Sitting on the fence here,but the call to j+e hall regarding the duty should provide results I have no faith in wholesalers of equipment they use guess work in my opinion well at least some do and leave the fridge tech high and dry for slaughter,better to over compensate in my opinion the days of honest wholesalers has gone they just want a sale with no comebacks but you can sue them quite easily for losses,always make sure you give the correct load requirements both in email and letter so they can not argue phone calls don't stand up in court I am about to start legal action which will if I win shut a rogue wholesaler down,they supplied equipment that yes would do the requirements unfortunately did not and put lives at risk,my public liability company has started the proceedings on my behalf!