Galvanic isolation via transformer (4 kV, 8 mm creepage
distance)
Isolation of contacts and electrodes from power supply
Operating temperature range (°C)
Storage temperature range (°C)
Weight (g)
0.85 →1.10 x Un
3 VA
250
Ω→1 MΩ
± 30 %
24 V AC (50/60 Hz)
1 mA (50/60 Hz)
10 nF
300 ms
500 ms
1 AgNi changeover relay 8 A AC max.
Class II
2.5 kV AC
-20 →+50 °C
-40 →+70 °C
150
Principles
Operating principle
General principle :
The ENRM monitors the levels of conductive liquids. The principle is based on measuring the apparent resistance of the liquid between two submerged probes. When this value is lower than the
preset threshold displayed on the unit's front panel, the relay changes state. To prevent any occurrences of electrolysis, an AC current is passed through the probes. A rotary switch on the front
panel can be used to select the desired function and sensitivity range. A level can be monitored using the 2
nd
rotary switch.
In this instance, the max. probe remains above the liquid and an adjustable time delay prevents the wave effect.
A green LED indicates that the supply voltage is present.
A yellow LED indicates the output relay's state.
When the green and yellow LEDs are flashing, this indicates an incompatible adjustment position.
Principles
Unless otherwise specified, the characteristics given are applicable to all or part of the product range selected
26/02/2014
www.crouzet.com
Monitoring a level, filling function, activation time
(level : 1 - on delay, function Up LS (Low Sensitivity : 250
Ω to
5 kΩ), Up St (Standard Sensitivity : 5 kΩ to 100 kΩ), Up HS (High Sensitivity : 50 kΩ to 1 MΩ).
When the level of liquid drops below the probe for a period exceeding the value of time delay T set on the front panel, the relay energises and remains on until the level of liquid reaches the probe
again.
If the level of liquid returns above the level set before the time delay elapses, the relay does not come on.
Note
When the power returns after a power break, the output relay only energises after time delay T if the level of liquid is below the threshold.
N
o
Legend
Level
Relay
Principles
Monitoring a level, emptying function, activation time
(level : 1 - on delay, function Dwn LS (Low Sensitivity : 250
Ω to
5 kΩ), Dwn St (Standard Sensitivity : 5 kΩ to 100 kΩ), Dwn HS (High Sensitivity : 50 kΩ to 1 MΩ).
When the level of liquid rises above the probe for a period exceeding the value of time delay T set on the front panel, the relay energises and remains on until the level of liquid drops back below the
probe.
If the level of liquid drops back below the level set before the time delay elapses the relay does not come on.
Note
When the power returns after a power break, the output relay only energises after delay time T if the level of liquid is above the threshold.
N
o
Legend
Level
Relay
Unless otherwise specified, the characteristics given are applicable to all or part of the product range selected
26/02/2014
Principles
www.crouzet.com
Monitoring a level, filling function, deactivation time
(level : 1 - off delay, function Up LS (Low Sensitivity : 250
Ω to
5 kΩ) or Up St (Standard Sensitivity : 5 kΩ to 100 kΩ) or Up HS (High Sensitivity : 50 kΩ to 1 MΩ).
When the liquid level drops below the probe the relay energises immediately and remains on until the level of liquid reaches the probe again and remains above it for a period exceeding time delay T
set on the front panel.
If the level of liquid drops back below the level set before the time delay elapses, the relay remains on.
Note
When the power returns after a power break, the output relay energises immediately if the liquid level is below the threshold.
N
o
Legend
Level
Relay
Principles
Monitoring a level, emptying function, deactivation time
(level : 1 - off delay, function Dwn LS (Low Sensitivity : 250
Ω to
5 kΩ) or Dwn St (Standard Sensitivity : 5 kΩ to 100 kΩ) or Dwn HS (High Sensitivity : 50 kΩ to 1 MΩ).
When the level of liquid rises above the probe the relay energises immediately and remains on until the level of liquid drops back below the probe for a period exceeding the value of time delay T set
on the front panel.
If the level of liquid returns above the level set before the time delay elapses the relay remains on.
Note
When the power returns after a power break, the output relay energises immediately if the level of liquid is above the threshold.
N
o
Legend
Level
Relay
Unless otherwise specified, the characteristics given are applicable to all or part of the product range selected
26/02/2014
Principles
www.crouzet.com
Monitoring two levels, emptying function
(level : 2, function Dwn LS (Low Sensitivity : 250
Ω to
5 kΩ), Dwn St (Standard Sensitivity : 5 kΩ to 100 kΩ), Dwn HS (High Sensitivity : 50 kΩ to 1 MΩ).
The output relay remains open as long as the level of liquid has not reached the maximum probe. Once the maximum level is reached the contact closes and the tank can then be emptied (valve
opened, pump started, etc). When the level drops below the minimum level the contact opens and interrupts the emptying process.
Note : when monitoring two levels the time delay preventing the wave effect is not in operation.
Note
When the power returns after a power break, the output relay energises immediately if the level of liquid is above the threshold.
N
o
Legend
Maximum level
Minimum level
Output relay : Down
Principles
Monitoring two levels, filling function
(level : 2, function Up LS (Low Sensitivity : 250
Ω to
5 kΩ) or Up St (Standard Sensitivity : 5 kΩ to 100 kΩ) or Up HS (High Sensitivity : 50 kΩ to 1 MΩ).
The output relay remains on as long as the level of liquid has not reached the maximum probe. As soon as the maximum level is reached the contact opens and pumping stops. When the level drops
below the minimum level the contact closes again and pumping restarts to bring the level of liquid back up.
Note : When monitoring the two levels the time delay preventing the wave effect is not in operation.
Note
When the power returns after a power break, the output relay energises immediately if the level of liquid is below the threshold.
N
o
Legend
Maximum level
Minimum level
Output relay : Up
Unless otherwise specified, the characteristics given are applicable to all or part of the product range selected
26/02/2014
Dimensions (mm)
ENRM
www.crouzet.com
Connections
Adjusting two levels
Monitoring filling "Up"
A1-A2 : power supply
N
o
Legend
Unless otherwise specified, the characteristics given are applicable to all or part of the product range selected
