Unbalanced mains?

Support
1

I have an Iotawatt and a TED5000 both recording on my L1 and L2 utility mains coming in, just to validate each other for now. I also have 2 solar inverters feeding the panel, but I have those disconnected until I figure out what is going on.

The Iotawatt shows 1200W on L1 and -300W on L2. The Ted5000 shows 900W total (it doesn’t break out individual CTs). So they appear to be in agreement, but why the negative power on L2? The arrows on my Iotawatt CTs are opposite, but I have L2 marked as reversed to adjust. The TED5000 CTs are both pointing the same way.

Can I really be pushing power out on L2 when I have no generation happening?

2

No, not if you have a 120V/240V split-phase service.

1 Like
3

Figured it out (I think). Found deep in the docs that the L2 CT needs to be reversed because the 9VAC reference transformer is on L1. Gaah

4

That explains the negative L2, but now you have 1,500 Watts total vs the Ted 900W. Pretty sure the two will agree if they are both correctly configured. Fortunately you have the meter as an arbiter.