electronic defrost

[sork]

hi guys
i am working on coldstore on r 404a temp -20 c
unit operates normally in ref cycle but when it goes to defrost cycle ( electric heater) it remains in defrost the room temp rises to +50 c and more.
unit is controlled by master cella (carel) electronic controller.
any idea???????????
cheers
sork

[Brian_UK]

Is the room temperature actually rising or just the area where the sensor is?

If the cold store really went up to 50°C then the store would have been wrecked by now.

[smpsmp45]

You shall have to adjust the timer in that to suit your requirements. Since the temp you mentioned is 50 Deg C, It must be the Heater temp as the sensor must be near to this. So in all probability the icing must be very small or the frequency of the defrost is high.

Reduce the frequency of the defrost cycle. & change the termination stat temperature

[mcunliffe4]

check probe position check de-frost parameter ie. endurace time

[sokold]

hi all, i would check the following things:

defrost termination temp....no more than 23C
defrost duration................30 mins
defrost frequency..............every 4 hours
drip time..........................2 mins

it sounds like you have the termination temp too high and its cooking the coil

[littleyapper]

i think all above are right if THE EVAP PROBE IS INDEED THE EVAP PROBE... me thinks you have them upmixed

[chemi-cool]

i think all above are right if THE EVAP PROBE IS INDEED THE EVAP PROBE... me thinks you have them up mixed

Sounds right to me, also the controller is faulty. It doe's happening to them sometimes.

[sork]

thank you guys , your advise been very helpfull.
running the system to see how it performs.

[Mark-Cool-IT]

you would need to check your settings on defost termanation .should end at about 5 c hope this this helps