On the display
The control center — the OptiView Touchscreen Control Center — shows the message exactly as VSD - Precharge - Low DC bus voltage, and the manual prints no other form of this text. It is one of the medium voltage variable speed drive (VSD) cycling fault messages and is generated during the drive's precharge sequence.
What it means
During precharge, the drive compares all of the DC bus voltages against a threshold of 330 VDC, which the manual gives as 20% of 1,650 VDC. The comparison is made 0.5 s after initiation of precharge. This message means that, at that check, the DC bus voltages did not meet or exceed the 330 VDC threshold. In response, the drive initiates a cycling shutdown.
Why it appears
- The DC bus voltages did not meet or exceed the 330 VDC threshold at the check performed 0.5 s after precharge was initiated — this is the only cause the manual states for the message.
Setpoints and thresholds
- Precharge DC bus voltage threshold: 330 VDC (20% of 1,650 VDC).
- Check timing: 0.5 s after initiation of precharge.
Reset and restart
No manual reset is described for this message. Messages automatically clear when the fault condition no longer exists; if the chiller was running when the fault occurred, it automatically restarts.
Questions engineers ask
What does VSD - Precharge - Low DC bus voltage mean on a YORK YK?
During precharge the drive checks the DC bus voltages against a 330 VDC threshold, 0.5 s after precharge begins. The message means the DC bus voltages did not meet or exceed that threshold, and the drive initiates a cycling shutdown.
How do I clear the VSD - Precharge - Low DC bus voltage message?
No manual reset is described. The message clears automatically when the fault condition no longer exists, and a chiller that was running when the fault occurred restarts by itself.
What DC bus voltage threshold applies during precharge?
The threshold is 330 VDC, which the manual gives as 20% of 1,650 VDC. The drive checks it 0.5 s after initiation of precharge.
Messages next to this one
Source
Written from the manufacturer's manuals for the YORK YK; every number and designation on this page is checked against them before publication. The row of the manual this message comes from:
All YORK YK messages: fault codes · YORK YK documentation · YORK manuals