water bug question

[pgordon]

I have a ductless unit on a compute room wall, the owners would like a water sensor in case the condensate pipe becomes cloged. The typical water bug (wb-200) will not detect distilled water nor de-ionized water, Is the water that is extracted from the air distilled or de-ionized ? I want to tie this sensor into a 12 volt security panel form 24 hour monitoring, A typical sensor for a pan installation that shuts down the unit will not work because they are 24V, and i am not even sure the ductless unit has constant power in side.
Please advise, Thanks

 

[petersonra]

I have a ductless unit on a compute room wall, the owners would like a water sensor in case the condensate pipe becomes cloged. The typical water bug (wb-200) will not detect distilled water nor de-ionized water, Is the water that is extracted from the air distilled or de-ionized ? I want to tie this sensor into a 12 volt security panel form 24 hour monitoring, A typical sensor for a pan installation that shuts down the unit will not work because they are 24V, and i am not even sure the ductless unit has constant power in side.
Please advise, Thanks

Its pretty close to being distilled but one would think there is enough CO2 in the water that it would be detected.

 

[jbelectric777]

if not maybe some kind of float switch, another way is to utilize the units 24v to a control relay )(pcb relay even) connect the alarm 12vdc to normally open contacts to send the signal to the alarm panel when the system shuts down, the contacts will drop out and close.....

 

[jbelectric777]

sorry i meant hook em up to the normally closed contacts in the c relay

 

[mcclary's electrical]

if not maybe some kind of float switch, another way is to utilize the units 24v to a control relay )(pcb relay even) connect the alarm 12vdc to normally open contacts to send the signal to the alarm panel when the system shuts down, the contacts will drop out and close.....

this is how I would handle it . Theymake float switches that plumb right into the drain line with a set of dry contacts.

 

[charlietuna]

Look up an outfit called Sensatrol -- buy the entire system to monitor whatever you want with a monitor who will call you or an alternate number.

 

[gar]

100608-1957 EST

To somewhat answer the original question on water conductivity.

Distilled water exposed to air always has some dissolved CO2 and this lowers its resistivity to a detectable level. With a standard test probe that has two plates about 1 sq-cm each and a spacing of maybe 2 mm and AC excitation at 1000 Hz I read about 100,000 ohms. Note there is also a capacitive component different than air. Generally deionized water from the grocery store is not this good. Nor is any distilled water exposed to air. Your condensate won't have any higher resistance. You do want to use AC excitation and 60 Hz is fine. If you find a suitable detector, then test your probe and detector device with grocery store water that is labeled distilled. Kroger has such and so does Absopure. Some water bottlers claim their their water is distilled when it is not.

When I have taken a sample of snow and melted it and checked its conductivity it was much more conductive than distilled water. I suspect the same for rain water.

Many years ago I developed an AC solid state liquid level control for the Charles F. Warrick Co. and it could easily work with a 1 megohm setpoint. The company was bought out by another company 20 or 30 years ago and my product may not exist any more. You do not want a DC type detector. This also might be too expensive for your application.

The float might be a better solution if you can work with a moderate level of water.

.

 

[stevenj76]

A waterbug has the floor sensor, and the box that has the circuitry.

An alarm point should go to the DDC system. Shutting down server room A/C to a crac unit would be unwise.

 

[charlietuna]

there are different types of water sensors -- those that sense continuity and others that expand when wet !