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ZIEHL industrie-elektronik, 74523 Schwäbisch Hall, Germany, +49 791 504-0, info@ziehl.de, www.ziehl.de
The safety temperature limiting de-
vice STR100 detects the resistance
of a Pt100-sensor connected to the
input. This is linearized and evalu-
ated in 2 separated channels. If the
measured temperature is smaller
than the limit value adjusted, both
output relays are picked up. To do this,
a reset has to be made after switching
on the supply voltage (close contact
between terminals 3+4). The relays
are wired in such a way to have the
function of a change-over switch to
the outside. The load circuit is only
closed when both relays are picked
up. If a malfunction occurs or if the
limit value is exceeded, both relays
are released and the load circuit is
separated. The released relays K1
and K2 are indicated by the lighting
up of the red LEDs. When the limit
value is exceeded, a third relay picks
up which is used for error indication.
Interruption of the sensor or short-
circuit are signaled by a red LED
each and also lead to disconnection
of both channels.
Only when the temperature has
fallen below the response value by
the switching hysteresis of about
10°C and no malfunction occurs, it
is possible for the STR 100 to close
the load circuit after actuating the
reset key.
Readiness for switching on is
displayed by the third relay and
a LED. An incorporated safety
fuse avoids welding of the relay
contacts.
Safety temperature limiting
device meets safety category
3 (SK 3) as per DIN EN 954-1
SIL2 according to IEC61508
Connection for Pt 100 sensors
as per EN 60751/IEC 60751
can be delivered with
measuring-range between
-200 and +700 °C
2-channel evaluation
Sensor monitoring for interrup-
tion and short-circuit
LED-displays for relay posi-
tion, error messages and
readyness for switching on
Relay for message readiness
for switching on
Setting of limit value to be
sealed
Incorporated reset key
Connection for external reset
key
Assembly-friendly plug-in
base housing S 12
1
Safety Temperature-Limiting-Device
Description
Safety Temperature-Limiting-Device STR100
for Pt100
The electrical safety temperature
limiting device type STR100, in
connection with Pt100 sensors,
monitors temperatures in ap-
plications for which monitoring
with increased safety is required.
Functioning corresponds to type
2BDK as per VDE 0631.
The limit temperature T can be set
at the front by means of a scaled
potentiometer. An unauthorized
or unintended manipulation of
the limit is prevented by a trans-
parent plastic-plate which can
be sealed.A potential free relay
contact is switched off when
exceeding the limit value.
Safety temperature limiting devices are used in plants
when temperature monitoring has to meet high require-
ments:
• Industrial furnace plants
• Dyeing machines
• Thermal oil plants
The device ca be used in combination with sensors Pt100
(RTD). The suitability must be proved in combination
with the used sensors. Regular checks are stipulated
for enhanced safety requirements.
The safe STR100 can be used in applications, in which
an increased safety level up to SIL 2, PL c is required.
It meets the requirements of safety category 3 (Safety
of machines according to DIN EN 954-1, for models
with supply-voltage DC 24 V and AC 230 V tested
and approved by TÜV Rheinland with reports T24/00,
19.6.2000, T103/2007, 25.1.2007 and Z103/2007 E2,
12.9.07. Reports see homepage www.ziehl.de).
2017-03-24
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Part numbers:
T224148 0...200 °C AC 230 V
T224142 100...300 °C AC 230 V
T224144 200...500 °C AC 230 V
T224058 0...200 °C DC 24 V
T224059 100...300 °C DC 24 V
T224062 200...500 °C DC 24 V
Other measuring ranges upon request
STR100
