Combo Single-Level / Hydrocarbon Liquid 
Sump Sensor 
OPW P/N: 30-3224 
 
Combo Single-Level/Hydrocarbon Liquid Sump Sensor 
This sensor is made from the Hydrocarbon Liquid Sump Sensor (30-
3219-12) with an Interstitial Level Sensor (30-3221-1A) clipped to its 
side. The combination sensor is designed to detect the presence of 
liquid hydrocarbons and water in sumps, dispenser pans and other 
locations where the presence of a liquid could indicate that a leak has 
occurred. 
The  sensor  contains  a  carbon/polymer  material  that  changes 
resistance when exposed to liquid hydrocarbons. The level sensor 
portion  simply  clips  onto  the  hydrocarbon  sensor  and  can  be 
positioned at any desired height to activate in the presence of liquid. 
This sensor can be used to monitor wet wells to ensure that a liquid 
is normally present. In the event of a break in the cable, the system 
will activate the alarm. 
 
 
 
 
 
*NOTE: Maximum Wiring Length is the maximum length of cable to 
be used to connect all sensors on an individual channel. This length 
includes run of cable from I.S. Barrier to each sensor board in the 
string. 
 
Channel 1: Red = Power, Black = Signal 
Channel 2: White = Signal