
Model: 2852-OWS User Manual Rev: 2.3
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1.0 INSTRUMENT OVERVIEW
The Arjay Oil/Water Separator & Sump Alarm provides a means for detecting the accumulation of
oil in oil/water separators, sumps, or similar vessels. The Arjay probe has an active capacitance
sensor at the probe tip that monitors the water at the depth of the active probe end. Water has a
high dielectric constant, which results in a high capacitance reading. Oil (or a similar hydrocarbon
or low dielectric liquid) separates to the surface of the water and eventually accumulates to a depth
that the oil/water interface crosses the active probe tip. The dielectric of the oil is substantially
lower than water, which results in a dramatic decrease in capacitance.
The remote mounted Arjay 2852 controller monitors the capacitance change of the probe and
activates a relay contact for use with alarms, pumps, valves, etc. The sensor requires at least 6
mm of oil to cross the active probe to indicate an alarm. Emulsified separations may require more
coverage of the probe tip to initiate an alarm. The active probe tip is made to 100mm to
accommodate for these emulsified interfaces.
The complete 2852-OWS system consists of the probe, the PMC card, and the 2852 controller.
The standard probe is constructed of a Teflon coated probe with SS inactive sheath. The PMC
card is mounted in a junction box safely above the water surge level. The PMC card translates the
capacitance signal from the sensor into a frequency pulse, which can then be transmitted up to one
kilometer to the 2852 controller via 2-wire shielded cable OR 3-wire shielded cable for A00764
probe.
The Oil/Water Separator must be of the type that is permanently filled with water. The clean water
is gradually displaced from the vessel as oily water is introduced. The active sensing tip of the
probe is positioned below the oil suction pipe and above the clean water discharge pipe. When the
oil/water interface reaches the probe tip, the alarm activates.
Sumps normally have a pump with the suction on the pit bottom. The liquid level of the sump is
maintained above the probe tip with a separate level device so that the probe tip is continuously in
liquid. If there is sufficient accumulation of oil that it risks suction by the pump, the alarm activates.
A dry probe tip condition in either application will indicate an alarm.
The model is intended for use in General Purpose non-hazardous areas. For hazardous location
use refer to Arjay Engineering Ltd. For appropriate model.
1.1 Features
Microprocessor based capacitance Controller
Relay and 4/20mA alarm output
Modbus protocol via RS-485 for access by Arjay handheld, Central Access Panel or
compatible system
Local Auto calibration or remote calibration via network
User specified custom features may be added by contacting Arjay Engineering Ltd.
1.2 Model Number vs. Voltage Input
2852-OWS-1 100-240 VAC power input
2852-OWS-3 12 VDC power input
2852-OWS-4 24 VDC power input