On the display
The panel shows the text VSD - LINE VOLTAGE PHASE ROTATION. The manuals print the message in this one form only, so there are no display variants to watch for. It belongs to the VSD fault messages of this chiller and is listed in the control's table of safety shutdown messages.
What it means
On this chiller the message means that the internal phase rotation determinations disagree. The input of the drive is not sensitive to the phase rotation of the input voltage, but internally to the drive the rotation must remain the same — so the VSD has to work out the correct input rotation on its own. For this purpose there are two methods within the VSD logic board to determine the line voltage phase rotation. When these two methods do not report the same phase rotation, the logic board cannot establish the correct rotation and this shutdown occurs.
Why it appears
- The input voltage to the VSD is not phase rotation sensitive, but the VSD must be able to determine the correct input phase rotation; the shutdown is generated when the VSD logic board cannot determine the correct phase rotation.
- The output of the line voltage isolation board cannot show CBA rotation when the input voltage to the drive is really ABC rotation.
- The two methods within the VSD logic board for determining the line voltage phase rotation do not report the same phase rotation.
Reset and restart
Although the message is listed with the safety shutdown messages, it no longer behaves like one: a change made at the request of Field and PTS reclassified it — previously this fault condition required a manual reset, and it is now a Cycling Fault.
Recovery is stated by the control manual: When this condition clears, the chiller can be started after the clear faults button is pressed.
Questions engineers ask
What does VSD - LINE VOLTAGE PHASE ROTATION mean on a YORK YMC2?
It means the two methods inside the VSD logic board that determine the line voltage phase rotation do not report the same rotation, so the logic board cannot determine the correct input phase rotation and the shutdown is generated.
Why does the YMC2 shut down on phase rotation if the drive input is not rotation sensitive?
The input of the drive is not sensitive to the phase rotation of the input voltage, but internally to the drive the rotation must remain the same, so the VSD must determine the rotation itself — and it shuts down when its two determination methods disagree.
How is the YORK YMC2 VSD - LINE VOLTAGE PHASE ROTATION fault cleared?
When the condition clears, the chiller can be started after the clear faults button is pressed. The fault was changed at the request of Field and PTS from a condition requiring a manual reset to a Cycling Fault.
Is VSD - LINE VOLTAGE PHASE ROTATION a safety fault on the YMC2?
It is listed among the chiller's safety shutdown messages, but it was changed to a Cycling Fault; previously this fault condition required a manual reset.
Messages next to this one
Source
Written from the manufacturer's manuals for the YORK YMC2; every number and designation on this page is checked against them before publication. The row of the manual this message comes from:
All YORK YMC2 messages: fault codes · YORK YMC2 documentation · YORK manuals