fitting with starters, so long as you use the starter designed for the application.

The freezer room i am working in goes down to -18, so cool when it is 32 outside. But when you spend tooo much time inside it feels like your brain is going to freeze and you start getting a headache. I found a quick way to check the drains are not frozen for the units inside the room, thermal imager saves having to climb a ladder to check.

[AndyD]

You can use a weatherproof/dust proof fitting, but not one with an electronic ballast, as some of the ballasts are only rated to -10.

Even at -18 in the room the temperature will be several degrees higher inside the fitting with the heat coming from the tubes and ballasts and almost zero airflow within the fitting. To be honest I wouldn't consider the temperature rating of the fittings/tubes to be a problem worth any attention unless they were failing regularly or giving problems with flickering or flashing.

[Justloadit]

Even at -18 in the room the temperature will be several degrees higher inside the fitting with the heat coming from the tubes and ballasts and almost zero airflow within the fitting. To be honest I wouldn't consider the temperature rating of the fittings/tubes to be a problem worth any attention unless they were failing regularly or giving problems with flickering or flashing.

Hi Andy,
True when the lights are on, but what happens if the lights are switched off for a period of 24 or even 48 hours? The temperature inside will eventually match the temperature outside, and the electronics may not function properly. One way to get around this, is to place a very small heater in the electronics control unit, to maintain the temperature above the minimum low temperature of the electronics, but then again this would require a separate supply wire specifically for the heater when the lights are turned off.

[AndyD]

You're right, if the light was switched off it would match the temperature of the coldroom or freezer room in minutes probably. It's just an issue I've never come across, we've installed fluorescent lighting in coldchain premises and coldstorage on several occasions over the years and it's always worked well. It does run a little dim for the first minute or so but we've never had complaints or premature failures as yet.

Does anyone have first hand experience of how LED systems perform at -18 to -25 Celsius? I'd be interested to know for future reference.

[ians]

The lights are in a cold room, swtiched on for 5 minutes,off for hours, on for 5 minutes.

Got a callout this morning to the shop, all the screws securing the circuit breakers trays look like they have shorted out, we found the neutral conductor from the transfomer to the meter room was stolen last night, so now there is 160 volts neutral to earth, had to shut the entire complex down. These thieves who steal these cables should be charges with more serious charges as this becomes dangerous for staff who are working on the steel equipment. Lucky no-one was electricuted , but the consequenses of a person stealling the neutral bussbar and not switching off the power creates a dangerous working enviroment.

[Rock Wood]

To protect from damage, I use compact fluorescent bulbs in my refrigerator.