400 Amp System

[pkgibbs]

The home we moved into several (~5) years ago is using quite a bit more electricity than I had anticipated, particularly in the winter months. I am considering an energy monitor to determine where its going and could use some help figuring out what exactly to buy.

Electrical configuration:
400 amp 240 volt service
(2) 200 amp breaker panels in mechanical room fed by 200 amp breakers near service entrance
100 amp subpanel in workshop
7kW photo voltaic system with micro inverters (Enphase) feeding through a dedicated subpanel

Circuits I want to monitor initially (all in the main panels which are side by side):
(2) 50 amp 240 volt
(1) 30 amp 240 volt
(6) 20 amp 240 volt
(1) 20 amp 120 volt

I can envision at some time in the future wanting to monitor more/all of the circuits in the main panels, the shop subpanel and the PV subpanel. I would like a system configured so that I could easily expand to this in the future but I think this will get me the information I need for now.

The 240 volt circuits are all or most without neutrals but I will probably monitor both legs. I have not decided whether to monitor the 200 amp feeds to the main panels or not.

What I am thinking I would start out with:
Green Eye Monitor
DashBox
(4) Split-200's
(4) Micro-80's
(15) Micro-40's

From a $ perspective the best that I have come up with would be to get a System 2 bundle and add
(2) Split-200's and (3) Micro-40's.

My questions:

1) The bundle includes Micro-80's and Micro-40's. Is the improved accuracy of the Micro-100s/Micro-50's enough to warrant forgoing the bundle pricing and putting together a package utilizing the Micro-100/Micro-50 CT's? I thought I had seen some curves depicting the response/accuracy of the Micro-50's but can't find it now. Would it be advisable to utilize the Micro-100's for the 50 amp, 240 volt circuits, if I go this route?

2) Are there good reasons to monitor the main feeds if all I am really trying to track at this point are the branch circuits that I believe to be the main culprits in increased electric utilization?

3) If I wish to expand in the future I could see ultimately (2) GEM's monitoring the main breaker panels (wouldn't be enough to monitor all 80 circuits but I could combine circuits or only monitor 1 leg of the balanced 240 loads and make it work), an ECM-1240 on the PV subpanel, and either an ECM-1240 or GEM on the shop sub-panel. Can the DashBox handle this many monitors? Can an ethernet module be added later to a GEM or does it need to be installed when purchased?

I think that is all my questions for now. I am certain I will come up with more as I get into this further but I will ask them as I go along. Thanks in advance for your help.

Phil

[Teken]

Hello Phil,

You can submit a custom order to the company and they will outfit the package to your needs. I would humbly suggest you spend the extra money for the higher tolerance CT's as the difference between the two is so marginal in the grand scheme of things.

This is a long term investment and the extra costs for the CT's will be long forgotten in a year. I would always monitor the main feeds regardless from both panels. I believe the DB can support two GEM's and one ECM-1240 at a time.

I would encourage you to purchase the WiFi / Ethernet option from the onset for the best connectivity.

[ben]

1) If you decide to go with the 50s, check the diameter of the cable for the 50A load. If it fits into the inner diameter of the CT, you should be OK there (in 95% of cases, it fits fine). http://www.brultech.com/current-sensors/.

2) Tracking mains is useful if you want to compare overall usage to your power bill. The issue with summing all the loads and using that is that you include all possible error from every CT.

3) We've had a couple 3 GEM installs with a DashBox so it is possible. You'd definitely want to look at upgrading the storage on the DashBox. It comes with a 16GB Micro-SD card, which is good for about 1 years worth of minute data for 2 GEMs, so you'd likely want to swap in a 64GB card (a good quality Micro-SD card, MLC flash).

[Teken]

As a point of reference I'm using a 128 GB Micro SD card from Samsung with excellent results. As Ben noted using only the highest quality memory cards like Transcend, Samsung, Lexar, etc is mandatory.

[ben]

As a point of reference I'm using a 128 GB Micro SD card from Samsung with excellent results. As Ben noted using only the highest quality memory cards like Trandcend, Samsung, Lexar, etc is mandatory.

We've recently switched from Transcend 16GB cards to Samsung Pro 16GB cards as we've had a couple corrupt Transcend card. DashBox firmware has also been improved to stop all unnecessary writes to the flash, a lot of the packet processing now resides in memory instead.

- Samsung Pro (not sure about Pro+)
- Transcend High Endurance
- Transcend Ultimate
- Kingston Industrial
- Panasonic (looks like all their cards use MLC according to their website)

I'd look for cards rated for dashcams, go-pros, etc. Usually they use better quality flash as they're expected to be written/deleted from a lot.

[pkgibbs]

Teken and Ben, thank you very much for your responses.

I am not really concerned about the incremental cost of the Micro-50 CT's as compared to the Micro-40/Micro-80. However, the bundle offers a significant savings over purchasing the items individually and it is only offered with the Micro-80 and Micro-40 CT's, thus the question. While I agree with you that this is an investment, I want it to be a wise investment. More than an investment I view this as a tool to be utilized in resolving problems that arise. I see no sense in buying capabilities that I cannot use, particularly if they can be added at a later time for a reasonable cost in comparison to buying that capability now, should they be needed.

All that said, I will submit a request to BrulTech for a quote on a system with the configuration I am looking for.

I will probably monitor both panel feeds as I can see how this information would be really good in determining actual consumption as opposed to trying to derive it from the net meter, Enphase Enlighten and the power company bill.

I checked and the wire for the 50 amp breakers will fit thru a Micro-50 (<.25 diameter). Thanks for that heads up.

Is the limit to 3 monitors for the DashBox due to connectivity, hardware capacity, software or some other issue? Should I ever add more monitors I will keep your information regarding storage on the DB in mind.

Thanks again,
Phil

[ben]

Is the limit to 3 monitors for the DashBox due to connectivity, hardware capacity, software or some other issue? Should I ever add more monitors I will keep your information regarding storage on the DB in mind.

Connectivity isn't an issue as it can technically take unlimited devices via HTTP posts.

It's more about hardware capacity, and storage. The GEM has 32 channels, so 3 GEMs is 96 channels of data being posted at a regular interval. If you were to extend that send interval from the default (5 seconds) to 15-20 seconds, it might not be as much of an issue (besides the SD card having to work a bit harder due to the amount of data being inputted).

[Teken]

I truly believe given the fact you added in the capability for the DB to send its data to other IP / Ports. This allows a person many other methods of storage and graph viewing. This assumes storage capacity was one of the main drivers etc.

[pkgibbs]

Pulled the trigger! Now, finding the time to install and configure (the way I want it done) will be the issue. Thanks for your help.

[Teken]

Pulled the trigger! Now, finding the time to install and configure (the way I want it done) will be the issue. Thanks for your help.

Congratulations and take your time doing all the prep work first. Doing so will ensure a smooth install and reduce the frustration that may come.

Label everything at both ends of the CT's and don't cut any wire until you're 100% sure the final placement is finalized.