2 Engineering
2.4 Safety and switching
DB1 variable frequency drive
11/20 MN040031EN
Eaton.com
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2.4.4 Mains contactors
The mains contactor enables an operational switching on and off of the
supply voltage for the variable frequency drive and switching off in case of a
fault. The mains contactor is designed based on the mains-side input current
I
LN
of the DB1 variable frequency drive for utilization category AC-1
(IEC 60947) and the ambient air temperature at the location of use.
￫
While planning the project, please make sure that inching opera-
tion is not done via the mains contactor of the variable
frequency drive on frequency-controlled drives, but through a
controller input of the variable frequency drive.
The mains voltage on the DB1 variable frequency drive can be
switched on a maximum of once every 30 seconds (normal ope-
ration).
￫
For UL-compliant installation and during operation, the mains
side switching devices must allow for a 1.25 times higher input
current.
￫
For the rated mains contactors for DB1 variable frequency drives,
please refer to
