Reset After Triggering; Zero-Voltage Safety - Eaton EMT62 Manual

1.3.4 Reset after triggering

1.3.5 Zero-voltage safety

1 EMT6 Thermistor Overload Relays for Machine Protection
An error message of the standard EMT6 devices is automatically reset after
the equipment (motor winding) temperature has dropped to a sufficiently low
level. The operating mode of the EMT6-DB, EMT62-DB, EMT6-KDB and
EMT6-DBK variants can be set to "Automatic" or "Manual reset" using the
selector switch.
In automatic mode, the devices are reset automatically as described above.
In manual mode, they are reset after the motor has cooled down.
The EMT6-DB, EMT62-DB, EMT6-KDB and EMT6-DBK devices have an
additional option of connecting a button as a remote reset for manual mode.
DANGER

To ensure explosion-proof operation, it is permitted only to
reset/switch on the motor manually after it has cooled down,
or to switch it on automatically via a control interlock circuit
for the motor or electrical machinery.
Resets may be carried out manually at the installation or by
trained personnel in the control room.
Zero-voltage protection means that the error message is retained even after
loss of the supply voltage. Zero-voltage protection can be enabled or disabled
on the EMT6-DBK device. If the equipment has not yet cooled down
sufficiently after power is returned, the relays without zero-voltage
protection will also be tripped again. The message of devices without zero-
voltage protection will be lost only if power is returned after the equipment
has cooled down during an extended period of power loss.
DANGER

Particularly in Ex e applications, an automatic restart must be
prevented after an interruption of the control voltage. This is
prevented safely by means of the latching function of the power
relay (￫ Figure 3, page 46).
￫
Zero-voltage safety can be disabled at the EMT6-DBK device by
means of a wire jumper between terminals Y1-Y4.
EMT6 10/16 MN03407006Z-DE/EN www.eaton.com
1.3 Description of device
41