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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

outputrelaysarepickedup.Todothis,

aresethastobemadeafterswitching

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

ConnectionforPt100sensors

as per EN 60751/IEC 60751

can be delivered with

measuring-range between

-200 and +700 °C

2-channel evaluation

Sensormonitoringforinterrup-

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.

ThelimittemperatureTcanbeset

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

ThedevicecabeusedincombinationwithsensorsPt100

(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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SIL

IEC 61508

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