BS 7671 Section 717 - Mobile or Transportable Units. Applicable to refrigeration trailers?

Does a refrigeration trailer that is utilised to transport food goods between the clients depots and is then connected into the sites electrical supply through a trailer hook up connection unit to facilitate running of the refrigeration equipment classified as "Mobile or Transportable Unit" and therefore warrant the requirements of BS 7671 Section 717?  

The trailer will maintain the connection to the sites power supply for a few hours to facilitate loading/unloading. 

The regulations now adds further detail for PME installations, where it can only be permitted if one of the below applies: 

  

Would part (ii) be a satisfactory measure in the above scenario for a PME supply? 

Parents
  • Where trailer plug-in facilities are provided at trailer docks as represented in the photo, here, at least, they are normally on TN-S simply because the site normally has its own tx due to the significant current demand refrigeration plant requires.

Reply
  • Where trailer plug-in facilities are provided at trailer docks as represented in the photo, here, at least, they are normally on TN-S simply because the site normally has its own tx due to the significant current demand refrigeration plant requires.

Children
  • at least, they are normally on TN-S simply because the site normally has its own tx

    And whilst the basic EV charging guidance is "treat TN-S in the public supply like PME" the guidance also states that if you have TN-S from a private a transformer, this can (and should) be treated as TN-S and NOT PME.