solar on sub-panel

[geekfarmer]

I am getting solar installed and will have it attached to two different sub-panels. The two sub-panels are about 50 to 60ft from the main, and I have two 200amp main panels. What do I need and how do I configure the system to monitor both total usage and solar generation.

[pfletch101]

This may be a bit of a challenge because of the distances involved. Can you give us a simple sketch showing how the two subpanels and two main panels are connected to each other and to the utility mains?

[geekfarmer]

The 2 sub-panels are off main 1. A backup generator is on main 2. Sub 1 is my greenhouse and has a 60 amp service. Sub 2 is an outbuilding and has a 50 amp service. My solar is split into 2 5kw strings. Did not have room in sub 1 for both sets of breakers. The total run to sub1 is about 60 ft. (possible a little more). The distance to string 2 is 50 ft. I have Intone switches and thermostat in the outbuilding and they work via the PLC.  Was hoping TED also work.

[pfletch101]

I don't see a promising way of configuring your setup using TED Pro Home components. You need too many 'main' monitoring points - corresponding to TED's MTU/CT combos - and the Home system is limited to two of these. I imagine that their Pro Commercial kit could be configured to monitor your setup, but I also imagine (I have no personal experience of the Commercial kit) that it would be much more expensive, and believe that you would also have to run network cable between the boxes. Sorry to be a wet blanket - others may have more positive thoughts.

[geekfarmer]

Tks. I think I can still make it work. The solar system comes with its own reporting system. If I get two mtus and a spider mix on each one I can monitor everything. Will have to do some math to see what the greenhouse relay used. Not the way I was hoping for but better than nothing.  I did look into the commercial version. It only works with 208 or 277v. Not 240.

[pfletch101]

Yes. If you use the solar system's own monitoring to track its production (generally the most accurate way of doing it) and don't mind doing some math, you should be able to do most of the rest with a TED Pro Home system. I'm still not sure whether you will be able to monitor the Backup Generator and any loads on panel 2, though. There appears to be a 'plain' Pro version which supports 4 main MTU/CT pairs on single phase circuits, but I can't find any specific information about it.

I also knew that you need the Commercial version to deal with three-phase layouts, but I don't think that the reverse is true - I believe that it can be configured to work with single phase layouts, if they are complex enough or high-power enough that the Home version isn't sufficient. The documentation implies, however, that you may lose some accuracy (over using the Pro Home) if you do this.

[Support7]

Hi geekfarmer,

Either version of the TED system can handle up to 4 total MTU's and 4 Spyders so you should be able to cover your monitoring points but in order for the system to do the NET usage math considering the solar you will need at least 2 MTU's (1 for load and 1 for generation). Also the TED Pro Commercial will work on single phase 240V, if you saw on our website anywhere that said it only works on 208V or 277V please let me know where and we will get it corrected.

I know you said your sub panels were about 60ft or more away from the main but are the 2 mains next to each other? Are the 2 sub panels next to each other? If they are, we do have harnesses available that can run CT's in parallel with each other so as long as you don't need to see each line of the solar separately then you could use 1 MTU just for your solar so that would allow you to use the remaining 3 MTU's for 3 of your panels and depending on proximity of the panels to each other then you could use a Spyder for your remaining panel but the Spyders do have to be connected to an MTU to communicate with the system so 2 of the panels would have to be physically next to each other for that to work. There's also the consideration that the MTU's provide real-time readings as where the Spyder only provides down to the minute polling and isn't as accurate as the MTU.

You may run into PLC interference issues with the TED Pro Home considering your setup and other PLC system but I have not heard of any known issues with TED and Intone conflicting with each other. I'm not familiar with Intone either so I couldn't say for certain either way but it is possible. Using the TED Pro Commercial Ethernet communication option would eliminate the hassle of troubleshooting PLC interference as long as you have a network drop close to where the panels are located so you can connect an Ethernet cable to the MTU.

In order to get the harnesses and exactly what you need for your install you should contact our sales department at 800-959-5833 and they can help you customize the system to fit your exact specifications.

For troubleshooting or if you run into any questions please let us know by going to http://www.theenergydetective.com/ticket and fill in the requested information to submit a support ticket so we can work to resolve any issues that may arise ASAP and make sure we provide the right firmware for any updates requested or required.

Have a wonderful day!

TED Support
www.theenergydetective.com

   

[pfletch101]

Either version of the TED system can handle up to 4 total MTU's and 4 Spyders

I am sure that your statement is true, but your doc and advertising writers need to look at making this clearer. Although the Pro Home installation and use documentation nowhere states explicitly that it is limited to two MTUs, I couldn't find any reference in it (except, now I look harder, in the general Pro Specification document) to the use of more than two - which I had taken as implying that this was the limit. It probably adds to the confusion that one MTU can support two Spyders but the system can only support a total of 4 Spyders, so Spyder docs also only refer to the first two MTUs.

[geekfarmer]

The two sub panels are not next to each other. One is in my greenhouse the other is in a shed. The two main panels are next to each other. I don't care if I monitor the backup generator. I could get a system with two MTUs and put one MTU on the sub panel that is the furthest. If it works then get more MTUs.

[pfletch101]

The two sub panels are not next to each other. One is in my greenhouse the other is in a shed. The two main panels are next to each other. I don't care if I monitor the backup generator. I could get a system with two MTUs and put one MTU on the sub panel that is the furthest. If it works then get more MTUs.

Do you need to break down the load on either of your subpanels on a circuit by circuit basis? If you do, then you will indeed need to locate an MTU at the subpanel(s) to support the necessary Spyder(s). If you don't, then I would locate everything at Main panel 1, using MTU CTs for the feeds from/to the two subpanels and the utility feed, and Spyder CTs for any load circuits there you may want to monitor. If you decide you do want to monitor anything on the second main panel, I would put another MTU/CT set +/- a Spyder in it, but consider taking power to the MTU from the breaker in the first panel that you are using for the other MTUs. That way, you should minimize the risk of PLC problems between the MTUs and your ECC.