condensation on light in freezer

[ice cold]

Hi.

Any of you know why a working fluorescent light fixture in a supermarket walk in freezer would drip?

The drip is coming from one area of fixture and causes a build up of ice on the freezer floor directly under fixture.

The freezer ceiling is dry.

[Brian_UK]

Moisture getting through the light fitting mounting screw holes perhaps or air drawn in through the cable trunking??

[ice cold]

Have you ever seen this type of problem?
Are there many possible causes?
How does condensation occur on the warmest surface (working light fixture) in the freezer?

[Peter_1]

Have you ever seen this type of problem?
Are there many possible causes?
How does condensation occur on the warmest surface (working light fixture) in the freezer?

Yep, saw it many times.
You have an air leak and the pressure in the freezer is lower then the surrounding pressure outside the freezer.
I bet it enter via the cable and melts by the heat.

[Dan]

In the US there are special electrical fittings to permit sealing the conduit with silicone to avoid moisture entrainment into the fixture.

How does condensation occur on the warmest surface (working light fixture) in the freezer?

It might be the warmest part of the freezer, but it is a heck of a lot colder than the air and moisture entering the junction boxes and joints of the conduit.

[Andy T]

Could be the insulation breaking down and is full of ice in the panel which is melting at it's edges and running out through the hole cut out for the conduit for the light.Is it an old freezer room?A good way to tell is look on the roof for puddles of water or lumps of ice.If it not an old freezer still look on the roof to check for wet patches.It could be the fridge pipe lagging and this is freezing and dripping on the roof.I have had all of these.

[ice cold]

It's a fairly new self contained walk in freezer. Roof is good and there are no water lines above freezer. Also, the ceiling is dry, no leaks there, just from the light fixture.

[Dan]

It is the electrical conduit permitting a low pressure vapor path to the coldest point. Seal the conduit and any other associated air-paths from the outside of the freezer to the inside.