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Thread: novar sensors
02-27-2010, 10:17 PM #14Regular Guest
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- Feb 2010
I appreciate the info, and did not mean to come off rude if I did so in my original response. One final question and i'll leave this topic to rest-since the case sensor is a 5Vdc input with a millivolt return, how would the wiring look? The sensor i'm looking at (which I was informed was a case sensor) has 2 wires (red and black leads in a gray jacket), I would think there would have to be 3 for this (signal, common, and 5Vdc) based on what I have seen in the past.
Again, thanks for the info, you've been a great help.
02-28-2010, 08:00 AM #15
You again said input referencing the 5vdc. I am trying to correct you on this so you separate these details out in your mind.
On a Case Input Module. You have 8 available "ANALOG INPUT" spaces (Board Point 1, Board Point 2, Board Point 3, ect) where 8 temperature sensors would be attached.
A space for one sensor is 2 wires that attach on the board at let say station 1. Were gonna land the sensor wires on Board Point #1. On Board Point 1, you have a 5v signal and a common. The sensor will create a resistance through it so the board point interprets this as a temperature reading.
Previously you were trying to call the signal, the 5 vdc as it's outputting something. And it is. It's sending the 5 vdc out to the sensor. But for the sole purpose of getting back a translated/altered electrical signal back to the board (CIM) to be interpreted as a temperature. You have been wanting to call this an output and I am trying to tell you not to because in the EMS world, talking to an EMS versed refrigeration guy, he won't understand why your using the word output when your talking about an input. Actually, your talking specifically about an "Analog Input". There are other kinds of inputs.
5vdc and common. 2 wires. attached at one end to the case sensor and on the other end at the board on point 1 let's say. 5 vdc signal is sent out, and the signal goes through the sensor to common. the resistance through the sensor alters/changes the 5 vdc. And that signal then, let's say it's 3.2345678 measured on your meter at the board on it's point. That might represent the temperature 36.76 degrees."The only real security that a man can have in this world is a reserve of knowledge, experience and ability." Henry Ford
02-28-2010, 11:56 AM #16Regular Guest
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- Feb 2010
Agreed, my terminology could use a tune up apparently, I should have probably used 'supply' when referencing the 5Vdc. I was thinking of this scenario from a standpoint of say, a Danfoss module, where you have 8 pairs of signal/common, and then the separate 5Vdc, and 12Vdc supply voltages, which in my mind meant a wire to the 5Vdc terminal for supply, and then the millivolt return measured across the signal and common terminals.
02-28-2010, 01:12 PM #17
okay. you know danfoss. Just a different color really. The CIM is nothing more than a danfoss 8 point input board, they just do it a little different. All the manufacturers are the same with just a small twist so they can be different.
Now. On A danfoss input board between point 4 and point 5 you have 5 vdc and 12 vdc power. Those are used for ANALOG sensors that require an additional power source in addition to the 5 vdc signal to the input. An example of this would be leak detectors and pressure transducers.
So those are 3 wire. The signal and return, those two go to the input. The signal on danfoss, cpc and novar is 5 vdc. But that is separate from the power source needed for that particular sensor such as the pressure transducer. Depending on the type of sensor needing power, it might either need a separate voltage source of 5 or 12 VDC.
On CPC and Danfoss, you can use the input point as an analog input, such as temps, pressures and such, as well as a digital input like a door switch or compressor proof. We can define the input point in programming. The point itself can deal with it whether it's digital or analog.
On the Novar CIM module, they have 8 inputs, analog only and a 9th input to be used as a digital input generally only used for a dual temp input switch. The CIM, ROM, all of the refrigeration and HVAC from Novar is outdated when you compare them to CPC and Danfoss. Controllers too. Now Novar is about to launch their "OPUS" if they have not already. And you know what. It's a Danfoss 255 system rebadged as a Novar.
But it goes further than that. Danfoss 255 and now the OPUS from Novar are nothing more than rebadged versions of the Original Manufacturer of this very configurable and universal LON based system. It's called the NIAGARA Framework."The only real security that a man can have in this world is a reserve of knowledge, experience and ability." Henry Ford
02-28-2010, 09:05 PM #18Regular Guest
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- Feb 2010
Gotcha, this all makes sense, thank you again. You said the signal terminal supplies 5Vdc to the input, is there a current associated with that as well on these modules? Hate to keep asking questions, but each answer seems to open another can of worms.
03-01-2010, 06:05 AM #19
Not that I am aware of. Sensors are resistors in reality. So when you send the 5vdc to it from the INPUT, it will resist, depending on the temperature. This feedback is your "input". I have never tried to measure the current."The only real security that a man can have in this world is a reserve of knowledge, experience and ability." Henry Ford