If it's of any help, UK regs generally require accessible top surfaces of enclosures (including DBs) to be IP4X (or IPXXD), primarily to keep dust out (416.2.2 of BS 7671) - I wonder if it's a mis-interpretation of a similar requirement. If the manufacturer doesn't specify different IP levels for the different surfaces then you might well have to go for something labelled IP4X.

  - Andy.

Point of order AJ, IPXXD would definitely not keep dust out as the aperture can be up to 32mm in diameter. 

I do not think that you will find much expertise in Danish law here. However, whenever somebody says something like, "By law it must be IP44 in Denmark.", I usually ask them to give me the reference to the law.

In some ways, we do that all the time in here.

Fair point. The IPXX* ratings do seem to have their flaws. I guess in most cases where the hole in the outer casing is that large there'll be some internal barrier to prevent a direct line to live parts, so hopefully not too much of the dust will reach live parts.

   - Andy.

Google found this for me: https://www.sik.dk/en/business/legislation/electrical-safety/executive-order-electrical-installations

it seems surprisingly detailed for legislation (compared to what we have here) (use the "+" buttons to expand out each section). It seems to suggest that compliance with HD 60364 is sufficient though.

   - Andy.

Thank you so much for your support AJJewsbury , Chris Pearson  and lyledunn  for your support. 

After doing a through research I found in Denmark,  it is necessary to have IP44 rating for all equipments in horticulture applications. 

Again, Thank you for your support.

Ah, if the "corridor" is considered to be part of the agricultural/horticultural installation (i.e. on horticultural/agricultural premises and not exempted as being a location whose environment is similar to offices, shops or residential locations), then BS 7671 has a similar requirement - 705.512.2. Not sure if that aligns with HD 60364  though.

   - Andy.

Hi Andy, Thank you for the reply. 

It's actually not mentioned anywhere in danish code either (Means not clearly defined either the whole building falls into this category or only the growing are).

The corridor is not in the grpwing area yet there are is mist and humidity in the room due to poor weather proofing of the building. If not for that, I could have easily consider this as a normal area (withthe benifit of the doubt of grey area in danish code) 

But this one is a little tricky. In danish code, section 802 refers to areas with such installations ( outdoor applications where exposed to rain or exposed to mist) 

In horticulture section in danish code says it is necessary to have I44. 

Even outside the specific confines of a special installation or location, a designer will be responsible for ensuring the electrical equipment selected meets the external influences that could reasonably be foreseeable. 522 refers.

Could you put boxes over the existing DBs? For example these www.tlc-direct.co.uk/.../WKWDB7.html with the back cut out and screwed to the wall.