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2 Functions
96
7ST6 Manual
E50417-G1176-C251-A3
the ambient temperature sensing is assumed, and the last valid ambient temperature
is kept. In addition, the indication
„Fail.TEMPSENS“
(FNo. 158) is output.
If the ambient temperature sensing is already disturbed on power-up of the protection
relay, the ambient temperature set at address
4215
AMB.TEMP.
is used for the cal-
culation, and the indication
„Fail.TEMPSENS“
(FNo. 158) is output, too.
Figure 2-24
Ambient temperature sensing
The parameter
MIN TEMP PRESET
(address
4216
) is provided for line sections where
the temperature is higher than at the location of the ambient temperature sensing (e.g.
tunnels in winter: ambient temperature = -15
°
C, tunnel temperature = 8
°
C). In such a
case, a lower threshold must be set for the used ambient temperature (e.g.
MIN TEMP
PRESET
= 8
°
C).
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