Should I add a backup low level alarm float?
No, we think it’s a bad choice, here’s why..
Generally, adding redundancy isn’t trouble free, as many people who have spent time trying to design redundant systems will testify. Often, redundancy can add complexity and create more opportunities to fail.
The low level float is in wastewater the whole time and even though it is sitting below the worst of the grease, it still has plenty of opportunities to get grease buildup – and if not, plenty of opportunities for other debris in the wetwell to get tangled up around it.
If you use the low level float only as a telemetry alarm (or for the red light on top of the panel) then you aren’t compromising the reliability of starting and stopping the pumps – and it’s not a bad choice, the downside is it might create some false alarms. But you can judge that over time and remove it with little consequence later.
If you use the low level float to stop the pumps then you might be compromising the reliability of starting and stopping the pumps – and it will probably be a bad choice.
One of the great features of the FOGRod is the reliability of the OFF signal. Once the water drops off the bottom of the rod there is no way for current to flow through fresh air to ground. The low voltage applied to each contact on the FOGRod has to jump through fresh air to the receding water level below. This means you will always get an OFF signal and you can always rely on your pumps stopping.
Even if the LIT fails (or power fails to the LIT) you will get an OFF signal because the level relays will all spring open. That’s why a low level float is unnecessary.