Fault codes covered
88-41, 88-81
Code 88-81 MOSFET Open Malfunction (27VPA9 Only)
The MOSFET is an internal VFD component. Code 88-41 means the VFD detected a possible problem with the MOSFET and attempts to restart. Four code 88-41 errors in an hour generates a code 88-81 malfunction and a 2 hour lockout. Inspect wire harnesses and terminals for pinched wires or insulation that has bare spots. If no problems are found and the code persists the VFD must be replaced.
Source: ACHPVSR454-02SM troubleshooting pages.