Reefer container issue - need assist

[nightstriker]

Hi all, just need your assistance. as i've a case that shipper get un professional technician and played with the reefer equipment of the carrier. after my reefer contractor checked the container he advised below. so can anybody advise if below is true and could be done

============quote================
We found that the customer has actually played with the unit’s control wiring which has resulted by having the evaporator motors rotating in the wrong direction, we have repaired the wiring and the evaporator motors has returned to their normal rotating direction!

The negative results which we may have resulted if the container is kept by the wrong wiring: having the supply air going UP instead of DOWN and accordingly the supply air sensor will be reading the return air temperature and the return sensor will be reading the supply temperature, and cargo will never reach the setpoint!!!

On the display you will see that the unit is inrange and achieving the setpoint and everything is normal, but actually this is a fake readings resulting from having the motors rotating in the reverse direction..

It’s totally not recommended to let the customers play with our reefers..

===========unquote========================

[Brian_UK]

Seems reasonable but what is it that you want us to say, your contractor has said it all, or am I missing something?

[monkey spanners]

If the fans are three phase then they could easily be made to run backwards, if they are single phase then its still possible to do (and i have seen it done with both three phase and single phase fans on condensers).
What your contractor said sounds technically feasible, but i don't work on containers so can't say for sure.

[djbe]

Yes it could be done, but cannot explain why it would be done.

I would guess a more likely explanation is that the unit was running backwards via the 3 phase supply.

This is a simple check that needs to be made when first connecting the unit to mains supply.

The condenser fan should blow air outwards, the evaporator fans should draw air from the top and blow down through the floor outlets.