On the display
The OptiView Control Center shows VSD - DC bus voltage imbalance as one of the variable speed compressor drive cycling fault messages. The manual prints the message in this single form and lists no other wording for it.
What it means
The message applies to TM, VSD, and LVSD model drives. The VSD DC bus voltage is continuously monitored, and this message is displayed when the 1/2 bus voltage is not within ±88 VDC for a 400 VAC to 460 VAC line, or ±106 VDC for a 575 VAC line, of 1/2 of the total bus voltage. In other words, one half of the drive's DC bus has moved too far from half the total bus voltage for the line voltage in use.
Why it appears
- The fault table gives one cause: the 1/2 bus voltage is not within ±88 VDC on a 400 VAC to 460 VAC line, or ±106 VDC on a 575 VAC line, of 1/2 of the total bus voltage. The manual lists no other causes for this message.
Setpoints and thresholds
- 400 VAC to 460 VAC line: the 1/2 bus voltage must stay within ±88 VDC of 1/2 of the total bus voltage.
- 575 VAC line: the 1/2 bus voltage must stay within ±106 VDC of 1/2 of the total bus voltage.
- The VSD DC bus voltage is monitored continuously.
Questions engineers ask
What does VSD - DC bus voltage imbalance mean on a YORK YK chiller?
It is a variable speed compressor drive cycling fault for TM, VSD, and LVSD model drives. It is displayed when the 1/2 bus voltage is not within ±88 VDC for a 400 VAC to 460 VAC line, or ±106 VDC for a 575 VAC line, of 1/2 of the total bus voltage.
What is the DC bus imbalance limit on a 575 VAC YK?
For a 575 VAC line, the 1/2 bus voltage must stay within ±106 VDC of 1/2 of the total bus voltage. Outside that band, the message is displayed.
Which drives monitor the DC bus for this fault?
TM, VSD, and LVSD model drives. The manual states that the VSD DC bus voltage is continuously monitored on these models.
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