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Discussion Starter · #1 ·
I was racking my Brian the ofter day trying to figure out setup for silence and rest for alarm for low water and low polymer flow sensors any thoughts I was thinking I'm going to have to get some type of alarm relay or so thanks
 

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Donuts > Fried Eggs
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When low water is detected, it unseals a NC normally-energized "alarm" relay, causing the alarm to active. A "silence" button will open a NC de-energized relay in the horn circuit. A "reset" button will re-energize the "alarm" relay, putting the system back in normal.

Two $5 ice-cube relays and two push buttons. Done.
 

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Bilge Rat
motors and controls.........
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8,858 Posts
When low water is detected, it unseals a NC normally-energized "alarm" relay, causing the alarm to active. A "silence" button will open a NC de-energized relay in the horn circuit. A "reset" button will re-energize the "alarm" relay, putting the system back in normal.

Two $5 ice-cube relays and two push buttons. Done.
This will work if a manual reset is needed.

In reset is to be automatic, you'll need a NO reset pushbutton and a relay with one form C (double throw) contact.

Connect the low water switch leg (hot on low water, not hot on normal water) to one side of the reset button and the common of the relay contact. The NC relay contact goes to the alarm horn. The NO side of the relay contact goes to the other side of the reset button and one side of the relay coil. The other side of the coil goes to neutral.

When low water is detected, the alarm will sound through the NC relay contact. When the reset button in pushed, the relay coil is energized and latched by the NO contact. The NC contact is now open and the alarm is de-energized. When the water level returns to normal, the circuit is de-energized, the relay NO contact unlatches and the NC relay contact closes, but there's no power to sound the alarm.

Until the next time the water level is high.
 

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animal lover /rat bastard
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personally, I would use a time-delay relay for the manual silence, so that a careless operator, or shift change, doesn't cause an operator error in which the alarm is silenced for longer than a set time period ( I also feel that all plant operations should be thoroughly thought out for every possible point of failure - ie. the sequencing should be verified and approved by plant engineers prior to installation)
 

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Discussion Starter · #9 ·
I ended up installing a timer for the silence works great I ran into issue timer only has 1 contact and I'm having to install 2 flow switches but now I got to figure out how to make sure both alarm lights don't come on at the same time when get low flow on one or other being they make are tied together to make a horn and light go off when low flow trying figure it out with out adding another timer and ideas guys thanks
 
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