Setup for 3Phase Monitoring - Continued from eMonCMS Community Forum

OK, so the hot water is designated as phase C, yet the pf is .49. The cosine of 120° is .50, so that’s no doubt not on phase C. While it is running, try changing the phase to A and B. When you get it right, the pf will be .99 or 1.00 and the watts should go to about 3000.
If the “reversed” symbol precedes the input when it is 3000 watts, you can safely assume that it is.
When we know which it is, you may be able to sort it out using the color of the conductors, if the electrician who wired it observed a convention.

OK, let’s see what happens when you start the clothes dryer.

Ummm. Just realised that internal house stuff may not be super useful as I don’t have any monitoring on house circuits. (We ran out of inputs on the IotaWatt.)

I did fire it up and screenshot attached but its attached to house. Will also keep an eye on the hot water as it kicks in. I had picked circuit C as that was the “Mains” input I could see that was supplying the load.

EG Dryer appears to be on Mains1/A

EDIT:
As an FYI, the shed monitors go to a seperate older board. It appears to have lighting, power and pool pump hanging of the circuits for it. Ditto for the garage so it will be possible to generate a load and observe. The house ultimately is less of an issue for me but I can move CTs around across the circuits if you need me to try this for phase troubleshooting

Let me know at whatever level works for you. I can organise an Electrician if needed or will stop you when over my head.

Could you plug the hair dryer into the same outlet as the VT and see how the mains change. It’s important to determine that.

Are are 2 screen shots.

Hair Dryer ON

Hair Dryer OFF

Hair Dryer ON (With no Hotwater)

EDIT
Added Hair Dryer ON with no Hotwater ON as I realised it may affect trouble shooting
Hair Dryer is labelled as 1800watts but…

It looks as if the VT is on phase A. Not sure about the 1800 watts vs ~1300, but pf 1.00 indicates the correct phase.

Im curious why the hot water is now 3000watts with pf 1.00. Did you change that to phase B?

I agree that VT is on Phase A.

I changed Hot Water to Phase B as when it kicked in, Mains B spiked in conjunction so I made assumption it was B.

Let me know what you want me to do next.

I will get you photos of the boards I am dealing with tomorrow when I have some light.
One has been updated a little and 2 are pretty old.

It does appear to be on B. From the previous experiment it also seems to be on main3, so I think main3 should also be phase B and by elimination, main2 should probably be phase C.

With the mains properly labeled, you may be able to determine which main is associated with each of the remaining circuits, and assign them to the same phase as their associated main. This is where you may find that the various feeds to shed, garage, and AC are color coded by phase.

Of particular interest will be the solar, because the main associated with that should have “allow negative values” checked so that it can properly track exported power.

For the benefit of anyone reading this to understand the logic, I misspoke here. What I meant to say was that it looks like the VT is on main1.

With this derived reference method, the VT is always on phase A by definition. That is to say that the definition of phase A is the phase where the VT is located.

The phases had been assigned to the mains somewhat arbitrarily as a starting point, and as it happens, main1 was assigned phase A and the plug for the VT is on the main1 circuit.

Note that main2 and main3 were also arbitrarily assigned to phases B and C respectively, but those turned out to be incorrect and it was actually C and B respectively.

The notion of numbered circuits 1, 2, 3 and phases labeled A, B, and C are arbitrary labels, and does not necessarily indicate any ordinal relationship between circuit and phase. That must be determined by observation, or tracing circuits, or some other method of deduction.

Once determined, it is possible to sort it out and establish that ordinal relationship by moving the CTs. In this case that would involve swapping the CTs in inputs 2 and 3, and reassigning the phases 2=B, 3=C.

Or not, you can just leave it as it is recognizing that phase is just a new attribute of the circuit and doesn’t need to have any ordinal relationship to the names.

I have updated Main3 to Phase B and Main2 to Phase C as suggested. This then gave me the following results which may mean I need to reverse the CTs?

Solar was already set to allow negative and we have some sun so we should be able to get some readings soon. (Picture below of Solar generation as of 9.44 this morning. I think there is something else I need to tweak with solar as it thinks I am making 44 watts or so during the night so I think it might be reading a little high at present)

I will post some pictures of the board as I am assuming that

With the mains properly labeled

you mean with the configuration we have done vs any clues left by the installing electrician???

UPDATE: Added a picture with some solar happening

Here are some photos of the electrical boards I have inherited on this property. Once I get a handle on things and some spare cash, I may upgrade but at present its a low priority due to cost.

Originally built in 1974? and the Garage and Shed boards are still original.
I believe that the solar was installed in 2007 and included a refresh to the main board.

The wiring is still pretty much original behind the boards. (eg red/black/green which is old for australia and no color coding for the phases).
CTs are all installed behind the main board which hinges and is an external metal box (typical for Australian)

Main Board

Garage
(workshop power/lights/sauna/fridges/etc)

Shed
(only the pool is connected these days - no boiler/compressor)

That equipment is completely foreign to me. The interconnecting wires are not visible and I can’t see where any of the CTs are placed. Not looking for more pictures, just saying I don’t think that will help.

What does seem to be useful is the newer breakers for garage, ac, shed and hw. I don’t see any reason why those should not be wired the same left to right, so if the CTs on those are in order, the phases should correspond the same.

That said, I don’t think we have the mains right yet. The CTs on those incoming cables should all be oriented the same way. Is that the case? I’m thinking it could be that main3 is phase C, and the CT is reversed. There are a lot of combinations of phase and CT orientation, and the effects of erroneous combinations can be similar.

So can you check the orientation of those CTs?

If I were there on the ground, I could probably figure it out in an hour. Halfway around the world, might take a week.

All good and I can get you photos of CTs if you want but I don’t think it will help. Just a matter of slow and steady trouble shooting.

I have checked the Phase 3 Main CTs.
Phase A and Phase C have the CTs in the same orientation.
Phase B has the CT in reverse.

I assume I should change Phase B to be the same as the A and C

As I understand it, the assignments are currently:
Main1: phase A
Main2; phase C
Main3: phase B

Just to be clear, are you saying that the CT on main3 appears to be oriented differently from the those on main1 and main2?

On the inputs to the board
Input 1 assigned to Phase A
Input 2 assigned to Phase C
Input 3 assigned to Phase B

CT for Input2 is reversed when compared to the other inputs.

Will post a photo.

If it helps for trouble shooting we can plug / unplug whatever you need to determine stuff

Front (Left to Right: Phase A Phase B Phase C)

Rear (Right to Left: Phase A Phase B Phase C)

(Note that the CT for Phase B is actually on the far left and as you can see its backwards compared to the other 2)

Can’t really see the full picture. Those big fuses have two leads, but it’s not clear which are connected to the supply, and which go to the load. Can you verify that all of the CTs are clamped to the supply, or all are clamped to the load? Because they go one way on the supply side and the other on the load side. The current flows into the hole for the supply, and out of the hole for the load.

Do you have a fire extinguisher?

We have a fire extinguisher.
I will swap the CT for Input2 which is currently mapped to Phase C

  • it had been around the other way anyways originally and was only swapped as we saw negative… Our mistake. Will try and get a better shot but its tough as the board is mounted and swings and there isn’t much play…