Checked four Changeair heat pump units #8, #13, #14 and #16 for no cool. Found #16 tripping off on high pressure due to no condenser fan operation. Found the ecm on the condenser fan not receiving the proper 2-10 vdc signal to run. Found the plug in the condenser section for the dc signal failed. Removed the plug and direct connected the wires. Started the unit and verified operation. Found the other three units with the same issue. Removed the plugs and direct connected the wires. Verified operation. Took pictures and sent the failed plugs to the service department at Changeair per their request.
Checked the nineteen Change-air units for the Grade School for burnt wiring harness connections. Found eight plugs burnt at the 460 volt connections. Removed the damaged plugs and direct wired the wires. Made a list of the repairs, took pictures of the damaged plugs and sent the info to Travis Laver as requested.
Checked the high school music room Rtu for no cool. Found the blower belt loose causing poor air flow and freeze stat trippage. Replaced the belt and verified operation. Belt was customer provided.
Checked the Grade school teachers lounge for no cool from the Changeair unit . Found two fuses blown due to a shorted wiring harness going to the condenser fan. Repaired the wiring, replaced the fuses and verified operation. Also checked the Grade school office for no cool from the Changeair unit. Found two blown fuses due to a shorted wiring harness going to the 460 x 240 volt transformer. Repaired the wiring, replaced the fuses and verified operation. The factory harnesses have 460 volts thru the connections allowing arching and fuse failures. Customer requested looking at all 19 units when time allows to check the harnesses for the same issues. Will schedule the requested work.
Checked six units for the grade school and high school of comfort complaints. Found the Change-air unit #6 void of refrigerant. Repaired the leak and recharged the system. Found the Change-air unit #10 with a low discharge temp due to plugged filters. Replaced the filters and verified operation. Found the Change-air unit #12 with a blown fuse to the controls. Replaced the fuse and verified operation. Found the Change-air unit #16 with the compressor lockout temp at 70 deg holding off the compressor. Set the outdoor lockout to 35 deg to match the others in the system. Verified operation. Reset the Trane controls for the high school Rtus #12 and #14 and verified operation. Both units were not receiving a cooling call from the system before resetting with the room temps 5-6 deg above setpoint.
Checked the Rtu #12 for the high school for no cool. Found the Trane Ems not calling for cool at the unit. Found the control in occupied off mode. Changed the setpoint to occupied auto and found the unit cooling normal. Also checked the split for Mrs. Davenports annex classroom for no cool. Found the system low on charge. Added R-22 to the proper charge. Found the schrader caps loose with oil show at the suction line. Leak searched the system after charging and found no leaks. Verified that the caps were tight after recharging.
Replaced the evaporator fan motor in the two door reach in cooler in the storage room of the kitchen. Verified operation after repairs.
Checked the split system for Mrs. Pool's classroom in the Annex for no cool. Found the condenser fan motor locked up. Replaced the motor. Verified operation. Also checked the two door reach in cooler for the kitchen storage room for too warm. Found the evaporator fan running slow causing poor air flow accross the evaporator. Removed the motor. Will pick up a new motor and return to finish the repair.