I/O Linc with a Septic Sump-Guard?

[Brian H]

My tests on early I/OLincs showed a one volt sensor to ground was just where it started to trigger On even though the Green LED will glow if the sensor  voltage is being pulled down to a higher level than the trigger point.

Around 800 Ohms pulled it down to where it just started to trigger On.

2.25 volts is not low enough.

Would be hard to pick a resistor in parallel. Maybe a good point to start would be 10K or 4.7K.

[larryllix]

If you used 800 ohms to pull it down to 1v and the supply is 5v then the pullup current is E/R = 1v / 800 = 1.25mA

 

Assuming the pullup source is not a constant current and is just a resistor  E/I  = 4v / 1.25mA  =  3.2k ohms.

 

Now with your sensor in series with the calculated pullup resistor with we have 2.25v therefore the current in the circuit is

   E / R = (5-2.25)v / 3200 ohms = 0.859mA and your sensor is running at 2.25v / 0.859mA = 2618 ohms

 

To make this sensor pull the voltage down to 0.7 volts we require a circuit with  a resistance ratio of 0.7 / 5.0v  

 To get this the current in the pullup (3200 ohm) would be  E/R = (5-0.7)v / 3200 = 1.344mA

  and the resistance of the sensor in parallel with a resistor would be E/I = 0.7v / 1.344mA = 521 ohms

 

Since we have a sensor with (calc) 2618 ohms we need a parallel resistor of  1/Rp = 1/Rt - 1/Rs = 1/521 - 1/2618 = 1/650

Our parallel resistor would have to be 650 ohms.

 

 

Checking our sensor 'Off' voltage and assuming infinity resistance when dark we have a voltage divider using the 3200 ohm pullup and only the 650 ohm parallel resistance we would have a voltage of  5v x 650 / (3200 + 650) ohm = 0.844 volts. = not enough to switch the I/O Link .

 

A parallel resistance isn't going to work! Need a transistor or a phototransistor with a better curve.

 

 

E and O.E

[Brian H]

Its more complicated.

There is a pull up resistor from five volts to the Sensor Input connector. Also the Sensor LED with its own current limiting resistor is also from five volts to the Sensor Input. That is why the Sensor LED can glow from a resistance not low enough to trigger the Sensor On.

[paulbates]

Its more complicated.

There is a pull up resistor from five volts to the Sensor Input connector. Also the Sensor LED with its own current limiting resistor is also from five volts to the Sensor Input. That is why the Sensor LED can glow from a resistance not low enough to trigger the Sensor On.

 

Ironically the X10 PSC01 did/does a better job sensing for me than the IOlinc. I had several sensors connected to PSC01s in my x10 days that made contact just fine. On the iolinc, I got the glow. I'm not handy enough with electronics and eventually gave up. 

[larryllix]

Its more complicated.

There is a pull up resistor from five volts to the Sensor Input connector. Also the Sensor LED with its own current limiting resistor is also from five volts to the Sensor Input. That is why the Sensor LED can glow from a resistance not low enough to trigger the Sensor On.

If you referring to  my calculations the pullup resistor was calculated to be 3200 ohms and used to calculate that as parallel resistor isn't going to work.

 

A parallel resistor can pull the input down to 0.7 volts but the sensor becomes so insignificant in the circuit that the voltage can never return high enough to switch to he logic high state again with sensor at infinity ohms.

[Brian H]

I missed that point.

Does look like a parallel resistor is not going to cut it.

[jerlands]

Why not come directly off the float switch connecting a relay in series and feed that to an IOLinc?

 

Jon..

[GDavis01]

Not really understanding the complexities of why the photocell I have been trying will not work with a parallel resistor... I do get the point that it won't work. As I see it, simplistically, the warning light is not bright enough to bring down the voltage to a level below 1VDC which is where the IO Linc  is triggered. I would assume that I might eventually find a photocell that could handle the level of light coming from the warning light on the sump-guard but it might require a lot of hit-and-miss to find the right one!! It is unfortunate because it did seem like a simple solution.

 

So I am now considering the suggestion from Stu... the Micro Module. Am I correct that the correct model is the INSTEON 2443-222 MICRO ON/OFF MODULE?

 

To help with the reply I am attaching 2 pictures... the Outside and the Inside wiring of the sump-guard box

 

{You will note that there is a wire with an orange wire nut, on the right side of the Inside picture. When I opened the box, I thought that the power was off (didn't realize that there was a separate dedicated power line coming straight into the box!). Unfortunately the power wire to the TEST switch was loose and fried the switch!}

 

Not being familiar with the Micro module I would appreciate suggestions on how I would connect the device within the box.

 

[Brian H]

You can't find a resister value that allows the Sensor Voltage to go low enough to trigger it on. While allowing it to go high enough when the light is off to trigger back off.

[stusviews]

The Micro Module needs line and neutral. One side of the warning light should connect to neutral, does it (it's difficult to tell from the image as all wires are black)? If so, then connect the other side of the warning light to the yellow (#1) sense wire of the Micro Module. Cap (tape) the purple (#2) sense wire.

 

Link the Micro Module as a scene controller of any Insteon responder. It doesn't matter if you use an On/Off or dimmer Micro Module as it won't be connected to a load.

 

BTW, the TEST switch is a standard SPST panel slide switch, so it'll be easy to find. You'll have to drill out the rivets and secure the switch with screws and nuts.

[GDavis01]

Brian... I assume that you mean a resistor for that particular photocell.. Wouldn't there be another photocell that would in fact be sensitive enough to react to the warning light and lower the sensor voltage below 1VDC?

 

When I use this particular photocell and a small flashlight (instead of the warning light) I get a 4+VDC reading when the light is not on the photocell but when I move the light towards the photocell at about 0.9VDC the Sensor switches to ON on the ISY. Although the Sensor Status Light turns green at about 3VDC, this seems to have no bearing at all on when the ISY sees the change! It seems that a photocell with the ability to yield a sensor voltage of less than 1VDC when the warning light is ON and anything above 1 VDC when the warning light is off is enough of a range to trigger the Sensor on the ISY.

 

This suggests to me that the light sensitivity of the photocell is not acute enough and I would think that there must be others that are more sensitive... however, as I think that it might be a laborious task finding the right one, I am heading down the Micro Module path for now.

[GDavis01]

Stu... Thanks. I will order the micro module and then try to install it when I am next up here. Yes there is a neutral to the warning light.

[Brian H]

The Micro Module maybe a better way to go.

From what I can see in your photos. The indicator light looks like a Neon Indicator assembly. They don't put out a great amount of light.

[larryllix]

A phototransistor should work better. Lights acts as an input to the base of the transistor and they switch cleaner with the amplification of the transistor.

[Brian H]

A phototransistor. That may work much better.

I will have to see if I have any to play with in my components boxes.

[GDavis01]

The Micro Module needs line and neutral. One side of the warning light should connect to neutral, does it (it's difficult to tell from the image as all wires are black)? If so, then connect the other side of the warning light to the yellow (#1) sense wire of the Micro Module. Cap (tape) the purple (#2) sense wire.

 

 

I received the Micro Module and I reread your note... and I am confused! On the one hand you say that the module needs "line and neutral", but then you say to only connect the yellow sense wire to the "other side of the warning light" and cap the purple wire! I presume that I actually need 2 connections... correct? If I am connecting the yellow sense wire to the line side of the warning light then how am I getting the neutral?

 

The next question relates to how to connect the module to my ISY! Do I have to worry about the differences between Latching, Single and Dual Momentary modes?

[stusviews]

You need three connections to the Micro Module, the first two are line and neutral for power. One side of the warning light is already connected to neutral. The other side of the warning light receives a signal when something is amiss. That side of the warning light connects to the Micro Module sense wire so that the Micro Module also receives a signal when something is amiss.

 

You can add the Micro Module to the ISY like any other Insteon device. Select Latching, Single. Create a scene where the Micro Module is a controller and any other device(s) as responder. When the warning light is activated, any responder(s) will be activated, too.

[GDavis01]

Thank you... that makes a lot more sense to me. Now I just have to set it up...

[GDavis01]

Stu... I installed the Micro Module and it works well. Given the instructions, it was quite easy to setup. Thanks.

 

A question on programming...  here is the program I setup

 

If

    Control 'Septic Micro Module' is switched On

 

Then

 

  Send Notification to 'Me' content 'Septic Warning ON'

 

Else

 

  Send Notification to 'Me' content 'Septic Warning OFF'

 

 

The If / Then  works well and I receive the notification, when the alarm is triggered, but the Else doesn't do what I want, which is to send me an email when the alarm turns off! Should I simply add another program with the If statement "Control 'Septic Micro Module' is switched OFF" and Then Send Notification to 'Me' content 'Septic Warning OFF'?

[stusviews]

Else never gets triggered. The If statement is triggered only if the module is switched on. Simply add

 

       Or Control 'Septic Micro Module' is not switched Off

 

When the Micro Module is switched off the trigger statement becomes false and statements under the Else clause are executed.

 

 

Consider this statement, "If the sun shines, then I will go to the beach."

 

The sun does not shine, but I go to the beach anyway. Is my statement false? No, it's not. I only said what I'll do if the sun shines, I did not state what I'll do (or not do) if the sun doesn't shine.

[GDavis01]

Once again... thanks. 

[brjohnso]

I was looking at this same problem. Why can't I just get a micro module (any type) and connect sense wire 1 of the micro module to the alarm light bulb (it's 120vac). Power for the micro module is readily available from the line in to the septic controller. I suspect that the sense wires draw little to no power, so this should work. I suppose I could connect the sense wire to the buzzer circuit, which would certainly have enough oompf to drive the sensor wire of the micro module. Once connected, I can just monitor the state of the module with the ISY. Since the Insteon modules are dual band, it should work even inside a metal enclosure. No batteries and no relay required.

[stusviews]

The sense wire draws no power much like a standard switch doesn't. It's not the wire load that matters, it's the load that the Micro Module controls that is of concern. A Micro dimmer should be connected only to a device that can be dimmed, an On/Off module load should not exceed:

15A/240VAC
3600W/240VAC resistive
700W/240VAC inductive/capacitive
2000W/240VAC bulbs/low voltage halogen

[brjohnso]

The sense wire draws no power much like a standard switch doesn't. It's not the wire load that matters, it's the load that the Micro Module controls that is of concern. A Micro dimmer should be connected only to a device that can be dimmed, an On/Off module load should not exceed:

15A/240VAC

3600W/240VAC resistive

700W/240VAC inductive/capacitive

2000W/240VAC bulbs/low voltage halogen

 

 

Since there will be no load, it shouldn't matter then. It's only used for monitoring the state of the light. I don't plan on connecting the load to anything. Only the sense wire, and line in, and the common.