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 on: March 30, 2018, 12:35:57 PM 
Started by chabotd - Last post by pfletch101
Most PV strings (the ones I have, anyway) are designed for max 20A double pole breakers. If your PV input never exceeds 20 amps I don't see why using 20A CT's wouldn't work. - FWIW

The issue is not whether the current exceeds the rating of the CT, but whether there are 20A CTs that are compatible with the TED MTUs (as opposed to the Spyder unit). Plugging a 20A CT intended for use on a Spyder into a MTU CT input is (at the very least) likely to result in calibration problems.

 on: March 29, 2018, 06:18:11 PM 
Started by chabotd - Last post by Joacchim
Most PV strings (the ones I have, anyway) are designed for max 20A double pole breakers. If your PV input never exceeds 20 amps I don't see why using 20A CT's wouldn't work. - FWIW

 on: March 27, 2018, 02:23:13 PM 
Started by GH - Last post by GH
Posting the resolution, I swapped things out one by one and it turned out to be a bad MTU, bad in that it was returning inaccurate (way too high) spyder readings.

During the troubleshooting I learned that the latching split-collar and squeeze-type split-collar 200A CTs are calibrated differently, and MTU's with serial number 17xxxyy are set up to use the squeeze-type.  If you use a latching-type 200A CT instead the calibration factor is 2.61 (Ted Pro /Advanced/Modify MTU Calibration.

Thanks to David in support.

 on: March 26, 2018, 07:11:57 PM 
Started by GH - Last post by GH
Thank you both for the replies.  I will recheck orientation and closure as you suggest.  There is generation involved, I am "sure" it comes in before the main panel so will recheck that as well.

Graph attached showing the circa 5x difference and generally parallel movement.

If the rechecks come up dry I will open a support ticket.

Thanks again.

 on: March 26, 2018, 03:26:09 PM 
Started by GH - Last post by Support7
You will have to give me exact readings to be able to judge the "5x" difference better but key differences in the MTU and Spyder that need to be noted when comparing them on the same circuit are:
MTU is rated at +/-2% while the Spyder is rated at +/-7% so that may explain some of the difference.
MTU samples readings thousands of times a second to give you the average of that second while the Spyder samples thousands of times a minute to give the average of the minute so that will explain some differences in readings as well.
Also the Spyder and the MTU handle the data differently when calculating the readings based on certain things like power factor and kva so realtime readings may not seem similar but the averages work out over time. Smaller loads will also affect the accuracy of readings between the 400A and 200A CT's so if your measuring less than 500w with the 200A CT with the Spyder than there is a drop off point.

Spyder Specs:
Spyder vs MTU:

Hope that helps but yeah for troubleshooting if it's outside of the +/-9% difference (MTU 2% and Spyder 7%) than you will need to submit a support ticket

Support Ticket:

 on: March 26, 2018, 02:38:50 PM 
Started by GH - Last post by pfletch101
Things to check:
Are all the CTs properly closed round their respective wires?
Are the two MTU CTs oriented in the same way (red dots on both either towards or away from the breaker)?
Is there generation involved - can the direction of power flux through the breaker reverse under any reasonably likely circumstances? This will cause trouble because Spyder channels assume unidirectional flux.
Unless these checks bring up anything, you should probably raise a ticket on the main site. TED people are here quite frequently, but not necessarily every day. In my experience, tickets are responded to very promptly - usually within 24 hours. There have been some recent hardware changes requiring significant calibration corrections to be used for at least some combinations of CTs and ECCs.

 on: March 26, 2018, 02:11:41 PM 
Started by Tanjun - Last post by Tanjun
Hi all,

I'm in the process of updating firmware for both Footprints and Gateway and am curious to see changes that have occurred ahead of doing so. Does anyone have a change-log they could share with me for both items?

Current Footprints:   Footprints-20110608-R240.bin
Proposed Footprints: Footprints-20120531-R281.bin

Current Gateway:     Gateway-g-20110629-r452.bin
Proposed Gateway:   Gateway-g-20120530-r499.bin

Thanks in advance.

 on: March 26, 2018, 10:44:29 AM 
Started by GH - Last post by GH
To troubleshoot a new TED installation I have two pairs of CTs on one pair of wires coming out of a double breaker.  One CT pair is 400A split collar routed to the MTU and the other CT pair is 200A split collar routed to a spyder that is attached to that MTU.  Spyder settings combine those two CTs (ports 1 and 2).

The MTU pair and the Spyder pair give very different energy readings, Spyder is circa 5x larger and they move roughly in parallel but it varies a bit.  MTU Skp is less than 5%.

Any known issues that come to mind?  Is there a calibration setting required for the 400A CTs?

 on: March 14, 2018, 10:51:59 PM 
Started by breaker man - Last post by pfletch101
Net, Gen (where relevant), Load, and MTU History values are taken or derived from MTU data. Spyder data is only involved if you are displaying history results for a specific Spyder.

 on: March 14, 2018, 08:24:57 PM 
Started by breaker man - Last post by breaker man
When looking at the History Tab I am assuming when your viewing the Net information the totals are coming from the MTU as opposed to spyders when your looking at spyders led  Is the correct?

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