isotherm ITC electronic termostat instalation

[alexp606]

I have bought this new modern unit to upgrade my 12 years sailboat 12V icebox instalation equipped with Danfoss BD50F compressor (upgraded from original BD35F few years ago),VD16/15 inside box evaporator with fan, and Seacop 101N0212 electric panel.
The original thermostat ia a mechanical one
with just basic rotarry knob control,no display, and it's long thin metal tube temp sensor originally installed since new very near and touching the evaporator.
this thermostat doesn't work well now, the inside temp cycling between 34-50 F ,no matter the knob position.
By this new Isotherm ITC unit manual, the ITC temp sensor should be mounted "as far away from evaporator"..but the basic drawing in manual showing it's location , shows a small home like fridge box whitout inside evaporator..
so I am not sure if it should be mounted "as far away from evaporator".. or very near the evaporator as original present mechanical termostat is located..??
(I wrote a mail to Isotherm but got no reply).
Thanks for assistance ,Alex

[GordMay]

Greetings and welcome aboard the CF, Alex.

[alexp606]

Thanks[emoji2]

[Richard Kollmann]

Originally Posted by alexp606

I have bought this new modern unit to upgrade my 12 years sailboat 12V icebox instalation equipped with Danfoss BD50F compressor (upgraded from original BD35F few years ago),VD16/15 inside box evaporator with fan, and Seacop 101N0212 electric panel.
The original thermostat ia a mechanical one
with just basic rotarry knob control,no display, and it's long thin metal tube temp sensor originally installed since new very near and touching the evaporator.
this thermostat doesn't work well now, the inside temp cycling between 34-50 F ,no matter the knob position.
By this new Isotherm ITC unit manual, the ITC temp sensor should be mounted "as far away from evaporator"..but the basic drawing in manual showing it's location , shows a small home like fridge box whitout inside evaporator..
so I am not sure if it should be mounted "as far away from evaporator".. or very near the evaporator as original present mechanical termostat is located..??
(I wrote a mail to Isotherm but got no reply).
Thanks for assistance ,Alex

If I understand your system correctly the evaporators are Adler Barbour/WAECO fan cooled and are designed for a thermostat that controls evaporator fan air temperature zero to +25 degrees F and an OFF ON deferential of 10 to 20 degrees.

The problem with the Isotherm ITC is it is an area thermostat functioning to control box temperature and not evaporator temperature. Normally when controlling box area temperatures the OFF ON differential is much less then ten degrees F. Look and see if the ITC differential is adjustable, if so set control temperature to desired box say 35 degrees and differential to less than 5 degrees.

I have to point out that these fan cooled evaporators are not self defrosting an depend on frost melting during compressor OFF cycles, or very frequent manual defrosting.

[alexp606]

Thanks for your reply.Yes,ITC is adjustable.but where do you advise to locate the temp sensor,away from evaporator, or very near it-as the mechanical basic present unit?

[Richard Kollmann]

Originally Posted by alexp606

Thanks for your reply.Yes,ITC is adjustable.but where do you advise to locate the temp sensor,away from evaporator, or very near it-as the mechanical basic present unit?

Thermostat sense tube in the top third of box any where natural air is tumbling, heat rises and cold descends. Hopefully the fan evaporator is mounted high in the box.
A good lid or door seal compressed will reduce moist air infiltration reducing evaporator frosting.

[alexp606]

Thanks for your healpfull advise.