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BETA Monitoring
Monitoring of Plants and Devices
5
TT3 435 level relays
14/15
Siemens ET B1 · 10/2008
14
■
Overview
Level relays are used for the monitoring and control of conductive,
non-combustible liquids and powders. They ensure overflow
and dry run protection. Due to their sensor performance, the
devices can also be used for general resistance monitoring.
LED displays:
-
Green LED: lights up when operational voltage is applied
-
Yellow LED: lights up if MIN output relay is activated
-
Red LED: lights up if MAX output relay is activated.
■
Benefits
The measuring range up to 450 k enables a differentiation
between foam and liquid. It also increases the universal
application for resistance measurements.
Due to its low-frequency, electrically isolated measuring circuit,
the device has a high immunity to interference against system
coupling, which enables cable lengths of up to 1500 m and
suppresses the effects of electrolysis in the liquid.
•
The two outputs for minimum and maximum control can also
be used for the advance warning and tripping of limit values.
• 3
electrode connections for 1-step and 2-step level control
•
All standard products can be used as electrodes
•
High immunity to interference of the measuring circuit isolated
from the system
•
Programmable for open-circuit principle (with bridge X2 COM)
or closed-circuit principle (without jumper)
•
Separately adjustable delay times for t
v min
and t
v max
, 0.2
to 2 s
■
Technical specifications
5
TT3 435
Standards
IEC 60255; DIN VDE 0435-110
Supply
•
Rated control voltage U
c
V AC 230
-
Operating range
× U
c
0.8 ... 1.1
•
Rated frequency f
n
Hz
50/60
Setting range of the liquid level
k
2 ... 450
Switching point hysteresis of set value
-
At 450 k
% 3
-
At 2 k
% 6
Voltage temperature influence
From set value
%
< 2
Max. cable length to the
Set value k
electrodes at 100 F/km
450
m
50
100
m
200
35
m
500
10
m 1500
5
m 3000
Electrode voltage
Max.
V AC Approx. 10
Electrode current
Max.
mA AC Approx. 1.5
Response delay
Adjustable
s
0.2 ... 20
OFF-delay
Adjustable
s
0.2 ... 20
Rated operational voltage U
e
V
250
Rated operational current
I
e
A
5
Test voltage
Input/auxiliary circuit
kV
4
Input/output circuit
kV
4
Auxiliary/output circuit
kV
4
Terminals
•
Terminals
±
screw (Pozidriv)
PZ 2
•
Conductor cross-sections
-
Rigid
Max.
mm
2
2
× 2.5
-
Flexible, with end sleeve
Min.
mm
2
1
× 0.5
Permissible ambient temperature
°C
-20 ...
+60
Resistance to climate
Acc. to EN 60068-1
20/60/4
© Siemens AG 2008