Pre-purchase phase: system design

If you need help deciding on what monitor to get, which current transformers should you purchase for your panel, or anything else along these lines, start a thread here.
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gosmond
Posts: 14
Joined: Thu Oct 27, 2016 9:00 pm

Pre-purchase phase: system design

Post by gosmond » Fri Nov 04, 2016 8:23 pm

I'm in the pre-purchase evaluation & design phase. I have a single-family home in the Bay Area (california,) 200A electrical service, currently only ~100A or less used. 1 main panel with the meter (not shown in my photos,) and currently 1 sub-panel where all the house circuits are.

---- START of Brultech QUESTIONNAIRE--------
- Are there any budget constraints to work within?
I'm happy to spend whatever is reasonably necessary to achieve my desired setup.
- How do you plan on communicating with your router?
10/100 Ethernet (1000Base-T capable)
- What energy monitor you're considering purchasing? (if known)
GEM + DashBox
- Do you plan on using pulse counting? And if so, how many?
In the long run, yes. I would probably use all 4 pulse outputs. I understand the difference between the voltage-pulsed vs. dry-contact outputs & can adjust/interface accordingly as required.
- Is this a single-phase or 3-phase install? (If it's not your average residential install)
Well, "single phase" I guess, insofar as it's a standard residential setup with 2 separate 120V legs coming into the sub panel. Doesn't that make it "2 phases" technically speaking? Basically it's a standard US residential electrical service, certainly not 3-phase power.

For determining current transformers:
- How many circuit breakers do you wish to monitor?
All of them, which is 16 at present, but potentially up to 24 breakers if I convert all of them to slim-profile breakers. I have verified that my panel is rated for up to 24 breakers.
- What is the amperage of the above breakers?
Mostly 20A single pole with a few 15A breakers.
- Are there any 2-pole breakers?
At present, no. But I do plan to install 5 baseboard heaters. I may decide to go with 220V heaters to save 1.5% in wire losses compared to 120V heaters. In that case, I would have (5) x 20Amp double-pole breakers installed.
- Do any of the 2-pole breakers have no neutral? (This can reduce the amount of CTs needed) As I understand it, baseboard heaters just use 2 hot wires, no neutral, so I believe there would be no neutrals for the projected (5) x 20A double breakers I plan to install.
- What is the amperage of your main breaker?
125A 2-pole at present.
-------END of QUESTIONNAIRE-------

Continuing my discussion:

ELECTRICAL
- I have plenty of space in my panel and am fine with using Micro40's or Micro50's for the breakers. I am thinking of using SPLIT-200's for the main wires that feed the panel? I believe they are #6AWG, but with old-school insulation that is much thicker than modern #6AWG. Best estimate, they are 3/8" O.D."
- I want the most sensitive low-current / "vampire power drain" detection capability I can get. If there is any difference in low-current threshold between the Micro40/50/80, please describe.
- I want highly reliable and accurate voltage-sensing equipment. I.e. if you suggest something different than the included wall-wart, please advise on what that is & where to buy it.
- I plan to add about 4kW of solar-PV capacity and to set up net metering eventually, so I will want the GEM setup to monitor that as well when the time comes.
- I also use UPB (Universal Power Bus) programmable / communicating 120V switches and dimmers in my house wiring. UPB is basically a successor to X10, sending low-data-rate (4800bps) high-amplitude (~40-60volt) signals directly over the live house wiring for inter-device communications.

DATA/NETWORK
Please see the attached diagram of my planned data-logging / HA integration setup.

Needs:
• Hands-off energy logging & data storage (DashBox handles that)
• Immediate response from OpenHAB server to changes in circuit loads. On / Off / passing through preset current thresholds / KWhr-cumulative actions. I.e. I want OpenHAB to take immediate action on various loads for various purposes -- and still have the DashBox constantly & reliably logging data.

Wishes:
• Would prefer to have the OpenHAB & DashBox receiving separate & independent data feeds to remove chained points of failure. (OpenHAB listening directly to the GEM at all times, cutting out the DashBox middle-man as it were.) Open to either 10/100 Ethernet or separate RS232 channel for that, please advise.

• Completely hands-off, automated, regular backups of the DashBox data to some other location on the in-house LAN. (Not pulling out an SD card by hand every 6 months.)

Other notes:
• My HA LAN is hard-wired on new Cat5e and Cat6 w/ good switches and backup power. It's air-gapped from the internet and will remain that way for the forseeable future. I do not use wireless protocols for any HA functions.

QUESTIONS:
1 - Is it possible / how do I establish dual independent live data paths from the GEM to the DashBox and to my OpenHAB server. I will use whatever combination of Ethernet / RS232 / USB is best to accomplish this. I've read a lot of other threads and am still not clear on the limitations of the 2 serial ports on the GEM. Please advise.

2 - Are you familiar with UPB (Universal Power Bus) devices on the wire, do you know if they will cause any problems with the GEM or vice versa? (Seems unlikely, beyond possible momentary confusion for the CT's as they watch brief UPB data packets pass every now and then. UPB is not a chatty protocol, it only sends packets in response to direct input, i.e. when loads change state.) Also: Not installed now, but eventually I will probably need to install a UPB phase-coupling device, which I believe is a passive capacitor-based unit that inverts UPB signals before passing them to the opposite phase.

------

Proposed purchase list:
1 x GEM unit with Ethernet-only module.
1 x DashBox
1 x Package B, 2 split-100s + 6 micro-40's
1 x Package G, 16 micro-40's

----
My sub panel:
2016-11-04_16-25-58 copy.JPG
2016-11-04_16-25-58 copy.JPG (2.41 MiB) Viewed 14774 times
Proposed system sketch:
2016-11-04 Proposed Brultech GEM setup.pdf
(1.01 MiB) Downloaded 596 times
Last edited by gosmond on Sat Nov 05, 2016 3:12 pm, edited 1 time in total.
wci68
Posts: 43
Joined: Thu Dec 17, 2015 4:31 pm

Re: Pre-purchase phase: system design

Post by wci68 » Sat Nov 05, 2016 8:35 am

gosmond wrote:I'm in the pre-purchase evaluation & design phase. I have a single-family home in the Bay Area (california,) 200A electrical service, currently only ~100A or less used. 1 main panel with the meter (not shown in my photos,) and currently 1 sub-panel where all the house circuits are.
Is that a single "box" with the meter in half and a primary disconnect (main breaker) in the other half? That breaker should be sized according to the conductors that feed your second panel. A pair of split-200 CTs would likely be best for those, and would be placed in the second panel above the lugs (you have lots of room in there)
- Is this a single-phase or 3-phase install? (If it's not your average residential install)
Well, "single phase" I guess, insofar as it's a standard residential setup with 2 separate 120V legs coming into the sub panel. Doesn't that make it "2 phases" technically speaking? Basically it's a standard US residential electrical service, certainly not 3-phase power.
Technically it is a "split-phase" (which is standard for US residential) but this is an often-confusing detail. It is single-phase for discussions such as this.
- I have plenty of space in my panel and am fine with using Micro40's or Micro50's for the breakers. I am thinking of using SPLIT-200's for the main wires that feed the panel? I believe they are #6AWG, but with old-school insulation that is much thicker than modern #6AWG. Best estimate, they are 3/8" O.D."
#6 would far too small for even a 100A service so they are likely larger than that.

A 200A service would need to be a least 2/0 and in many cases would be 3/0, for copper. A 150A service would typically be 1/0 and the split 200s fit around those with plenty of room. It is difficult to tell from a picture but it looks like the feeders in the photo you posted could be 1/0 but even if not the split 200s should be good.
1 - Is it possible / how do I establish dual independent live data paths from the GEM to the DashBox and to my OpenHAB server. I will use whatever combination of Ethernet / RS232 / USB is best to accomplish this. I've read a lot of other threads and am still not clear on the limitations of the 2 serial ports on the GEM. Please advise.
The GEM can (does) provide two "feeds", either polled or published. The ethernet/wifi/radio options will each use one of those two. You can feed the Dashbox via one serial and OpenHab via the other. It appears the Dashbox can now in turn publish a feed to other solutions but as I do not yet have a Dashbox I have no detail on this.

How do you plan to feed OpenHab? You could potentially use something like btmon to poll the GEM via serial, then feed multiple other solutions in turn including a basic SQL database. If you will be going with a Dashbox you would be duplicating its functionality at least partly. You noted you wanted backup and/or redundancy, however, so that might be a good way to go.

I currently am using btmon to poll my GEMs and feed both a mysql database as well as EmonCMS, which has its own time-series database. I do plan to add a Dashbox at some point.
gosmond
Posts: 14
Joined: Thu Oct 27, 2016 9:00 pm

Re: Pre-purchase phase: system design

Post by gosmond » Sat Nov 05, 2016 3:17 pm

Thanks for your reply.
After reading & thinking some more, my main question is:

With the base GEM (no communication modules) there are 2 serial ports available. If I add, say, the Ethernet module, does that take one of the serial ports out of service?

I.e. is the GEM+Ethernet TWO available RS232 ports + ONE Ethernet port?
Or is the GEM+Ethernet ONE available RS232 port + ONE Ethernet port?

--

For other readers following along, my question about UPB still stands:
2 - Are you familiar with UPB (Universal Power Bus) devices on the wire, do you know if they will cause any problems with the GEM or vice versa? (Seems unlikely, beyond possible momentary confusion for the CT's as they watch brief UPB data packets pass every now and then. UPB is not a chatty protocol, it only sends packets in response to direct input, i.e. when loads change state.) Also: Not installed now, but eventually I will probably need to install a UPB phase-coupling device, which I believe is a passive capacitor-based unit that inverts UPB signals before passing them to the opposite phase.
ben
Site Admin
Posts: 4254
Joined: Fri Jun 04, 2010 9:39 am

Re: Pre-purchase phase: system design

Post by ben » Mon Nov 07, 2016 11:19 am

gosmond wrote:Thanks for your reply.
After reading & thinking some more, my main question is:

With the base GEM (no communication modules) there are 2 serial ports available. If I add, say, the Ethernet module, does that take one of the serial ports out of service?

I.e. is the GEM+Ethernet TWO available RS232 ports + ONE Ethernet port?
Or is the GEM+Ethernet ONE available RS232 port + ONE Ethernet port?

--

For other readers following along, my question about UPB still stands:
2 - Are you familiar with UPB (Universal Power Bus) devices on the wire, do you know if they will cause any problems with the GEM or vice versa? (Seems unlikely, beyond possible momentary confusion for the CT's as they watch brief UPB data packets pass every now and then. UPB is not a chatty protocol, it only sends packets in response to direct input, i.e. when loads change state.) Also: Not installed now, but eventually I will probably need to install a UPB phase-coupling device, which I believe is a passive capacitor-based unit that inverts UPB signals before passing them to the opposite phase.
1. Ethernet and WiFi/Ethernet run on COM1, Zigbee runs on COM2. Either port can still to listened on through the Tx line, just can't connect the Rx if there's a module connected due to conflicting receives.

2. UPB shouldn't cause any issues.
Ben
Brultech Research Inc.
E: ben(at)brultech.com
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