Trip Θ - DEMA 400 Series User Manual

transformer with current transformers 30 A / 5 A is requested. The primary rated current of
the transformer is calculated as 26.8 A and value of I
30 A. IΘ> adjustment range is (0.10 – 3.20) I
4.3.2.3.3 T
e
Warming represents the constant time and is given in minutes. Te value is an empirically
determined value which must be reported by device manufacturers. The value of Te is
determined by measuring the time taken for the device to warm up to 63% of the Trip
Θ(maximum heating) limit when the device is loaded with IΘ> = Ir current current. Te value
can be selected in the range of (1 – 200) minutes.
4.3.2.3.4 k
Tripping threshold is the coefficient of translation and unitless. The value is determined
according to the needs of user and can be selected in the range of (1.00 – 1.50). To examine
the effect of the coefficient k on the tripping time, please look to the IEC thermic formula
given above.
Trip Θ
4.3.2.3.5
Trip Θ shows Trip warm-up value in %. The value of Trip Θ is %100 as default value. At the
same time, the user can change the thermal protection characteristic by manually setting this
value in the range of 50% to 200%. When the heating reaches this value, the relay will give
the tripping command to prevent the device from overloading and heating. When the Trip Θ
warning is requested to be monitored remotely with ancillary devices, for example a horn to
emit an audible signal or a light signal to give a visual warning, "Trip Θ" is assigned to the
Programmable relay outputs and the auxiliary warning device is controlled by this output.
When the Trip Θ threshold is reached, the Trip Θ function will feed the assigned output
auxiliary device and ensure that the status can be monitored remotely
4.3.2.3.6 Alarm
Function control can be selected as Active or Passive. Thermal overload protection alarm is
activated in the Active state and disabled in the Passive state.
> is set 0.89In from the ratio of 26.8 A /
Θ
n
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