Under Draft or Combustion Air Pressure Fault

 

Cause: The fan is unable to bring the actual pressure to the CPC-3 set

             point.

 

Solution: Check to see if the VFD displays a fault message. If so, refer to the VFD Fault page. If not, verify the transducer is properly functioning.

 

NOTE: Transducer sensing tube connections:

               TD-2 for Draft = tube on LO, HI left open to room

               TD-2 for Sealed Combustion Air = tube on LO, HI left open to room

               TD-3 for Open Combustion Air = tube on LO, high left open to room

 

               To verify Transducer voltage is adjusted properly, disconnect sensing

               tube from port.

 

               Voltage present across G (positive meter lead) & B (negative meter

               lead):

               TD-2 = 2.79 VDC

               TD-3 = 5.5 VDC

 

               Voltage present across R (positive meter lead) & B (negative meter

               lead):

               24 VDC on both TD-2 and TD-3