williams blast chiller electric defrost heater question

[Contactor]

hi everyone

can anyone tell me if electric defrost heaters have been known to fail in such a way that they are still working but not getting hot enough, i.e an increase in resistance?

thanks

it's a williams blast chiller circa 1991 not defrosting

[icecube51]

what type of heater do you meane?
mono fase or triple fase?

by triple fase its posible, mono it works or don't.

Ice

[Contactor]

thanks, it's mono.

didn't know you could get triple

[monkey spanners]

On bigger evaps they run the defrost heaters off three phase, one phase per heater strip.

What is the problem? Could be a faulty evap probe if it is not clearing all the ice on defrost, probe tells the controller evap is toasty warm when its still frosty.

With the heater you could measure the current it pulls and work out the wattage and ask Williams how many watts a new one should be.

Jon