Fermentation chamber build (Philips AMB 415) - not sure where to drill

So I’m trying to setup my freezer and I noticed there is not a single hole going inside, which means I’ll probably have to drill a hole.

However, I’m not much into the freezer technology and thus not quite sure where it will be safe to drill it.

Where would it be safe to make a hole for the wiring? Hope the images are helpful.

Other question I ran into is: do I need to override anything in the freezer? I was thinking into going something as simple as using the SSR for turning on/off the freezer power, since it doesn’t even provide a lamp inside.

Does the freezer have a fan and a condenser in the roof? Then the cooling happens inside the fridge and not in the walls, which means they are probably safe to drill.

Power it on and feel: does the back get cold? do the sides get cold? Try to see how your coolant lines run.
A good location for sensor connections would be in the bump. I think it is also unlikely that there are coolant lines there.

However, you probably want to make a platform above the bump.

If you drill through the sides, first only drill through the upper metal layer. Then poke around in the insulation material to feel if you are clear.

Thanks again for such a quick answer.

It doesn’t contain anything on the inner roof. On the outer, just what is seen in the picture and after further investigation, nothing going inside from there either.
The bump also run though my mind as a nice spot already, so I’ll probably use that one. I’ll first double check your advise and try to find the coolant lines by turning it on.

As a platform I’ll use one of the shelves, which don’t show up on the picture since I took them out for cleaning. There’s one just right above the bump.

Regarding the SSR, since I don’t want to override the freezer nor the heater cables, I’ll make two extra cables from some spares I had here.

In this picture is one of them: