We run ours at +2 for chilled and -22 for frozen but as the others have said, check if unsure.
Wiretwister:
I disagree. The box temperature will fluctuate, the thermostat is in the box chamber, the product will not vary by the same degree.
I do agree with your point Wiretwister, but I wish you good luck in your attempt to get your point across to the arsey goods in clerk who’s studying your printout and shaking his head. My point is why create problems where none exist?
Its easier to sleep when its on continuous run!
So, OP, what did you do in the end?
OP went on flats instead, just waiting for the “how do you tie a dolly knot” and “which way up does a fly sheet go” posts 
Soz just joking, hope it wen’t smoothly on the reefers 
^^^ Know just the man for that, lives in ■■■■■■■
the maoster:
Wiretwister:
I disagree. The box temperature will fluctuate, the thermostat is in the box chamber, the product will not vary by the same degree.I do agree with your point Wiretwister, but I wish you good luck in your attempt to get your point across to the arsey goods in clerk who’s studying your printout and shaking his head. My point is why create problems where none exist?
My stock answer to that is to get the receiver to probe the product. I was once kept waiting for nearly 2 hours while the probe was done and the perceived problem was discussed at a higher level before being accepted.
In my current job I will often put toilet rolls/Crisps in the freezer compartment to fill a row and support the adjacent pallets because they are mostly air it never causes a problem. Try it with pop or product in jars and the chances of the temperature coming down are very remote. The chances of damaging the product is quite high.
Santa:
Leaving it on continuous keeps the chilled air blasting out onto the front pallets. If they are tender produce, this can ruin them.Every customer has their own ideas about the ‘correct’ temperature. Ambient produce is usually at +4, but I had people who wanted it at +6 or +2.
One other thing. I was once sent out with a frozen load and then on to pick up fruit. In the hour between drop and load, the fridge went up to +10, but when I got back the load was ruined because the floor and walls were still sub zero. Not my mistake, but a more experienced driver would have told the planner - no can do.
If you’ve just dropped a frozen load, and you’re on the way to pick up a chilled one - don’t you set the fridge to +10 and run it - to thaw out the trailer itself?
Besides, I don’t want to be slipping arse-over-head because there’s still ice on the floor. I’d rather just wade through the pools of water one gets, with it’s confirming that the trailer is fully “above 0%” now… 