awc 2 optical level sensor redundancy

[george7523]

hi,

i have 2 optical level sensor setup for ato/awc. During auto water change, tank water would be drained past below the bottom sensor because it fails to recognize its dry state. This failure seem to happen around 1 year time to the bottom sensor. I suspect due to it being submerged all the time. I've had to replaced the bottom sensor about 3 times, each lasting about 1-2 year.

question:

1. would float sensor be more reliable to use as the bottom sensor ?

2. how can I use extra optical/float sensor for redundancy so that when the bottom sensor fails to recognize dry state and the water is drained past it, another sensor can stop the drain pump connected on the power bar ?

thank you

[vanessastaudt]

hi,

i have 2 optical level sensor setup for ato/awc. During auto water change, tank water would be drained past below the bottom sensor because it fails to recognize its dry state. This failure seem to happen around 1 year time to the bottom sensor. I suspect due to it being submerged all the time. I've had to replaced the bottom sensor about 3 times, each lasting about 1-2 year.

question:

1. would float sensor be more reliable to use as the bottom sensor ?

2. how can I use extra optical/float sensor for redundancy so that when the bottom sensor fails to recognize dry state and the water is drained past it, another sensor can stop the drain pump connected on the power bar ?

thank you

Yes.

1. Float sensor: Yes, I would use a float sensor as the bottom AWC sensor. Since your optical sensors repeatedly fail after long-term submersion, a float is a reasonable and potentially more reliable choice for the drain-stop sensor.
2. Redundancy: Use a third sensor slightly below the normal bottom sensor as an emergency cutoff. Configure it through Programmable Logic to turn OFF the drain-pump outlet if the water drops too far.