Author Topic: CT size  (Read 1819 times)

SteveT

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CT size
« on: April 24, 2017, 03:40:30 PM »
1.) I'm getting ready to pull the trigger on the HomePro. I have solar so will need another MTU. My question is, and sorry if it's been addressed before, the solar breaker is 20 amp. Trying to save $$$ so thinking of the MTU and 2-60A DONUT CT. Will this work? having a hard time with needing 200amp CT on a 20 amp breaker but if I have to have that then C'est la vie.

2.) Now, on the ordering page you have to select copper or Aluminum feeds. Seems there is a size difference? Mine look aluminium.

Thanks

pfletch101

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Re: CT size
« Reply #1 on: April 25, 2017, 04:42:36 PM »
1.) I'm getting ready to pull the trigger on the HomePro. I have solar so will need another MTU. My question is, and sorry if it's been addressed before, the solar breaker is 20 amp. Trying to save $$$ so thinking of the MTU and 2-60A DONUT CT. Will this work? having a hard time with needing 200amp CT on a 20 amp breaker but if I have to have that then C'est la vie.
Thanks

The CTs have to be matched to the electronics they are talking to. AFAIK, the lowest current 'primary' CTs available are the standard 200A ones. Given the specs on the two CT types, too, you get almost the same absolute accuracy at 20A with the standard CTs as you would with the 60A ones, even if you could use them.
Peter R. Fletcher
TED Pro Home - main MTUs monitoring utility and PV Solar feeds; 2 Spyders monitoring selected individual circuits

pfletch101

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Re: CT size
« Reply #2 on: April 25, 2017, 04:49:11 PM »
2.) Now, on the ordering page you have to select copper or Aluminum feeds. Seems there is a size difference? Mine look aluminium.
Thanks

If you have a properly configured 200A service, the newer CTs, which are a reasonably snug fit around 200A rated copper cable, will not fit round similarly rated aluminum cable (aluminum is not quite as good a conductor as copper, so a cable with the same rating has to have a larger diameter). If the wires you are putting them round are rated at less than 200A, the smaller ('copper') ones should be fine.
Peter R. Fletcher
TED Pro Home - main MTUs monitoring utility and PV Solar feeds; 2 Spyders monitoring selected individual circuits

SteveT

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Re: CT size
« Reply #3 on: April 25, 2017, 07:22:52 PM »
Thanks all. I've place my order for
TED Pro Home with larger CT andTED Pro Home 200 Amp MTU/CT Add On Set
Thanks for the replys