Specifications are subject to change without notice (25.06.99) 1
Level Sensors
Amplifier, Conductive
Type H 496
• Level control for conductive liquids
• Max.- min. control of charging/discharging
• Selection of charging or discharging by inter-
connection of the terminals
• 3 sensitivity ranges, from 200 Ωto 220 kΩ,
selectable by switch in the front
• Adjustable sensitivity
• Possibility of parallel connection
• Level probe supply max. 6 Vpp, 1.5 mA, according
to IEC 60364-4-41, PELV/SELV
• Output: 8 A DPDT relay
• LED-indication for relay and power supply ON
• AC power supply
Product Description
Level control relay for conduc-
tive liquids which can control
two levels of charging or dis-
charging. The relay features
sensitivity ranges from 200 Ωto
220 kΩ(5 m Siemens to 4.5 µ
Siemens). If more than two le-
vels are required, more relays
can be coupled in parallel.
Ordering Key
Housing
Type/function
Output
Power supply
Type Selection
Output Supply: 24 VAC Supply:115 VAC Supply: 230 VAC
DPDT H 496 166 024 H 496 166 115 H 496 166 230
Input Specifications
Level probe supply 6 Vpp (IEC 60364-4-41,
PELV/SELV)
Level probe current
Range 1: 200 Ω- 2.2 kΩ1.5 mA
Range 2: 2.0 kΩ- 22 kΩ150 µA
Range 3: 20 kΩ- 220 kΩ15 µA
Clock in/clock out Clock in: terminal 2
Clock out: terminal 1
Approx. 100 Hz ±15 Hz
square wave
Duty cycle typically 60-40
For parallel coupling of
amplifiers
Always use screened cable
to avoid ambient noise
Screen must be connected
to terminal 8
Reaction time Approx. 1 s
Output Specifications
Output DPDT relay
Rated insulation voltage
250 VAC (rms) (cont./elect.)
Contact ratings (Ag-CdO)
(IEC 60947-5-1/IEC 60337)
Resistive loads AC 1 8 A/250 VAC (2000 VA)
DC 1 0.4 A/250 VDC (100 VA)
or 4 A/25 VDC (100 VA)
Small inductive loads AC 15
2.5 A/230 VAC
DC 13
5 A/24 VDC
Mechanical life ≥30 x 106operations
Electrical life AC 1 ≥2.5 x 105operations
(at max. load)
Operating frequency ≤7200 operations/h
Insulation voltages
Rated insulation voltage ≥2.0 kVAC (rms)
(cont./elect.)
Rated impulse withstand
voltage 4 kV (1.2/50 µs)
(cont./elect.) (IEC 60664)
H 496 166 230
2Specifications are subject to change without notice (25.06.99)
Supply Specifications General Specifications
Indication for
Power supply ON LED, green
Output ON LED, red
Environment
Degree of protection IP 20 B
Pollution degree 3 (IEC 60664)
Operating temperature -20 to +50°C (-4 to +122°F)
Storage temperature -50 to +85°C (-58 to +185°F)
Scale accuracy +/- 20%
Hysteresis 100% of set value
Weight 200 g
H 496
Mode of Operation
Max., min. control of char-
ging/discharging.
Example 1
The diagram shows the level
control connected as max.
and min. control, i.e. detection
of 2 levels. The relay operates
(out)/releases (in) when the
liquid reaches the max. elec-
trode (terminal 5), provided
that the min. electrode (termi-
nal 6) is in contact with the li-
quid.
The relay releases (out)/ope-
rates (in) when the min. elec-
trode is no longer in contact
with the liquid.
By use of a container of a
conductive material terminal 8
can be connected to the con-
tainer. If the container is made
of a non-conductive material,
an additional electrode is
needed, indicated by the dot-
ted line in the diagram. If only
one level is required, terminals
5 and 6 must be interconnect-
ed, to select either max. or
min. control.
Example 2
If more than 2 levels are
required, two or more ampli-
fires can be coupled in paral-
lel, as in example 2.
Pin 8 (clock out) and pin 9
(clock in) are connected to
synchronize the clock in all
systems - otherwise interfe-
rence may occur. This means
that one system determines
the clock for all systems cas-
caded.
The clock in/clock out con-
nection must be screened
cable. In some cases
screened cable must be used
to achieve perfect operation
e.g. in cable pits or trays
where the sensor cable is
placed in parallel with power
cables. The screen must be
connected to terminal 8.
Wiring Diagrams
Example 1 Example 2
Power supply Power supplyPower supply
Min.
Max.
Clock out Clock in
PE=Terminal 8 (where used)
1: Clock out
2: Clock in
3-4: Charge
3-4: Charge
Power supply
Overvoltage cat. III (IEC 60664)
Rated operational voltage
through term. 21 & 22 230
230 VAC ±15%,
50/60 Hz, -5/+5 Hz
115
115 VAC ±15%,
50/60 Hz, -5/+5 Hz
024
24 VAC ±15%,
50/60 Hz, -5/+5 Hz
Voltage interruption ≤40 ms
Rated insulation voltage ≥2.0 kVAC (rms)
Rated impulse withstand volt. 4 kV (1.2/50 µs) (line/neutral)
Rated operational power 2.5 VA
Specifications are subject to change without notice (25.06.99) 3
H 496
Accessories Settings
Conductive level probes:
VN..., VNI..., VNY..., VNYI...,
VT..., VTI..., VPP..., VPC...,
VH...
Left knob: Sensitivity.
Right knob: Range selection
Operation Diagram
Power supply
Max.
Min.
Relay (charging: in)
Relay (discharging: out)
