How to determine CTs for your panel

[Teken]

Hello Ben,

About this:
===============
Special consideration:
- for 240V loads with no neutral – you can get away with monitoring 1 side of the breaker and doubling the rating,
===============

Do we have to double "manually" the rating, i.e. to remember that the Watts for this channel will need to be doubled, or is there a means in the software to apply automatically this x2 factor for the concerned channels before it is graphed ?

All electric baseboard heaters for example are 240V with no neutral, I intended to install a single CT on each.

I have received my GEM+Dashbox but did not install yet.

Brgds/Jerome

Once you are able to access the GEM setup page under the CT tab you will see the option to double the output. Once done there is nothing else for the user to do and the DB will reflect that information correctly.

[jtoutee]

Excellent ! Thanks a lot, Teken.

[sub3marathonman]

I have a question about monitoring the "Type A" (Split CT) circuits.

In the manual, it shows how to connect two Type A leads, one CT (#1) lead in terminal 1 and 2, and one CT (#2) lead in terminal 3 and 4.

I'm wondering if it is possible / acceptable to connect two Type A leads as two CT (#1 and #2) leads in terminal 1 and two CT (#1 and #2) leads in terminal 2.

And then further, connecting another two Type A CT (#3 and #4) leads similarly in terminal 3 and terminal 4, for a total of four Type A CTs monitored in a single channel.

Thanks for the help.

[ben]

I have a question about monitoring the "Type A" (Split CT) circuits.

In the manual, it shows how to connect two Type A leads, one CT (#1) lead in terminal 1 and 2, and one CT (#2) lead in terminal 3 and 4.

I'm wondering if it is possible / acceptable to connect two Type A leads as two CT (#1 and #2) leads in terminal 1 and two CT (#1 and #2) leads in terminal 2.

And then further, connecting another two Type A CT (#3 and #4) leads similarly in terminal 3 and terminal 4, for a total of four Type A CTs monitored in a single channel.

Thanks for the help.

You can, but they need to be connected in series to 1,2 and 3,4. Not parallel.

[sub3marathonman]

You can, but they need to be connected in series to 1,2 and 3,4. Not parallel.

OK, this must be more complicated than it sounds.

Here's what I'm trying to do: monitor two 240v circuits, A/C and A/H, on one channel. So each of the A/C lines has two Split-60s, and each of the two A/H lines has two Split-60s.

There is a limited way to hook the combinations up, but I haven't seen how to do it correctly.

I am starting with the A/H. I have monitored both wires separately, with 86w and 105w. They were monitored with an extension wire inserted into Channel #3 and Channel #4. Channel #1 and Channel #2 are unused at this point. (As a side note, the A/H readings seem extremely low, so I'm not sure they are accurate.) The channel was set up as a Split-60 in the setup webpage.

I have then connected both Split-60s up as White/White and Black/Black, and they cancelled out. So I reconnected both Split-60s up as White/Black and Black/White, and ended up with essentially the reading of a single Split-60 with 78w.

It was a similar story when I attempted to monitor just the A/C 240v circuit, either almost zero or what seems to be the reading of a single Split-60 CT.

This seems very similar to pmenkel's question here:
http://www.brultech.com/community/viewt ... =29&t=1332
but he's trying to monitor both the A/C and the dryer on separate circuits, and pmenkel is working with CT40s, not Split-60s.

[Teken]

You can, but they need to be connected in series to 1,2 and 3,4. Not parallel.

OK, this must be more complicated than it sounds.

Here's what I'm trying to do: monitor two 240v circuits, A/C and A/H, on one channel. So each of the A/C lines has two Split-60s, and each of the two A/H lines has two Split-60s.

There is a limited way to hook the combinations up, but I haven't seen how to do it correctly.

I am starting with the A/H. I have monitored both wires separately, with 86w and 105w. They were monitored with an extension wire inserted into Channel #3 and Channel #4. Channel #1 and Channel #2 are unused at this point. (As a side note, the A/H readings seem extremely low, so I'm not sure they are accurate.) The channel was set up as a Split-60 in the setup webpage.

I have then connected both Split-60s up as White/White and Black/Black, and they cancelled out. So I reconnected both Split-60s up as White/Black and Black/White, and ended up with essentially the reading of a single Split-60 with 78w.

It was a similar story when I attempted to monitor just the A/C 240v circuit, either almost zero or what seems to be the reading of a single Split-60 CT.

This seems very similar to pmenkel's question here:
http://www.brultech.com/community/viewt ... =29&t=1332
but he's trying to monitor both the A/C and the dryer on separate circuits, and pmenkel is working with CT40s, not Split-60s.

Hello,

I like to keep things simple as such can you place just (one) of the CT's on another circuit like an outlet you know of.

Take a hair dryer and let it run for two minutes. Please report back if this single split 60 CT registers the energy readings. If so disconnect the existing split 60 CT and insert the other one and perform the same action.

Both CT's should indicate within a margin of error the same wattage. If this proves successful please connect just one of the CT's to the AC.

What is the reading and what do you expect to see in terms of watts?

[sub3marathonman]

Hello,

I like to keep things simple as such can you place just (one) of the CT's on another circuit like an outlet you know of.

Take a hair dryer and let it run for two minutes. Please report back if this single split 60 CT registers the energy readings. If so disconnect the existing split 60 CT and insert the other one and perform the same action.

Both CT's should indicate within a margin of error the same wattage. If this proves successful please connect just one of the CT's to the AC.

What is the reading and what do you expect to see in terms of watts?

OK, connected one of the Split-60s to another circuit currently being monitored by a CT80, and getting essentially half the reading, which is what is expected, so the Split-60 is definitely accurate.

One Split-60 remains connected to the A/C circuit, and reads right about 1000w, which is also presumed accurate.

And, when connected as the manual states, both add together on the same channel for about 2000w.

My wish though is to monitor those two Split-60s, as set up now correctly, with an additional two Split-60s for the A/H, but on the same channel.

I am also understanding that it appears that this could be done by monitoring one A/C line and one A/H line, and doubling the reading, even though it is my understanding that these are circuits with a neutral and could thus possibly (but apparently not always) have uneven consumption between the two 120v legs. I didn't realize when I bought the CTs that the consumption would be so uniform, at least with these specific circuits, and now that I have them I figure I might as well use them.

[Teken]

Hello,

I like to keep things simple as such can you place just (one) of the CT's on another circuit like an outlet you know of.

Take a hair dryer and let it run for two minutes. Please report back if this single split 60 CT registers the energy readings. If so disconnect the existing split 60 CT and insert the other one and perform the same action.

Both CT's should indicate within a margin of error the same wattage. If this proves successful please connect just one of the CT's to the AC.

What is the reading and what do you expect to see in terms of watts?

OK, connected one of the Split-60s to another circuit currently being monitored by a CT80, and getting essentially half the reading, which is what is expected, so the Split-60 is definitely accurate.

One Split-60 remains connected to the A/C circuit, and reads right about 1000w, which is also presumed accurate.

And, when connected as the manual states, both add together on the same channel for about 2000w.

My wish though is to monitor those two Split-60s, as set up now correctly, with an additional two Split-60s for the A/H, but on the same channel.

I am also understanding that it appears that this could be done by monitoring one A/C line and one A/H line, and doubling the reading, even though it is my understanding that these are circuits with a neutral and could thus possibly (but apparently not always) have uneven consumption between the two 120v legs. I didn't realize when I bought the CTs that the consumption would be so uniform, at least with these specific circuits, and now that I have them I figure I might as well use them.

Circuits using a neutral should always be monitored with separate CT's. Even if the energy readings are very close using the doubling (software) feature is not the route to follow. You can certainly wire another two sets of CT's (exactly) the way you did with the other one's as outlined by Ben.

This would allow you to monitor the whole unit I suppose. I guess what I am not clear on is normally there is just a compressor / fan? What else is being monitored that is not captured by the other two CT's?

[sub3marathonman]

Circuits using a neutral should always be monitored with separate CT's. Even if the energy readings are very close using the doubling (software) feature is not the route to follow. You can certainly wire another two sets of CT's (exactly) the way you did with the other one's as outlined by Ben.

OK, so I've got the A/C monitored correctly with the two Split-60s (#1 & #2) on one channel (Ch1). I've got the A/H monitored correctly with two Split-60s (#3 & #4) on another channel.

In order to combine them all onto one channel, I will need to move the A/H Split-60s (#3 & #4) to the channel Ch1. It seems there are only two ways to do this, which it seems are either parallel or series. I think parallel is white Split-60 #3 to white Split-60 #1 and black Split-60 #3 to black Split-60 #1 (assuming each Split-60 is on the same polarity from the electrical panel).

It seems that I did this, but the reading stayed the same as if it was only one CT connected. I did it the opposite way and the reading was essentially cancelled and went to zero.

So I am either doing something wrong, or not doing something that needs to be done in order to have it correct, such as resetting a value on the setup webpage.

[Teken]

Circuits using a neutral should always be monitored with separate CT's. Even if the energy readings are very close using the doubling (software) feature is not the route to follow. You can certainly wire another two sets of CT's (exactly) the way you did with the other one's as outlined by Ben.

OK, so I've got the A/C monitored correctly with the two Split-60s (#1 & #2) on one channel (Ch1). I've got the A/H monitored correctly with two Split-60s (#3 & #4) on another channel.

In order to combine them all onto one channel, I will need to move the A/H Split-60s (#3 & #4) to the channel Ch1. It seems there are only two ways to do this, which it seems are either parallel or series. I think parallel is white Split-60 #3 to white Split-60 #1 and black Split-60 #3 to black Split-60 #1 (assuming each Split-60 is on the same polarity from the electrical panel).

It seems that I did this, but the reading stayed the same as if it was only one CT connected. I did it the opposite way and the reading was essentially cancelled and went to zero.

So I am either doing something wrong, or not doing something that needs to be done in order to have it correct, such as resetting a value on the setup webpage.

I understood from Ben's initial reply that in that configuration it would have to be wired in series .