My ABB ACS850-04-014A-5 has fault code 27, I can't reset it. Please let me know how can resolve it. Thanks!
you have already seen my previous answer to a similar question.
Normally changing the JCU-01 card is sufficient to solve the problem, at least as far as my experience is concerned.
However, it is possible that your drive may have some other fault, for example on the power unit - in the communication section to the JCU-01.
In this case only a careful examination could provide some clues, but here in the forum one can only make assumptions.
I therefore suggest that you contact the ABB service closest to you to ask for an evaluation of your fault, without excluding that due to the costs, it may not be the cheapest solution.
Hope this help you