ACQUITY UPLC H-Class shows "APH active but not present" error - WKB83947

SYMPTOMS

• "APH active but not present" error seen for one column position
• LC runs do not start

ENVIRONMENT

• UNIFI Network
• ACQUITY UPLC H-Class
• ACQUITY UPLC Column Manager

CAUSE

A 30-cm column oven and a column manager are installed. Column manager is configured in 4-column mode but has only two APH installed. Position 4 from the column manager inlet pod runs to the 30-cm column manager. APH for positon 4 is set to active.

FIX or WORKAROUND

1. Set APH 4 to "Present Passive".
2. Set APH 4 to "Present Passive" in the Column manager section of the LC method.

ADDITIONAL INFORMATION

APH and column temperature for the 30-cm column oven are set in the sample manager console page. The column manager has only two column positions plumbed. The outlet for position 4 is plumbed to the 30-cm column oven. The column manager must be configured for four positions to allow for column 4 to be selected. This allows flow to the 30-cm column oven from the column manager.