Author Topic: Ted Pro Home with multiple MTUs  (Read 1722 times)

pbretton

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Ted Pro Home with multiple MTUs
« on: March 17, 2015, 11:12:08 PM »
I have a question on the software configuration...  If I have a Ted Pro Home with 2 MTUs specifically because I have 3 spyders and one panel, do I set both MTUs as "NET" or is one "Stand alone"?  I'm not sure if that will skew the numbers or not by having both as "NET".

I'm sure I have more questions but that's the first one. 

Thanks in advance!

Piedmont

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Re: Ted Pro Home with multiple MTUs
« Reply #1 on: March 18, 2015, 02:19:31 AM »
Good question.  

It depends if you connected the 2nd MTU to anything using the 200A connectors.  Also keep in mind the Spyders don't actually do anything to the totals, or your current kWh/Hr, etc. Your spyder circuits are simply for informational purposes only and aren't as accurate as the MTU on your mains.  Sometimes if you add up what the spyders say they'll add up to say $0.20/kWh but your MTU will say you're using $0.18/kWh.  Spyders give you a ballpark estimate of the legs they're measuring.

Scenario 1... you have the first MTU attached to the mains and you attach the 2nd MTU's 200A sensors to a subpanel.  If you set both to NET you will be double-dipping the sub panel because your MTU1 will include all power coming to your house AND add what MTU2 is measuring through its 200A sensors.  In this configuration, MTU1 should be set to NET and MTU2 should be set to Standalone (which prevents MTU1 from adding MTU2).

Take scenario 2.  You have the first MTU set to NET and the 2nd set to NET but don't actually connect MTU2's 200A sensors to anything... just have the 3 spyders (one connected to MTU2).  In this case, MTU1 will record all the power coming in, and add in what MTU2 is measuring through its 200A sensors which aren't connected so the MTU2 will not affect anything but you will have the ability to see Spyders attached.

Take scenario 3.  You have the first MTU set to NET and the 2nd set to Stand Alone but don't connect the 200A sensors of MTU2 to anything.  Pretty much the same situation, MTU1 will measure all the power coming into the house, but it will keep MTU2's measurements separate which will be 0 because MTU2's 200A sensors aren't connected and you will have access to the spyder.  

In your case it doesn't matter if both are set to NET or MTU1 is set to NET and MTU2 set to Stand Alone IF MTU2's 200A sensors aren't connected to anything.  However, you may decide you want to connect MTU2's 200A sensors to something like a subpanel, or maybe without sensors some static is being detected on MTU2 sensor ports you should configure MTU1 as NET and MTU2 as Stand Alone.

In summary, it's best to configure MTU1 as NET and MTU2 as Stand Alone.  If you don't connect MTU2's 200A sensors setting both to NET will work but isn't as foolproof.
« Last Edit: March 18, 2015, 06:42:28 PM by Piedmont »