Fronius Symo Advanced 10.0-3-M Operating Instructions Manual page 49

IMPORTANT!Local regulations, the electricity retailer or other factors may re-
quire a residual-current protective device in the AC connection lead.
A type A residual-current circuit breaker with a trip current of at least 100 mA is
generally sufficient in this case. In particular cases, and depending on local
factors, however, the type A residual-current circuit breaker may trip at the
wrong time. For this reason, Fronius recommends that a residual-current circuit
breaker that is suitable for frequency converters should be used.
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