S M ART T EMP ER ATUR E MONITORI NG R EL AYS
STATUS
Approved
SECURITY LEVEL
Public
DOCUMENT ID.
2CDC112285M0201
REV.
B
LANG.
en
PAGE
18/42
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4.1.5.
Factory 5: Transformer supervision with PT100
This profile allows transformer supervision with three escalation steps. Thresh-
old 1 is set to 130 °C and starts ventilation for cooling. If the threshold is reached
relay 1 trips. A cyclic switching function is assigned to relay 1 to periodically
switch the relay once per week for 15 minutes to keep the fan from clogging.
Threshold 2 is a pre-warning at 140 °C and trips relay 2. Additionally to the
threshold configuration the sensor error signals are assigned to relay 2 as well.
Threshold 3 is for the switch off at 155 °C.
Relays 1 and 3 operate in open-circuit-principle, relay 2 in closed-circuit-principle.
Automatic reset is active for all relays.
The operating logic and the settings are displayed in the block diagram:
