Specifications are subject to change without notice (25.06.99)
1
Level Sensors
Level control for solid, liquid or
granulated substances
Capacitive sensors, types VR and VRY
Max. and/or min. control of discharging
Factory-set sensitivity
8 A DPDT output relay
LED-indications: Power supply and relay ON
Product Description
Ordering Key
H 491 166 230
Level control relay for
capacitive sensors, types VR
and VRY. The relay can con-
trol one or two levels of dis-
charging.
Type
Output
Power supply
Type Selection
Connection
Output
Supply: 24 VAC
Supply: 115 VAC
Supply: 230 VAC
Screw DPDT
H 491 166 024
H 491 166 115
H 491 166 230
terminals
Input Specifications
Sensitivity
Depends on sensor type
and material
Sensor voltage
Max. 24 VDC
terminal 8 is negative
Sensor current
Activated
Min. 15 mA, max. 20 mA
Not activated
Max. <5 mA
Sensor short-circuit current
Max. 45 mA
Type H 491 (Discharging)
Amplifier, Capacitive
Supply Specifications
Power supply AC-types
Overvoltage cat. II (IEC 60664)
Rated operational voltage
through pin 2 & 10
230
230 VAC 15%
115
115 VAC 15%
024
24 VAC 15%
Rated insulation voltage
2.0 kVAC (rms)
Rated impulse withstand
voltage
4 kV (1.2/50 s) (line/neutral)
General Specifications
Indication for
Output ON
LED, red
Power supply
LED, green
Environment
Degree of protection
IP 20 B
Operating temperature
-20 to +50C (-4 to +122F)
Storage temperature
-50 to +85C (-58 to +185F)
Output Specifications
Output
DPDT relay
Rated insulation voltage
250 VAC (rms)
Contact ratings
(cont./elec.)
Mechanical life
5 x 10
7
operations
Electrical life
10
5
operations
Operating frequency
7200 operations/h
Connection
Screw terminals
For mounting on DIN-rail
2
Specifications are subject to change without notice (25.06.99)
Mode of Operation
Max. and/or min. control of
solid, liquid or granulated
substances, e.g. sand, grav-
el, sugar or chemicals.
Example 1: Discharging
The diagram shows the level
control connected as max.
and min. control i.e. registra-
tion of 2 levels. The relay
operates when the max. sen-
sor (terminal 5 and 8) is
immersed provided that the
min. sensor (terminal 6 and 8)
is immersed too. The relay
releases when min. sensor is
no longer immersed.
Example 2
The diagram shows the level
control connected as max. or
min. control i.e. registration of
one level. The relay operates
when sensor (terminals 6 and
8) is immersed.
Charging
By using the break contact
terminals 23 and 24 (27 and
28), the contact function is
activated when neither of the
sensors is in the liquid, and
not activated when both sen-
sors are in the liquid.
Note
In certain cases it is recom-
mended to use screened
cable between sensor and
amplifier, e.g. where the cable
is placed parallel to the load
cables. The screen is con-
nected to terminal 8.
Wiring Diagrams
Example 1
Example 2
H 491
Power supply
Max. sensor, term. 5-8 immersed
Min. sensor, term. 6-8 immersed
Relay on
Operation Diagrams
Example 1
Accessories
Sensors: Types VR and VRY
Power supply
Sensor, term. 5-8 immersed
Relay ON
Example 2
Power Supply
Power Supply
PDF 
ZIP