New Cbus Measurement Din Module.

Saw the Cbus Measurement device in the connected home MAG.

The way I think you have implemented this is Great. 4 Channel Great IDEA. Split Core Great IDEA (I assume they come with it) Much easier to install. What is the ETA on this

Looking forward to the Documentation.

I have given up waiting on the EN40P


Charles

 

Thanks

No, you buy each CT separately... i.e. Buy the Current Measurement Unit (CMU) as a part and the CT as a part. Both will be available at the same time

Expected to be available Q3

Will post the datasheet as soon as I can (just got back from CEDIA)

 

Shoul have gone to CEDIA Charlie - they had it on display there with the datasheets available as well. They ahd it running with the wiser widget and it looked great.

I was under the impresison though that it was available now. Q3 is not that far away though so it wont be long.

One question though, if I use this say on a small motor (lets say max 10A), and I have to use the 40A CT, how accurate will it be I am only using 1/4 the scale available.

Mick

 

If I understand correct this is a DIN rail C-Bus unit.
Has nothing to do with the Wiser Home Energy Management System that is available in US.
Is there at least a link for the "connected home MAG" to have a glance of this new product?

 

Datasheet attached

 

Any idea of RRP as yet? Also the CT transformers, assume they are similar to / slightly more than the Cent-A-Meter current sensors pricing?

 

CMU is expected to be about $200 +GST
CT's are expected to be about $25 +GST (each)

 

It the unit smart enought to know which way the current is flowing

If you have unit measuing the Main Cable into the property and the property has a SOLAR system and can back feed the grid
is the unit smart enought to know which way the current is flowing ?

Will wiser handle this when the current goes the other way.


Q3 is only 3 days away.... or is it the end of Q3 ??

 

No, you would need to put a CT on both incoming and outgoing separately.

Good question... I don't think so (just had a quick look), but i might be wrong... I have been wrong once before. Oh wait a minute, no i'm wrong, i wasn't wrong that time.

q3...

 

Can we fix this in version 2?

So are you saying you need to put two CT on the same cable
do these CT have an arrow on them indicating direction of the current they measure. do they measure 0 when the current goes the other way

So the answer is NO ? the graph it will produce will be consumption when it is not ? or will they go to 0

Are we going to address this

Charles

 

The current measurement unit measures current the same way a clamp-on type ammeter does. Consequences of this are:
1) only the ac component of current can be measured. dc current in the wire passing through the clamp will not contribute to the current level reported.
2)phase information between the current and voltage waveforms is not known, so direction of power flow in the wire can not be determined
3) there is no polarity on the current clamp. Ac current flowing either direction will display the same, and there is no way for the meter to determine the direction of current flow.
3) power flow can be estimated accurately only with knowledge of the mains voltage and load power factor

For your solar panel feed measurement, if you put separate clamp-on CTs:

a) between solar panel inverter and grid connection, and
b) between power meter and the loads, you should be able to work out what you're after.

 

Thanks don that makes sence I keep thinking DC when it is AC.

how does my meter know which way the current is flowing !

My cent-e-meter does not !

 

Does Tool Kit 1.11.8 mean that the

Measurement SENCT4 is going to released for sale ?

There are 9 days of Q3 left

Charles

 

Yes

 

Dealing with Solar Panels

I have been trying out the new current sensors and it took me a little while to work out how to deal with solar panels. In my house, the power from the grid (P in the diagram below) joins the power from the solar panel (S) at a point which is not accessible.

View attachment SolarFeedIn2.bmp

It the diagram C is the power consumed by the house.

Using Kirchhoff's Current Law, we know that:

C = P + S

So we can indirectly measure C by putting a current clamp around P and S as shown. Because C is always positive, P + S is also always positive and we don't need to worry about current direction.

Similarly, S is always positive.

P can be negative if S > C, but it doesn't matter since we are not measuring P by itself.

Then in PICED, you can add the two Measurement Application channels for the two current sensors, but set the one measuring S to not be included in the totals (since the other current clamp is measuring the total C).

I hope this makes sense. It took a while to convince myself that this was correct, and testing since then confirms that it works.

 

Thank you darren for posting this.

This is exactly what I was thinking but was not sure is PICED would cope

Going to order my modules. Just having issues getting partnumbers for the current clamps

 

Can you please post the Install documents.

I assume this have the part numbers for the current clamps

Can not see it here

http://www2.clipsal.com/cis/technical/literature/installation_instructions/input_units

and the Datasheet does not have it.

 

Makes sense, Darren.

I my case I had full access to P, C and S, so one channel does C directly, measuring actual power consumed by house (always positive) and another channel does S directly, measuring power from solar panels (always positive). The measurement channel S is marked as a generator in PICED so the nett consumption is simply the combination of these two measurement channels. The absolute value of P is not measured, nor would it be helpful anyway, as CT's cannot determine the direction of current flow, as P is negative whenever S is greater than C.

The remaining measurement channels are used for measuring specific circuits of interest but are flagged not to be included in any totals in PICED.