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Author Topic: Spyder gives small numbers..
ecosang
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Posts: 1


« on: December 04, 2017, 12:53:19 AM »

Hello, I compared MTU measurement on main circuit with sum of spyder sub-circuits.
Ideally, the sum of spyder sub-circuits should be similar to the value of main circuit measured from MTU.
As can be seen 112.png, Spyder show 0 value in most of time. When there is large load in Spyder, there is number, but still it is too small compared to MTU.
My sub-circuit breakers are 20A. But I am using 60A CTs for Spyder. But, still I think the numbers on Spyders are too small.
Also, when I looked at the graph, there is time-lag in Spyder.
Do you guys have any suggestion for this case?
By the way, in this case,
1,2,3,4  are connected to 20A(120V) breakers.
(5,7) and (6,8) are connected to 20A(240V) circuits.

Thanks

 
« Last Edit: December 04, 2017, 12:55:16 AM by ecosang » Logged
Support7
Administrator
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Posts: 458


« Reply #1 on: December 04, 2017, 10:07:25 AM »

Hi ecosang,

Did you say you are using 60A CT's on 20A circuits? This may work but it will not pick up smaller loads so it can affect the precision as you have mentioned. The Spyders do lag behind the MTU as they are designed to report every 1 minute+ where as the MTU reports every 1 second+ so you do not get the real time data from the spyder as it is meant as a cost effective way to break down energy usage by circuit.

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
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pfletch101
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Posts: 418


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« Reply #2 on: December 04, 2017, 10:10:06 AM »

Hello, I compared MTU measurement on main circuit with sum of spyder sub-circuits.
Ideally, the sum of spyder sub-circuits should be similar to the value of main circuit measured from MTU.

This would, indeed, be ideal. However, Spyder channels read zero at a power flux/current at or below a minimum value that depends on their rating (this is well documented in their specs), so the sum of Spyder readings will almost inevitably be less than the total load shown by the Utility MTU. This will be exacerbated by using 60A CTs for <=20A circuits, since their channel readings drop to zero at a higher actual current.

Make sure, also, that the settings of Spyder channels monitoring one 'side' of 240V circuits reflect this (double the reading). If you are monitoring both 'sides', the settings can be left in their normal configuration, but you normally don't need to do this, since domestic 240V loads are generally symmetrical.
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Peter R. Fletcher
TED Pro Home - main MTUs monitoring utility and PV Solar feeds; 2 Spyders monitoring selected individual circuits
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