38 ACH550 Installation, Operation and Maintenance Manual
ACH550-UH
6. Install each filter frame to the bonnet on top 
of the cabinet.
• Carefully align the frame’s mounting 
hooks with the slots in the bonnet. (The 
hooks should be pointing down.)
• Press down at the top of the filter frame. 
(The filter frame slides down 
approximately 3/4 inch).
• Check all around the filter frame for a 
secure seal to the exhaust box. 
Capacitors
The drive intermediate circuit employs several electrolytic capacitors. Their life span 
is from 35,000
…90,000 hours depending on drive loading and ambient temperature. 
Capacitor life can be prolonged by lowering the ambient temperature. 
It is not possible to predict a capacitor failure. Capacitor failure is usually followed by 
a input power fuse failure or a fault trip. Contact ABB if capacitor failure is suspected. 
Replacements for frame size R5, R6 and R8 are available from ABB. Do not use 
other than ABB specified spare parts.
Control panel
Cleaning
Use a soft damp cloth to clean the control panel. Avoid harsh cleaners which could 
scratch the display window.
Battery
A battery is only used in Assistant control panels that have the clock function 
available and enabled. The battery keeps the clock operating in memory during 
power interruptions. 
The expected life for the battery is greater than ten years. To remove the battery, use 
a coin to rotate the battery holder on the back of the control panel. Replace the 
battery with type CR2032.
Note: The battery is NOT required for any control panel or drive function, except the 
clock.