Operating Principle - Eaton EMR4 Serie Instrucciones De Servicio Y De Montaje

II Functions diagrams
Maximum filling level
Minimum filling level
Reference electrode C
Control supply voltage
Relay contact emptying
Relay contact filling
Function ON-delay
Function OFF-delay
These liquid level relays can also be
The products EMR4-N100-1-B and EMR5-N80-1-B can be
cascaded, i.e. it is possible to interconnect all electrodes as
required.
Relay AL1 Contact closed
Relay AL2 Contact closed
Relay AL1 Contact open
Relay AL2 Contact open
Relay AL1 + AL2 Contact closed
NOTICE EMR4-N500 (C):
In case of use in low resistive conducting liquids asymmetries
may occur causing a DC voltage offset of several mV. For
further technical information, see our catalog.
Emergency On Call Service: Local representative (http://www.eaton.com/moeller/aftersales) or +49 (0) 180 5 223822 (de,en)
operated with 2 electrodes C and MAX
only. In this case the output relay will be
energized/de-energize around the filling
level MAX.
LEDs
OFF Alarm electrode not wetted
OFF Alarm electrode wetted
ON Alarm electrode wetted
ON Alarm electrode not wetted
OFF Failure of control supply voltage

Operating principle

These relays monitor the filling levels of conductive liquids. The
measuring principle is based on a change in resistance recorded
by one-pole electrodes. Electrodes are connected to C, MIN, MAX.
When starting up, set the potentiometer "sens." to the minimum
value. EMR4-N500 (C) set "time value" at minimum, select delay
on operate function. Select suitable resistance range (sector).
Preselection of the response sensitivity in the range of 5 k:, 50
k:, and 500 k: is done by the preselection switch "sens.-sector".
The set value corresponds to the maximum range value.
Fine adjustment of the response sensitivity is done by the setting
potentiometer "sens." (sensitivity). To do this, the following scale
conversion factors referring to the range selection "sens.- sector"
have to be applied: 5 k: x 0.1, 50 k: x 1 and 500 k: x 10.
With EMR4-N100-1-B (B) select function DOWN.
After wetting electrodes C and MAX turn sensitivity potentiometer
"sens." towards the maximum value until the relay energizes.The
relay de-energizes as soon as the electrodes MAX and MIN are
no longer wetted.
Only EMR4-N500 (C): the maximum electrode level MAX is
exceeded by ON-delay A Ta 0.1-10 s. Taking the level beyond
the electrode IN is achieved by OFF-delay B Tr 0.1-10 s.
Only EMR4-N100-1-B (B): The function filling and emptying
control of tanks is selected by function UP (filling) and DOWN
(emptying) After a failure of the control supply voltage and at a
filling level between the level electrodes MAX and MIN the tank
will be filled. That means at selected function "DOWN" the output
remains de-energized and at the selected function "UP" the output
relay energizes at return of the control supply voltage.
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