3UG4622-1AW30 Datasheet, PDF (87/114 Pages) List of Unclassifed Manufacturers – Monitoring and Control Devices

Monitoring Relays
3RS10, 3RS11 Temperature Monitoring Relays
■ Overview
The 3RS10 and 3RS11 temperature monitoring relays can be
used for measuring temperatures in solid, liquid and gas media.
The temperature is sensed by the sensor in the medium,
evaluated by the device and monitored for overshoot or
undershoot or for staying within an operating range (window
function).
The range comprises adjustable analog units with one or two
threshold values, digital units to DIN 3440, which are also a good
alternative to temperature controls for the low-end range, and
digital units for up to 3 sensors which have been optimized for
monitoring large motors.
Temperature
setting
LED "Device on voltage"
LED "Relay switched"
Hysteresis switch
General data
LED for display
"Up and Down" keys
Rotary switch for
parameter selection
NSB0_01421
■ Design
The temperature monitoring relays comply with:
• IEC 60721-3-3 "Environmental conditions"
• IEC 60947-5-1; VDE 0660 "Low-voltage controlgear,
switchgear and systems – Electromechanical controlgear"
• EN 61000-6-4 "Basic technical standard for emitted
interference (Industry)"
• EN 61000-6-2 "Basic technical standard for interference
immunity (Industry)"
• EN 50042 "Designations for terminals"
• UL/CSA
• DIN 3440 (3RS10 40, 3RS11 40, 3RS10 42, 3RS11 42).
Connection of resistance-type thermometers
2-wire measurement
When 2-wire temperature sensors are used, the resistances of
the sensor and wiring are added. The resulting systematic error
must be taken into account when the signal evaluator is
calibrated. A jumper must be clamped between terminals T2
and T3 for this purpose.
I
PT 100
T3
T2
T1
NSB01323a
Wiring errors
The errors that are generated by the wiring comprise
approximately 2.5 K/W. If the resistance of the wiring is not known
and cannot be measured, the wiring errors can also be
estimated using the following table.
Temperature drift depending on the length and cross-section of
the leads with PT100 sensors and an ambient temperature of
20 °C, in K:
Cable length Cross-section
m
mm²
0.5
0.75
1
1.5
0
0.0
0.0
0.0
0.0
10
1.8
1.2
0.9
0.6
25
4.5
3.0
2.3
1.5
50
9.0
6.0
4.5
3.0
75
13.6
9.0
6.8
4.5
100
18.1
12.1
9.0
6.0
200
36.3
24.2
18.1
12.1
500
91.6
60.8
45.5
30.2
3-wire measurement
To minimize the effects of the line resistances, a three-wire circuit
is often used. Using the additional wire, two measuring circuits
can be formed of which one is used as a reference. The signal
evaluator can then automatically calculate the line resistance
and take it into account.
I
T3
T2
PT 100
T1
I
NSB01324a
Siemens LV 1 T · 2006
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