scutworth
24-12-2009, 10:22 AM
We have developed a problem with our YDAJ77XT9 York Millenium Recip chiller system. We currently operate only systems 1 & 2 (systems 3 and 4 have been out of action for years, but we don't need more than two systems).
Our setpoint for water leaving temp is -5C (30% glycol), but we are unable to achieve it because system 2 will not kick in. When system 1 runs as lead compressor (normal operation), we get a "NO COOLING LOAD" message and the system refuses to start then gives us a low oil pressure error. We changed the lead to system 2 to see what would happen and it again refused to start, giving a low oil pressure message. System 1 started shortly afterwards. Systems 1's pressure look to be fine, but system 2 is obviously not giving us anything useful as it is not starting. I believe that the solenoid activates, but the compressor doesn't receive the start signal.
Our service engineers seem to think the problem is related to one of the circuit boards, but our control engineer is convinced that the compressor itself is the problem. If it is indeed the circuit board, we don't know how to determine whether it is the main EPROM board or one of the subsidiary boards.
Can anyone offer any advice as to likely cause, possible solutions and, if the boards are the problem, how to diagnose which one it is?
Thanks in advance.
Our setpoint for water leaving temp is -5C (30% glycol), but we are unable to achieve it because system 2 will not kick in. When system 1 runs as lead compressor (normal operation), we get a "NO COOLING LOAD" message and the system refuses to start then gives us a low oil pressure error. We changed the lead to system 2 to see what would happen and it again refused to start, giving a low oil pressure message. System 1 started shortly afterwards. Systems 1's pressure look to be fine, but system 2 is obviously not giving us anything useful as it is not starting. I believe that the solenoid activates, but the compressor doesn't receive the start signal.
Our service engineers seem to think the problem is related to one of the circuit boards, but our control engineer is convinced that the compressor itself is the problem. If it is indeed the circuit board, we don't know how to determine whether it is the main EPROM board or one of the subsidiary boards.
Can anyone offer any advice as to likely cause, possible solutions and, if the boards are the problem, how to diagnose which one it is?
Thanks in advance.