Evaporator Fan Trouble

[Bertreb]

We have newly installed 6 units -25C cold storage rooms equipped with R507A condensing unit using semi-hermetic type compressor. The unit cooler is at -30 deg. C evaporative temperature and mounted with 2 units fan and electric deforst equipment. The cold storages were tested and commissioned 10 months ago and operating smoothly. Recently we have problem maintaining the design room temperature. Per inspection conducted we found out that 1 of the 2 fans is not working but the control circuit did not tripped off. To test fixing the problem we removed the left side cover of the evaporator and the fan in question runs but when we re-attached the side cover again it stops again and only 1 fan is working. What do you think the problem with the fan or unit cooler? Any suggestions to locate the defects and fix the trouble?

[frederik79]

220 fan 380 fan ?

[DEVIL]

Hello

You might have loose wires and when u moved the cover it made contact or the cover is sectioning the wire, and the same happens with the contact, or the cover touches the fan blades

[taz24]

We have newly installed 6 units -25C cold storage rooms equipped with R507A condensing unit using semi-hermetic type compressor. The unit cooler is at -30 deg. C evaporative temperature and mounted with 2 units fan and electric deforst equipment. The cold storages were tested and commissioned 10 months ago and operating smoothly. Recently we have problem maintaining the design room temperature. Per inspection conducted we found out that 1 of the 2 fans is not working but the control circuit did not tripped off. To test fixing the problem we removed the left side cover of the evaporator and the fan in question runs but when we re-attached the side cover again it stops again and only 1 fan is working. What do you think the problem with the fan or unit cooler? Any suggestions to locate the defects and fix the trouble?


It could be one of a few points.

Are the fans in independant chambers, are they seperated from each other.

The fan may have failed and not caused they circuit breaker to trip and then
you may be seeing the fan run in the air flow of the other fan.

Is the fan running at full speed?

Is the fan running in the correct direction?

If it is a single phase fan motor the fault could be the start capacitor, which stops
the fan running but it will flow backwards in the draft of the other fan and then gain
enough speed to start, but in reverse.

It could be an electrical fault, a bad conection or somthing.

Check the cable from the junction box to the motor, check to see if the cable has
been damaged.

You need to test the motor electricaly, test for open circuits. If the motor is faulty
and the circuit is still intact, it could point towards an open circuit.

All the best

taz

.

[Bertreb]

The fan is 220VAC, single phase

[Bertreb]

It could be one of a few points.

Are the fans in independant chambers, are they seperated from each other.

The fan may have failed and not caused they circuit breaker to trip and then
you may be seeing the fan run in the air flow of the other fan.

Is the fan running at full speed?

Is the fan running in the correct direction?

If it is a single phase fan motor the fault could be the start capacitor, which stops
the fan running but it will flow backwards in the draft of the other fan and then gain
enough speed to start, but in reverse.

It could be an electrical fault, a bad conection or somthing.

Check the cable from the junction box to the motor, check to see if the cable has
been damaged.

You need to test the motor electricaly, test for open circuits. If the motor is faulty
and the circuit is still intact, it could point towards an open circuit.

All the best

taz

.
The fan motor is single phase, operating indepently and running at full spped.I'll re-check & test it again.
Thanks Taz.

[US Iceman]

Is the coil completely defrosted? Ive seen fans stop and run backward because of this. If one chamber of the evaporator is frosted shut or blocked with ice, the adjacent fan can cause the fan on the blocked chamber to stop and then reverse. Looking at it is difficult to establish.

What tipped me off is when you said you removed the panel and the fan worked fine, but then stopped when you replaced the panel.

If might be something else, but you should check this.

[Bertreb]

Thanks for the reply ice man, i'll have it check again.

bertreb