Week 7 Update - Current Transformers

Hello

Remember last week, how I used a current transformer in order to measure the voltage coming from the Light Bulb. Turns out it was actually a Current Transducer and I did not need the Resistor. With the resistor I get 52 millivolts and without it I get around 170 millivolts. Anyway, I calculated the Amperage using Ohm's Law which was 50 Watts (Wattage Rating for the Bulb)/120 Volts = 0.416 Amps. 

Remember how this current transducer is 5 Volts to 10 Amps. This means that 5 Volts gives me 10 Amp, 2.5 Volts gives me 5 Amps, 1 Volts gives me 2 Amps, etc. There's a pattern here. Volts multiplied by 2 gives me the Amps. So, I multiplied 170 millivolts by 0.001 to get 0.17 Volts which I then multiplied by 2 to get 0.34 Amps. My professor then removed the current transducer and used a Clamp-On Ammeter and got 0.34 Amps.

Now, I understand that a Current Transformer works like a Step-Down Transformer in that the current on the primary and secondary are proportional to one another. The primary has a larger current and the secondary has a smaller current. I plan to re do what I did last week with the Light Blub and integrate this with my BASpi. 

Anyway, I got an ELKOR SCT2-101 Current Transformer, which I included a picture of above. I replaced the current transducer from last week with this and set to work and put a 1K Ohm Resistor between the Hot and Neutral (Black and White) wires because without it the Circuit would gain extremely high voltages and kill me. This CT has a ratio of 100:5 which means that 100 Amps gives my 5 Amps, 50 Amps gives me 2.5, and 10 gives me 0.5. I calculated the amperage by dividing 60 Watts/120 Volts and got 0.5 Amps.

To get the expected voltage from my Multi-Meter,I divided 0.5/20  which is 0.1/4 which equals 0.025 millivolts. 0.025 multiplied by 1000 gives me 25 Volts. But, I ran into a roadblock, I didn't see 25 Volts displayed on my Multi-Meter so I changed the orientation of the CT a handful of times, as well as, replacing the 1K Resistor with 100 and 10K Resistors. Nothing. I got a Clamp on Meter which I included a picture of and measured the Voltage between the CT wires and got 0.2 Volts. Weird. But, this CT wasn't really useful in what I needed.

I then replaced that CT with a Micro Switch CSALA1CD Linear Current Sensor which you can see below:

This one had 3 pins and needed 8-16 Volts DC to operate, so I hooked up 2 of the pins to DC Variable Power Supply and the last pin to my Multi-Meter and ground.Turns out the Voltage reading is half of what you see on the power supply so 8 Volts = 4 Volts, 10 Volts = 5 Volts, etc.But, the data sheet says the Sensed Current is 57,but gave no unit. My professor came in to help me and he was also confused, more on which pins are what because the data sheet gives a side view and doesn't indicate which side. So was prong 1 Vcc or Ground? We didn't know. After some trouble-shooting we found that there was no current reading on my Multi-Meter, so we connected a Variac to control the brightness of the light, but the voltage reading stayed the same. Strange. 

Here are the datasheets for both CTs along with pictures of my setup:
http://www.elkor.net/pdfs/SCT2.pdf 
https://sensing.honeywell.com/honeywell-sensing-current-csla-series-catalog-pages.pdf

- Valentin

Week 6 Update - BASpi and Current Transformers

Hello

Today I wanted to connect my BAspi to a Current Transformer, but I ran into a roadblock. In Week 2, I changed the IP Address of my Raspberry Pi and now I wasn't able to access my BASpi. So, what I did was just reformat my SD Card. Here is a picture of my reformatting set up:

Next, I took a 5 Volt to 10 Amp Current Transformer and put around the Black wire coming from a light bulb. For safety reasons, I wrapped a 1K ohm resistor around the leads I put in the CT which I also had connected to my Multi Meter. I connected the White and Black wires from an electricty cable to the White and Black wires on the Light Bulb respectively. I didn't use the Green Wire on the cord. I plugged in the the cord and measured the voltage with my Multi Meter. I got 52 millivolts. Here are some pictures of my setup and I also included a picture of the CT I used above:

Since my CT is 5 Volts to 10 amps this means that if I have 5 Volts, I'll get 10 amps. 2 volts which get me 5 amps, and so forth. Put the cord is supplying the bulb with 120 Volts which is way over the 5 Volt scale, then why am I getting 52.0 millivolts?

Afterwards, I reformatted my SD Card agian, but I used a computer in C505 rather than my tablet. It only took a few minutes and when I hooked up my Pi, it booted up correctly and I was able to access my BASpi. Here is my setup:

Here is the guide I used to reformat my SD Card: https://www.ccontrols.com/pdf/is/BASPI-soft-install-guide.pdf. Next week, I'll hook up my BASpi again and start programming in Sedona, as well, as figure out how Current Transformers work.

-Valentin

Week 5 Update - Insteon Power Monitoring

Hello

The first thing I did today was do a comparison between the Electricity Meter and an Insteon Energy Display. I wanted to measure the Wattage from an LED bulb. Above I included pictures of the Insteon Energy Display and Meter I used.

Here are the pictures of my Electricity Meter setup:

 So the bulb is giving me 7.7 Watts. And here is my Insteon Setup with the Energy Display and Meter:

The Energy Display that was given to me had a cracked screen and when I tried to link the Display and Meter to display the Watts from the bulb and it did not work. Maybe it's because of the cracked screen? Anyway, I tried to do it again with my Tablet so here is the reading I got the Electricity Meter:

I got a reading of 11.9 Watts on the Electricity Meter and on the Energy Display I got nothing. I waited for about 5 minutes and the display just beeped loudly and nothing. I'll just have to buy another one. Anyway, here is a link to the manual for the Energy Display: http://cache.insteon.com/documentation/2448A2-en.pdf

My professor got me another Energy Display and I gave it another shot. I tried to read the Wattage from my Tablet and from the Bulb and it still did not work. I followed the instructions to a T and it still didn't work. Is there something I'm not getting here? Does the Display have to be a certain distance from the Meter? The manual doesn't say so. 

Honestly, I don't trust this Display. Why should I wait for 2 devices to link when I can use just 1 and get instant results.

For now, I give up on the Energy Display. Now, I grabbed the WattNode BACnet Power Meter my professor gave me and looked up the manual so that I could wire it and figure out how it works. Since my professor wanted data on the Cloud to be one of the requirements of all Capstone projects, I figured since this is a BACnet device... I could take the readings from the BACnet and put them into the cloud. Here is a picture of the WattNode BACnet Model: WNC-3Y-208-BN:

After that, my professor tried to do use the Insteon Energy Display and Meter and it still didn't work. He tired a few more times and even read the instructions as carefully as possible and it didn't work. There's another reason I don't trust the display. I read through the manual for the WattNode seeing how the Current Transformer are wired and how the BACnet works

-Valentin

Week 4 Update - C505 and C305 Power Monitoring and Fixture Counting

Hello

The first thing I did today was calculate the total power consumed in C505. Like last week I found the source of the power which was an outlet in which all the powers bars were connected to. In C505 we have computer benches like in C527, as well as, a wall containing our lab projects like DSC alarm panels, electrical wiring, and smart switch panels.  Like last week I connected everything to the power bars and all the power bars to the source outlet. I plugged in the Electricity Meter and took a reading of 461 Watts.  After I took the meter I found out that all the computer on the bench went out. I thought the bench and the wall were separate, turn out I was wrong. I think I'll do this again next week with the help of one of my professor's to take an accurate reading. 

After that, I got a different Light Meter from one of my professor's and took lux readings around C505 again. Here are the lux readings from the 9 points:

• Point 1 = 947 Lux
• Point 2 = 802 Lux
• Point 3 = 635 Lux
• Point 4 = 557 Lux
• Point 5 = 515 Lux
• Point 6 = 344 Lux
• Point 7 = 519 Lux
• Point 8 = 467 Lux
• Point 9 = 463 Lux
• Average = 421.75 Lux

These readings are different that the ones I too last week because there is more of them and I took the readings by placing the light meter on the desk rather than on a cart in the corners of the room. Also since I used a different light meter, this one could be calibrated differently than the other one.

Afterwards, I was told I should figure out constantly monitor the power in a room.  I researched power monitors found a get one, but it was expensive. Anyway, my professor gave me a power monitor, but he wanted it to get permanently fixed to the Circuit Breaker in C505 so he suggested to use a CT (Current Transformer). I'll look into this next week,but I included a photo of the power monitor my professor gave me.

Next, I took the Electricity Meter and went to C305 and calculated the total power being consumed. From the source I got a reading of 1.1 Watts then I multiplied it by the 20 benches to get 22 Watts. The reason the Watts is so low is because only the two computers are on and not the electro-pneumatic and PLC stations. Next week, I plan to go back to get the true calculation. 

For the number of fixtures, there were 6 fixtures in 1 row which I multiplied by the 7 which the total number of rows. I also added in the 4 fixtures in the back to get a total number of 46 fixtures. 

For the total number of lamps, there were 2 lamps per fixture so I multiplied 2 by 6 to get 12 and then multiplied 12 by 7 and added in the 4 lamps in the back to get 88 lamps in total. 

-Valentin