Tech found rtu 1 and rtu 2 thermostats were both off. Tech went to roof and smelled burnt smell from the middle unit rtu2. Tech removed cover and found middle contactor was burnt high voltage. That is for circuit 1 tech meged compressor and found both circuits meged red. Tech found 2 time delay fuses were blown as well as one for the heat strip block. Tech found in disconnect 3 80amp fuses the middle one was blown. Tech went to breaker 125amp and reset breaker . Tech measured power to all legs to each other and to ground. They are within specs. Tech found transformers are at 230 tap low voltage was 23v. Tech tapped to 208v tap on transformers and low voltage went to 26v. RTU1 system has a popped transformer fuse. Tech reset fuse system started up tech cycled system on heat cool and all are operating properly. Tech did have to lower transformer from 230v to 208v low voltage changed as well 23v to 26v. System 1 is operating. Tech will return to continue to diagnose on rtu 2. Rtu 1 tech f
-Performed service call stating all 3 systems thermostats were blank and systems not functioning. Observed repairs being made at nearby power lines when arriving at location. Area experienced stormy weather recently. -Upon arrival, found systems 1 & 2 thermostats blank. Staff states they were able to operate system 3 yesterday. -System 1 blower motor operating upon arrival but thermostat still blank. Verified low voltage at thermostat location. Thermostat in need of replacement. Used Vision Pro 8000 for 2 stage heat pump with auxiliary heat. Matched field wiring to original thermostat. -System 2 transformer breaker was tripped upon arrival. Reset breaker and verified high and low voltage. Unit short cycles with call from thermostat. Found Y2 (compressor 2) contactor shorted and in need of replacement. System operates correctly with contactor replaced. 2 pole 40 A. Y1 contactor was recently replaced. -System 3 operational. -Left thermostats set to cool mode 74 degrees fan on, per s
Returned to diagnose 2 RTUs. Front system #1 is operating properly upon thermostat call, proper delta T is acquired. Belt is tight up to specs, no abnormal noise was detected throughout visit. System #2 (middle) has a shorted 2 pole compressor contactor, the reason for the transformer to trip upon a Y( compressor) call. Tech was unable to contact kris. Bruce approved the repairs for system #2. Tested system In cooling from the thermostat and both compressors operated properly. System is back cooling.
-Performed CMA Full Service on 3 rooftop package units. -System 1 (Front): Thermostat setting not satisfied upon arrival. Blower motor belt loose and noisy in operation. Tightened belt as appropriate. Observed blower contactor erratic operation when jumping R circuit to blower circuit. Found 24v from transformer but little to no voltage at thermostat connections to control board. Suspect problems with control board. Recommend demand tech to further diagnose system. -System 2 (middle): Observed fan running all day but no operation of compressors. Observed & removed wasp nest across high voltage fuses. Observed 24v between R and common thermostat wire on control board but no voltage on Y circuit even though thermostat should be calling. Jumping R to Y causes transformer breaker to trip. Recommend demand tech to further diagnose system. -Summary: System 3 operating correctly at this time. Demand tech being dispatched to identify problems with systems 1 & 2.
Wiring on old motor: Blue goes to BR/T9&O/T3 Yellow goes to R\T8&TanT2 Blk goes to pinkT7&bluT1 Tech replaced failed belt driven motor on RTU2. After repair, tech found no voltage in disconnect. Tech also found front RTU1 with no voltage in disconnect. Tech found breakers for both RTU 1 and 2 in the off position. Tech turned 125 amp breakers for both RTUs back on in the back electrical room. RTU2 is back heating correctly after replacing blower motor. Tech noticed no G call for electric heat strips on recently replaced customer supplied tstat. Tech corrected install setup menu. System is heating correctly with G and W1 call. System is 2 cool/1 heat conventional heat strip. Not a heat pump or gas pack. RTU1 blower motor turned on, but heat strips did not run due to a blown 60 amp line voltage fuse. Tech replaced fuse for testing purposes. Called Bruce who approved service call and fuse replacement by phone. All 3 RTUs are back running.
Upon arrival customer stated recently replaced thermostat is blank and other two thermostats are not cutting system on and Wi-Fi disconnects. Tech disabled Wi-Fi feature on these thermostats and tested both systems, both systems came on and ran properly. Blank thermostat has 0v, tech was unable to go on rooftop to further diagnose due to weather. Will have to call and schedule a time for us to come back out and further diagnose system.
Tech installed a costumer supplied thermostat. Costumer initially had 2 thermostats to install, due to one being a wireless red link thermostat, only one thermostat was able to be replaced. All 3 systems are operating properly, manager on duty approved the repairs.
Found the middle unit with thermostat off, system is sending 24v to the thermostat but no display. Bad thermostat was diagnosed. Costumer stated that he will order his own thermostat and install it himself. Collected house call fee. Pictures of the Model and serial number of the units were taken. Each unit has 4 16x16x2 pleated filters.