I have had involvement in many installations from small spaces to a
national monument.
Gallery installations are by their very nature unusual, and often involve aspects that are outside the scope or experience of routine procedures and those who implement them.
Every place will have their own rules, which can be based on any or all of experience, common sense or extreme Health & Safety paranoia and a 'No' mentality.
Here's what I've learnt :
1) Theory vs. practice : You may be given lists of requirements ranging from zero to ridiculous, requests for method statements, risk assessments, PAT labels, yadayadayada, but when it comes to actually setting up, everybody is so busy getting everything done on time that they are either too busy to look at anything in any detail, or don't care.
I have NEVER EVER had anyone check on any safety aspect of an installation, regardless of the level of preceding paperwork, most of which is simply ass-covering for them. In some cases I've had to tell them that
their equipment/facilities are unsafe or unsuitable.
2) Don't ask/Don't tell - If you are doing anything 'unusual', don't volunteer any info that they don't ask for - it will only confuse them and give them a reason to say 'no'. Do however make sure you clearly state
in writing (and get acknowledgement) anything they need to do, for both safety and functionality - provision of power, barriers, supervision, staff training, lighting, signage etc.
3) The people on the ground doing construction etc. are typically way more helpful than management.
4) Take spares of EVERYTHING, and tools to swap or repair any part of your stuff. And lots of cable ties and gaffer tape. Know in advance the locations of the nearest RS/Screwfix/B&Q or whatever. And make sure the budget has some contingency provision for last-minute unexpected requirements.
Bottom line - as long you are competent, and happy that what you are doing is safe for the environment
* there is unlikely to be any problem, but make sure you look like you know what you're doing, and have good answers ready for any questions that may arise.
A pack of PAT test labels from ebay is a good investment.
* Note that you may not become fully aware of all details of the environment until you get there to install. A site visit beforehand is invaluable for spotting potential problems. At the very least insist on photos of the space.