Implementing A Bypass Connection; Protecting The Contacts Of Relay Outputs - ABB ACS580-07 Hardware Manual

Implementing a bypass connection

If bypassing is required, employ mechanically or electrically interlocked contactors between
the motor and the drive and between the motor and the power line. Make sure with
interlocking that the contactors cannot be closed simultaneously. The installation must be
clearly marked as defined in IEC/EN 61800-5-1, subclause 6.5.3, for example, "THIS
MACHINE STARTS AUTOMATICALLY".
WARNING!
Never connect the drive output to the electrical power network. The connection
can damage the drive.

Protecting the contacts of relay outputs

Inductive loads (relays, contactors, motors) cause voltage transients when switched off.
ABB highly recommends to equip inductive loads with noise attenuating circuits (varistors,
RC filters [AC] or diodes [DC]) in order to minimize the EMC emission at switch-off. If not
suppressed, the disturbances can connect capacitively or inductively to other conductors
in the control cable and form a risk of malfunction in other parts of the system.
Install the protective component as close to the inductive load as possible. Do not install
protective components at the relay outputs.
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230 V AC
230 V AC
+ 24 V DC
1) Relay outputs; 2) Varistor; 3) RC filter; 4) diode
Guidelines for planning the electrical installation 69
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