Series 16M Inverse Mode Bench Test

The below instructions help describe how to bench test a Series 16M conductivity relay in Inverse mode.  This will help users ensure the relay is working properly and help explain the operation and wiring of the board. 

The relay works off liquids natural conductive properties and is typically wired to conductivity probes.  However, all Warrick conductivity relays also work with dry contact switches, like a LS-800 float level switch.  This also allows users to place jumpers between the sensor contacts to help test the board.

Single Level Service High Alarm 

Below diagram explains how to test the board if using it as a high-level alarm.  Typically, Inverse mode is used for low-level alarms, but Inverse mode can still be used for high-level, the LED will just be on opposite of the alarm and you will need to use the Normally Closed (NC) contact.

Place a jumper between H (High) and G (Reference) contacts.  This will simulate that the H and G probes are in the liquid and the relay will be deenergized (LED off).  Remember Inverse mode the relay is energized when the probe contacts are dry.  The Normally Open (NO) contact will open, and you will have no continuity between NO and Common (C).  It will be closed between NC and C.     

Next step is to remove the jumper between H and G.  This will simulate that all probes (H, L, and G) are not in the liquid.  The relay will be energized, and you should have continuity between NO and C, and no continuity between NC and C.  

Single Level Service Low Alarm

The diagram below explains how to test the board if using it as a low-level alarm.  Place a jumper between H and G contacts, which will simulate the probes are in the liquid.  Remember, even though this is a low-level alarm, you still use H and G as the probe contacts.  The relay will be deenergized (LED off), and thus the Normally Open (NO) contact will open, and you will have no continuity between NO and Common (C).  It will be closed between NC and C.

Next step is to remove the jumper between H and G, which will simulate that all the probes are dry.  The relay will be energized, and the LED will be on.  You should then have continuity between NO and C. 

Differential Level Service (Pump or Valve Control)

Inverse mode differential service is used to fill or pump a tank up.  First step is to remove all jumpers which will simulate that all both probes are not in the liquid.  The relay will be energized (LED on), and the Normally Open (NO) contact will close.  You should have continuity between Common (C) and Normally Open (NO).     

Next step is to place a jumper between L and G.  This will simulate that the liquid level is rising, which is typical in a pump up (valve fill) situation.  However, the relay should remain energized because it is latched until the liquid level reaches the high probe, and still have continuity between C and NO.

Last step is to add a jumper between H and G, and keep the jumper between L and G.  This will simulate that all the probes are in the liquid.  The relay should now be deenergized (LED off) and the Normally Open (NO) will be open and the Normally Closed (NC) will be closed. 

Additional Tests to Run

After the relay is bench tested, you can also perform these same tests at the probe fitting.  This will ensure the wiring is correct and there are no shorts present.  You may need a helper to confirm the relay is actuating.    

Since jumping the relay out does not test the relay's ability to conduct through a liquid, you can also perform these same tests using a bucket of water.  When it calls for two contacts to be jumped out, for example H and G, then both H and G probes should be placed in the bucket of water.  This will accomplish the same thing and test the relay's ability to conduct through the liquid. 

You may also choose to leave the probes installed and place the probe wire directly into the bucket of water.  In this case the wire will act as the probe and the probe wire.