Testing 1000 gallon pressurized storage tank

[goosegunner]

I have 1-1/2" X 1-1/2" X 1/2" T's installed before and after the Danfoss. Female street adapters with brass wells for temp gauges. For what the fittings cost I would use the sensors that you put on the pipe. A Azel would work well if you want something quick.

gg

 

[jebatty]

How about something like this? The digital panel meters are about $15.00 each, the box is a standard electrical box in which I simply made cutouts for the meters. The sensors are Dallas DS18b20 (others available) which come with the meters. You will need a 12-24vdc power supply. The simple wall transformers work well. Standard thermostat cabling works fine, or Cat 5 does the trick also.

 

[Gasifier]

goosegunner and Jebatty, thanks for the info. What did you think about my first question? Jebatty, I have seen your panel in a prior post. Slick. If I put one of the sensors on the outside of the pipe after danfoss is that going to be fairly acurate? Or not even close to what is on the inside. Thanks again.

 

[goosegunner]

How about something like this? The digital panel meters are about $15.00 each, the box is a standard electrical box in which I simply made cutouts for the meters. The sensors are Dallas DS18b20 (others available) which come with the meters. You will need a 12-24vdc power supply. The simple wall transformers work well. Standard thermostat cabling works fine, or Cat 5 does the trick also.

Jebatty,

Does one power supply provide power for all of your meters?

Do you have any pictures of the inside of the box?

gg

 

[jebatty]

If I put one of the sensors on the outside of the pipe after danfoss is that going to be fairly acurate?

Almost all of my sensors are on the outside of the pipe. I use aluminum tape to stick the sensor to the pipe, also cable time the sensor to the pipe; then wrap with insulation. Of course, the pipes themselves I also insulate. I can't tell you the temperature difference between the outside and inside of the pipe, but I try to mount the sensors if possible fairly close on the downstream side of an L, thinking that the water is more turbulent and mixed at this point and that the outside temperature of the pipe will be closer to the inside temperature. My readings are good enough for whatever I purpose I need them.

Does one power supply provide power for all of your meters?

Yes, one power supply. Meter draw is pretty low. I would think a 1 amp 12 vdc supply would handle up to 12 meters or more, or use up to a 24vdc supply.

There is a mess of wire inside the box. Each meter has a two conductor power supply plug + a 3 conductor plug for the DS18b20 sensor. You can't 1-wire all of the sensors together, each needs its own cable. 3 conductor thermostat wire works well, and if the run isn't too long, Cat 5 also works, and you can get three meters per cable run. The ground wire can be shared.

 

[mwk1000]

One thing that appears to be causing some of the issues was the digital boiler temp gauge reads 10 degrees higher than the gauge in my supply pipe. I have increased boiler set point to 195. Boiler temp gauge is hovering around 185 and the gauge in the supply right after boiler says about 175.

This always drives me crazy. Mine is often over 10 off. I have much the same situation when I start with a really cold tank, Like now in the shoulder season I'll let it drop to below 80 before charging again. For an hour or two the EKO 60 return temps would drive the temps slowly down and I would get this weird cycle going of danfoss closing more and more as the return temps were so low that the boiler was slowly dropping . I used to play with the mixing valve when very cold until I finally added a 140 degree return check to my controller software and just stop the heat exchange when the return water drives the boiler temp to low. This helps keep the danfoss open and I just see a few cycles on the charging side as I let the boiler "rest". If I get ambitious I'll work on better logic but I don't touch my mixer valve any more.

 

[diptek]

Jebatty,

Is your panel set up for Data logging, or just for display? If you are data logging, more details please.

Thanks,
Walt

 

[jebatty]

The panel is just for monitoring. There may be a way, and I would guess there is with other hardware, to use the same sensor for the panel meter and for data logging. What I did was place two DS18b20 sensors side by side at each location, one for each meter and the other on a 1-wire bus for data logging. The meter reads and the data log reads are virtually identical. There is very little extra cost. I got meters with two sensors each, as each meter does have two channels; I use only one channel and I used the second sensor for the data bus. The cost per sensor is about $6.

You can make up your own sensor package by buying the DS18b20's for about $2 each, but the time time to wire and then encase made it worth buying the pre-made sensor packages.

My data logging hardware is from (broken link removed to http://www.pcsensor.com/index.php?_a=viewCat&catId=4). You also can get sensors from them. Their hardware/software produces a chart + a comma delimited text file which can be manipulated and managed by a variety of other software. I use a database program to read in the text data file and then do the manipulation and management to produce whatever end product I want. It has worked very well for me. Good familiarity with a database program with charting or a separate charting program would be very helpful.

 

[Blevesque]

Jim where are you getting your panel meters. I can't find them for $15 anywhere.

 

[ewdudley]

panel meters $15 .

Search ebay for just 'DS18B20', sort by price plus shipping, and then go to $15.

 

[Blevesque]

Here is what I found, will these work? Brian

(broken link removed to http://www.ebay.com/itm/Digital-LED-Thermometer-Temperature-Auto-Car-Meter-C-F-/250899235462?pt=LH_DefaultDomain_0&hash=item3a6ac28286)

 

[ewdudley]

Here is what I found, will these work? Brian

(broken link removed to http://www.ebay.com/itm/Digital-LED-Thermometer-Temperature-Auto-Car-Meter-C-F-/250899235462?pt=LH_DefaultDomain_0&hash=item3a6ac28286)

Those appear to be the same as what Jim is using, blue, red, same difference as long as they have the DS18B20 sensors. I got a batch from Sure Electronics that worked fine with the one meter leads, but they wouldn't work with leads extended with Cat-5 out to four or five meters until I added a pull-up resistor to correct the bus timing, YMMV.

The one you've shown has one sensor, but it will accept two I believe. As Jim notes above, there are other listings that have the same display with two sensors with the second sensor cheaper than buying extra sensors alone. If you want extra sensors for data logging later on it you can get them cheap by ordering the two sensor displays and saving the extra sensor for data logging.

 

[jebatty]

...worked fine with the one meter leads, but they wouldn’t work with leads extended with Cat-5 out to four or five meters until I added a pull-up resistor to correct the bus timing...

Last week I finished installing the Deep Portage monitoring panel with 16 of these panel meters, furthest distance was about 13 meters. All worked fine on Cat 5e. I used both greens for a common ground to all meters; and both oranges for +v, and both of either the browns or blues for the data. The power supply was a plug-in power supply/transformer from an old laptop of mine which provided 16vdc @ 3 amps. I soldered all splices/connections.