On the display
The panel shows VSD - Precharge - Low DC bus voltage 2. The manual lists it among the variable speed compressor drive cycling fault messages, and it applies to all model drives. It is a shutdown message: when the condition described below is not met, this shutdown is generated
.
What it means
Near the end of precharge, the DC link voltage must reach at least the high threshold, which is determined by the line voltage setpoint, within 20 s after the precharge signal has been commanded. If the DC link voltage does not reach that threshold inside the 20 s window, the drive generates this shutdown. Which threshold applies depends on the line voltage setpoint configured for the drive — the values are listed under Settings.
Why it appears
- The DC link voltage did not reach at least the high threshold — determined by the line voltage setpoint — within 20 s after the precharge signal was commanded. This is the only trigger the manual gives for the message.
Setpoints and thresholds
- Line voltage setpoint 380-415 VAC: the DC link voltage must reach at least 414 VDC.
- Line voltage setpoint 460 VAC: the DC link voltage must reach at least 500 VDC.
- Line voltage setpoint 575 VAC: the DC link voltage must reach at least 600 VDC.
- The threshold must be reached within 20 s after the precharge signal has been commanded.
Reset and restart
The manual describes no manual reset step for this message; recovery is automatic. The VSD logic board times for 10 s before clearing the fault and allowing another precharge to start.
The VSD fans and water pumps remain energized during this wait. The VSD logic board allows up to three consecutive precharge-related faults; after the third consecutive precharge-related fault, the safety shutdown message VSD - Precharge lockout is generated.
Questions engineers ask
What does VSD - Precharge - Low DC bus voltage 2 mean on a YORK YK?
Near the end of precharge, the DC link voltage must reach at least the high threshold set by the line voltage setpoint within 20 s after the precharge signal is commanded. If it does not, the drive generates this shutdown.
What DC bus voltage threshold applies at 460 VAC?
For a 460 VAC line voltage setpoint, the DC link voltage must reach at least 500 VDC. The other thresholds are 414 VDC for 380-415 VAC and 600 VDC for 575 VAC.
How does the YORK YK recover from this fault?
Automatically: the VSD logic board waits 10 s, then clears the fault and allows another precharge to start, with the VSD fans and water pumps remaining energized. Up to three consecutive precharge-related faults are allowed; after the third, the VSD - Precharge lockout safety shutdown is generated.
How many precharge faults cause a lockout on a YORK YK?
Three. After the third consecutive precharge-related fault, the safety shutdown message VSD - Precharge lockout is generated.
Messages next to this one
The same message on other models
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