10/13 MN03402007Z-DE/EN
Phase failure
ZEB overload relays are phase-loss sensitive.
In the event of a phase loss, i.e. a phase imbalance f 50 %
causes a trip of 10 seconds ±2 %.
h
If a ZEB relay is to monitor an AC motor, the current must
be fed on all three poles in order to prevent early tripping.
DC motors cannot be monitored.
DANGER
The device settings of the ZEB allows a deactivation of the
phase lost sensitivity (a Section "Device settings",
page 48 ).
When using the ZEB overload relay to protect motor in
potentially explosive environment, do not deactivate the
phase lost sensitivity to avoid a potential motor overhea-
ting.
Tripping characteristics
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