FOGRod hanging down in wetwell
The Fogrod is extremely simple.. and Simple = Reliable.
The LIT is the electronic unit that works with the FOGRod. It gives you two ways to control the station.
First, it has 10 relay outputs – this is like 10 floats separated by 6″ or 9″ (or more). Just choose the relays you want to use for off, lead, lag and alarm. You can wire them into the same terminals in the panel that the floats were wired to.
Second, it has an analog output – this goes up in 1mA steps for each point on the FOGRod. You can control the station just as if you had a pressure transducer.
Note: you can also use this analog output if you have SCADA or telemetry for remote level.
The LIT also has a fault relay (and visual alarms) to tell you when the FOGRod needs cleaning. How do the FOGRod & LIT work?
The FOGRod works using conductivity. Fresh air is an insulator and water is a conductor. The FOGRod has 10 metal contacts down its length, each one internally connected to a core of 10-core cable. The control panel unit (called the LIT) puts 5v on each wire and looks for current flow to ground. When a metal contact is under water then current flows, and when it is above the water no current flows. So the water acts like a lightswitch and the LIT can determine the level in the wetwell.
Cleaning the FOGRod
The FOGRod hangs by its cable, from a mounting bracket that you install just under the lid. When it needs cleaning just pull it up through the wiper that is an integral part of the bracket.
The FOGRod has no moving parts, no electronics and no sensitive components – so we give it a 10-year warranty in wastewater. It is very tough and designed to be hung in the turbulent part of the wetwell near the inflow.
Always Stops the Pumps – running pumps dry costs lots of money. The FOGRod always stops the pumps because once the wastewater level drops below the bottom of the FOGRod there is no way for current to flow through the fresh air to the receding water level. It’s the laws of physics. Any failure mechanism will stop the pumps.
Always Starts the Pumps – the FOGRod has 10 independent level points, and each one acts as a backup to those below. Suppose you set contact 5 to be your lead start (you wire relay 5 from the LIT into your alternating relay), if contact 5 isn’t working for some reason then the lead pump won’t start. But when the level reaches contact 6 the LIT turns on relays 1-6. So your lead pump starts – just a little higher in the wetwell. And the LIT gives an alarm light and activates a fault relay.
Prevents Short Cycling even with the Worst Rags – the LIT detects multiple contacts going wet together – rags or grease problem – and activates a 3-minute timer to prevent the pumps short-cycling.
LIT installed in control panel, level relays used for control (top), analog connected to SCADA (bottom left) and FOGRod cable (bottom center)
Works in Grease – grease is an insulator so doesn’t this stop the FOGRod working? It’s surprising to everyone the first time they see this technology working in wastewater. The reason conductivity rods work in grease is it is almost always “broken up” as it adheres to the rod – especially if you install the FOGRod in its ideal position near the inflow, in the more turbulent part of the wetwell. The LIT gives you an alarm when it sees that the grease is causing measurement problems, and keeps operating as close as possible to the intended start and stop points for a long time after this.
We offer a FREE trial to any city, town, county or parish. Call us today: 406 545 3023.
Read more about the FOGRod benefits, or see how easy it is to install.