ABB ACH400 Series Retrofit Manual page 2

ACH400 to ACH550
Drive Replacement Instructions
This guide takes a step by step approach to upgrading your HVAC Drive.
When it is time to replace your ACH400 NEMA 1 drive with the newer
ACH550 NEMA 1 drive, reusing the existing electronic bypass (e-by-
pass) can greatly increase the value to your company.
ABB offers this step by step guide to help you easily install an ACH550
drive while maintaining the existing bypass components.
The mounting and interconnection between the existing electronic by-
pass unit and the new drive are detailed with instructions and photos.
These instructions are written for qualified and competent electrical per-
sonnel with a familiarity of circuits up to 500V and AC drives. Only quali-
fied personnel should attempt these procedures.