12 Evaporator Fan High Speed Current Too High MP4000

Description 

Evaporator Fan High Speed Current Too High 

• Occurs during pretrip (PTI) or function test only. 
• Fan power consumption is 33% above expected current draw or phase current level differs 33% or more. 
• If both alarm #12 and #13 is active this indicates too high phase difference. 
• Expected fan current is a function of the power line frequency and the supply voltage. 
• With 20’ setting above approximately 
• - 3,4Amp@400VAC/50Hz 
• - 4,2Amp@460VAC/60Hz 
• With 40’ setting above approximately 
• - 2,7Amp@400VAC/50Hz 
• - 3,4Amp@460VAC/60Hz 
• Indicates: 
• Defective or stuck evaporator fan motor. 
• Incorrect motor or motor connections. 
• Defective volt or amp meter on power module. 

Corrective Action 

• Open evaporator door and make sure all fans rotate freely. 
• Enter Manual Function Test and start evaporator fans on high speed. Make sure all fans start on high speed. Check fan motor volts and amps. 
• With 20’ setting expect 
• - 2,4Amp@400VAC/50Hz 
• - 3,1Amp@460VAC/60Hz 
• With 40’ setting expect 
• - 1,8Amp@400VAC/50Hz 
• - 2,4Amp@460VAC/60Hz