Parameter:
Min Operate Time
•
Default setting:
0 s
With the parameter a minimum operate delay time can be selected. The operate delay time of
inverse‑time characteristic curve never falls below the minimum operate delay time.
[dw_7SR5_minimumoperatingtimecurve, 1, en_US]
Figure 5-25
Minimum Operating Time of the Curve
This is traditionally used with recloser systems only and otherwise is recommended to be left at the
default setting of 0 s.
Parameter:
Follower DTL
•
Default setting:
0 s
This setting allows an additional time to be added to that achieved by the selected characteristic curve. It
is applied as a DTL time after the operate state from the curve is achieved. With this setting, the whole
curve is shifted linearly on the time axis by this additional definite time.
This is traditionally used with recloser systems only and otherwise is recommended to be left at the
default setting of 0 s.
Parameter:
Reset
•
Default setting:
0 s
The
Reset
parameter is used to define whether the element pickup resets to 0 instantaneously when the
current falls below setting or a reset curve characteristic or fixed DTL is applied. This operation is signifi-
cant during intermittent faults where an induction disc device would be partially rotated when the fault
current is reapplied.
Parameter Value
Description
IEC/ANSI Decaying
This selection applies a resetting curve to the element pickup to provide emula-
tion of an induction disc device. The standard IEC curve is applied if the operating
Char
is an IEC characteristic and the ANSI reset curve is applied for an ANSI oper-
ating
Char
. Select this setting if the device is coordinated with electromechanical
devices or other devices which perform a disc emulation reset.
0 s
Use this setting for instantaneous reset of the element. When the current falls
below setting the pickup will instantaneously reset completely and subsequent
increase in current above setting will restart the operation delay from 0.
Protection and Automation Functions
5.15 51G Time-Delayed Earth Fault – Measured
250
Reyrolle 7SR5, Transformer Protection Device, Device Manual
C53000-G7040-C015-1, Edition 11.2019
