Datasheet

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JUMO GmbH & Co. KG
Delivery address: Mackenrodtstraße 14
36039 Fulda, Germany
Postal address: 36035 Fulda, Germany
Phone: [phone]
Fax: [phone]
E-mail: [e-mail]
Internet: www.jumo.net
JUMO Instrument Co. Ltd.
JUMO House
Temple Bank, Riverway
Harlow, Essex CM20 2DY, UK
Phone: [phone]
Fax: [phone]
E-mail: [e-mail]
Internet: www.jumo.co.uk
JUMO Process Control, Inc.
6733 Myers Road
East Syracuse, NY 13057, USA
Phone: [phone]
1-800-554-5866
Fax: [phone]
E-mail: [e-mail]
Internet: www.jumousa.com
Data Sheet 602021
V1.00/EN/00073206
Panel-mounted Thermostats, EM Series
with 1, 2, 3, or 4 single-pole snap-action switches
Approvals/approval marks (see "Technical data")
DGRL
97/23/EG
Brief description
Thermostats control and monitor thermal processes. The devices of the EM series are available
as temperature controllers TR, temperature monitors TW, temperature limiters TB, safety tem-
perature monitors STW (STB), and safety temperature limiters STB. In the event of a malfunc-
tion, the STB switches the monitored machine to a safe operating status.
Panel-mounted thermostats operate according to the fluid expansion principle – a microswitch
is used as an electrical switching element.
Special features
• Temperature controller TR and temperature monitor TW
• Safety temperature limiter STB
• Tested according to DIN EN 14597
• Pressure Equipment Directive 97/23/EC
Switching function
Temperature controller TR and temperature monitor TW
If the temperature on the temperature probe exceeds the setpoint value, the microswitch is ac-
tivated by the transmission mechanics and the electrical circuit is opened or closed. If the tem-
perature falls below the selected setpoint (by the amount of the switching differential), the
microswitch is reset to its initial position.
Restart lock for temperature limiter TB and
safety temperature limiter STB
If the temperature on the temperature probe exceeds the set limit value, the electrical circuit is
opened and the microswitch is mechanically locked.
The microswitch can be manually unlocked once the temperature has dropped by approx. 10 %
of the scale range (approx. 15 % with a limit value setting >+350 °C).
For limit values exceeding 120 °C, the limit value set in the STB must be secured against incor-
rect adjustment (e.g. by a seal).
Self-monitoring for the safety temperature limiter STB
and safety temperature monitor STW (STB)
If the measuring system is destroyed (i.e. if the expansion fluid leaks), the pressure in the dia-
phragm of the STB and STW (STB) drops and permanently opens the electrical circuit. Unlock-
ing is then no longer possible.
When the probe has cooled down to a temperature below approx. -20 °C, the electrical circuit is
also opened. However, it automatically closes again when the temperature rises above -10 °C.
Use of the safety temperature monitor STW as a safety temperature limiter STB
The circuitry used with the thermostat must comply with DIN EN 14597 and VDE 0631.