15 Evaporator Fan Low Speed Current Too Low MP4000

Description 

Evaporator Fan Low Speed Current Too Low 

• Occurs during pretrip (PTI) or function test only. 
• Fan power consumption is 33% below expected current draw or phase current level differs 33% or more. 
• If both alarm #14 and #15 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 below approximately 
• - 0,5Amp@400VAC/50Hz 
• - 0,6Amp@460VAC/60Hz 
• With 40’ setting below approximately 
• - 0,5Amp@400VAC/50Hz 
• - 0,6Amp@460VAC/60Hz 
• Indicates: 
• Defective or open fan motor internal over temperature protection switch. 
• 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 low speed. Make sure all fans start on low speed. If a motor does not start and is very hot, wait 10 minutes for internal over temperature switch to close. 
• 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 
• - 0,8Amp@400VAC/50Hz 
• - 0,9Amp@460VAC/60Hz 
• With 40’ setting expect 
• - 0,8Amp@400VAC/50Hz 
• - 0,9Amp@460VAC/60Hz