How to determine CTs for your panel

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sub3marathonman
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Joined: Fri Feb 11, 2011 9:32 am

Re: How to determine CTs for your panel

Post by sub3marathonman » Thu Apr 16, 2015 9:24 am

Teken wrote:[I understood from Ben's initial reply that in that configuration it would have to be wired in series .
Yes, that's right, I'd gotten it mixed up.

But either way, there's only two ways to connect them. Either white Split-60 #1 to white Split-60 #3 or white Split-60 #1 to Black Split-60 #3.

And one way they cancel, and the other way, which is what I can't figure out, is such that it registers the value not for both combined but for only one.

So it is as if 1-1 =0 when they cancel out, but 1+1=1 when they're combined. Which just can't be right.
Teken
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Re: How to determine CTs for your panel

Post by Teken » Thu Apr 16, 2015 9:26 am

sub3marathonman wrote:
Teken wrote:[I understood from Ben's initial reply that in that configuration it would have to be wired in series .
Yes, that's right, I'd gotten it mixed up.

But either way, there's only two ways to connect them. Either white Split-60 #1 to white Split-60 #3 or white Split-60 #1 to Black Split-60 #3.

And one way they cancel, and the other way, which is what I can't figure out, is such that it registers the value not for both combined but for only one.

So it is as if 1-1 =0 when they cancel out, but 1+1=1 when they're combined. Which just can't be right.
I want you to wire it in series following the diagram in the users manual. If the values look incorrect simply reverse the wires on the one CT and report back what your see.

There are a few things in the GEM that can be changed but I assume you haven't fooled around with them and hope they are in the default state. In one section is the option to change the polarity of a channel.

Another option is to make a channel a NET channel for solar, wind, hydro power. If you're sure the wires are installed correctly please toggle one of these options to see if it makes a difference.

There is no harm in doing this so long as you track your efforts and return any setting to its original state if it causes problems. I doubt the above will resolve the issue to be honest.
Teken . . .

My ongoing projects thread: http://www.brultech.com/community/viewt ... ?f=2&t=929
Buy me a cup of coffee: https://www.paypal.me/Teken https://gfinotify.com/ Discount Code: PC10
sub3marathonman
Posts: 95
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Re: How to determine CTs for your panel

Post by sub3marathonman » Thu Apr 16, 2015 9:48 am

Teken wrote: I want you to wire it in series following the diagram in the users manual. If the values look incorrect simply reverse the wires on the one CT and report back what your see.
OK, now the A/C is correctly monitored again. In series as the manual says. Using all four of the holes, Split-60 #1 in holes 1&2, and Split-60 #2 in holes 3&4.

Now, if I want to monitor two more Split-60s in the same channel, I'll need both Split-60#1 and Split-60 #2 combined into holes 1&2.

There are really only two ways I can see to do that, neither which seems to work.

If they are done wrong, they cancel. But if they are done seemingly correct, it only registers the value of one of the CTs, which is half the value when they are initially monitored correctly as set up following the manual.
Teken
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Re: How to determine CTs for your panel

Post by Teken » Thu Apr 16, 2015 10:04 am

sub3marathonman wrote:
Teken wrote: I want you to wire it in series following the diagram in the users manual. If the values look incorrect simply reverse the wires on the one CT and report back what your see.
OK, now the A/C is correctly monitored again. In series as the manual says. Using all four of the holes, Split-60 #1 in holes 1&2, and Split-60 #2 in holes 3&4.

Now, if I want to monitor two more Split-60s in the same channel, I'll need both Split-60#1 and Split-60 #2 combined into holes 1&2.

There are really only two ways I can see to do that, neither which seems to work.

If they are done wrong, they cancel. But if they are done seemingly correct, it only registers the value of one of the CTs, which is half the value when they are initially monitored correctly as set up following the manual.
I wanted to point out in case this was missed. If the CT at the breaker (assumed) is facing the correct position. Then you can safely wire the CT's into the PJ as described. If the CT is NOT installed correctly then your wiring will be opposite of what you expect.

This of course does not explain why the value appears to be incorrect (lower) when you reverse the wires.

Lets keep this simple moving forward because I didn't see you indicating it was done. I want you to use a known load. When I say a known load something that is accepted as being fairly accurate.

Take a 60, 100 watt incandescent bulb, and a hair dryer. Place the trouble CT's on what ever circuit you can monitor for this test.

Using just (1) of the CT's with the 60 wattt bulb it should be fairly close. If so change it out to the 100 bulbs. Again it should be pretty close, now use a 1500 watt hair dryer and on the low setting mark down what the wattage is.

Ramp it up to the high setting and mark down what the power output is. You will more than likely see a variance. If this the case the GEM has the ability to fine tune the CT values. Keep in mind if you make the changes on a channel its only for that channel so use caution.

This is only to confirm the CT's you have on hand are working and accurate with in their margin of 1-3% error rate.

Once you have tested all four CT's and report back their readings we will at least know they operate or not. If they operate than Ben will need to assist you in coming up with a solution to wire the 4 CT's assuming this can be done.

NOTE: What ever channel you decide to use must be changed to reflect the split 60 CT. If you perform this test and its programmed for a micro 40 the readings will be off.
Teken . . .

My ongoing projects thread: http://www.brultech.com/community/viewt ... ?f=2&t=929
Buy me a cup of coffee: https://www.paypal.me/Teken https://gfinotify.com/ Discount Code: PC10
sub3marathonman
Posts: 95
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Re: How to determine CTs for your panel

Post by sub3marathonman » Thu Apr 16, 2015 10:10 am

OK, I think I have gotten it figured out!!

You need to connect them in series just as Ben said and Teken reminded me. :D

The difficult thing for me was figuring out how to do that. Now I think I know.

On a terminal block, with the two Split-60s monitoring the A/C, I used four spaces. White, Black, Black, White when it was being monitored correctly as set up in the manual.

Now, needing to connect it in series, my mistake was attempting to connect the wires together as if they were Micro-CTs, which will always be parallel either correct polarity or incorrect polarity and cancelled to zero. But parallel correct is still just the voltage of one CT, which is why it was doing what I observed and giving the reading of one CT.

So, now leaving the wires in the terminal blocks, I disconnected the two extensions going to spaces 3 and 4 of the channel. I moved the wire going to space 2 to the location where the wire to space 4 was. I then put the jumper wire between the two CT leads (one + and one -).
DSC_9088.JPG
DSC_9088.JPG (2.65 MiB) Viewed 12952 times
And thus the CTs are connected in series.

(Note: It is the middle four wires in the terminal block.)

And Thanks Teken for the help today!!!
Last edited by sub3marathonman on Thu Apr 16, 2015 10:16 am, edited 1 time in total.
Teken
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Re: How to determine CTs for your panel

Post by Teken » Thu Apr 16, 2015 10:14 am

Good man fire up the AC and report success / failure! If everything works out please do document it in your install / project thread. As I am sure it will help someone else down the road.

Moving forward you should still perform the fine tuning portion to get the last bit of accuracy out of the system.
Teken . . .

My ongoing projects thread: http://www.brultech.com/community/viewt ... ?f=2&t=929
Buy me a cup of coffee: https://www.paypal.me/Teken https://gfinotify.com/ Discount Code: PC10
sub3marathonman
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Re: How to determine CTs for your panel

Post by sub3marathonman » Thu Apr 16, 2015 10:20 am

Teken wrote:Good man fire up the AC and report success / failure! If everything works out please do document it in your install / project thread. As I am sure it will help someone else down the road.

Moving forward you should still perform the fine tuning portion to get the last bit of accuracy out of the system.
Yes!!! It seems to work. But it does seem ever so slightly lower than what I was seeing when monitoring individually. I don't know if that is expected or if I've not made perfect connections between the wires.

I will eventually work on the fine tuning, but glaciers move slowly and that won't be for awhile. :roll:

Thanks again Teken for the help!
Teken
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Re: How to determine CTs for your panel

Post by Teken » Thu Apr 16, 2015 10:26 am

sub3marathonman wrote:
Teken wrote:Good man fire up the AC and report success / failure! If everything works out please do document it in your install / project thread. As I am sure it will help someone else down the road.

Moving forward you should still perform the fine tuning portion to get the last bit of accuracy out of the system.
Yes!!! It seems to work. But it does seem ever so slightly lower than what I was seeing when monitoring individually. I don't know if that is expected or if I've not made perfect connections between the wires.

I will eventually work on the fine tuning, but glaciers move slowly and that won't be for awhile. :roll:

Thanks again Teken for the help!

No worries, take your time and do it right the first go round. Rome wasn't built in a day so complete each step knowing its done correctly. The fine tuning is important to do as it impacts the high / low readings you ultimately see and measure.

Please note the first (fine tuning) should be to the PT transformer using a true RMS DMM. The measurement needs to be taken at the same outlet the PT is plugged into. This governs on a global scale how the GEM will interpret the energy readings entering the unit.

The next step is making the fine adjustments to the individual channels. There is one more fine tuning value but this must be directed by Brultech which is the current / amp value settings.

Do a quick search and you will find the thread with all the details
Teken . . .

My ongoing projects thread: http://www.brultech.com/community/viewt ... ?f=2&t=929
Buy me a cup of coffee: https://www.paypal.me/Teken https://gfinotify.com/ Discount Code: PC10
turbo
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Joined: Sat May 16, 2015 6:01 pm

Re: How to determine CTs for your panel

Post by turbo » Mon Jun 22, 2015 11:53 am

I'm thinking this answers a problem I'm having getting readings from 240V devices. I didn't know how test for a device having a neutral or not, or didn't really think it through. I have 6 240V breakers. 3 of them are showing readings (heat pump, furnace, dryer) while three aren't registering anything (two ranges, 1 water heater).

I set up the CT's with 1 CT on one leg of each 240V breaker set and turned on GEM Doubler. I'm thinking now I need to get a second CT on those three systems as they have a neutral.

The only other CT with no reading is the one for the GEM outlet. It oddly shows one spike for a few seconds and nothing else.
ben
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Re: How to determine CTs for your panel

Post by ben » Mon Jun 22, 2015 1:49 pm

turbo wrote:I'm thinking this answers a problem I'm having getting readings from 240V devices. I didn't know how test for a device having a neutral or not, or didn't really think it through. I have 6 240V breakers. 3 of them are showing readings (heat pump, furnace, dryer) while three aren't registering anything (two ranges, 1 water heater).

I set up the CT's with 1 CT on one leg of each 240V breaker set and turned on GEM Doubler. I'm thinking now I need to get a second CT on those three systems as they have a neutral.

The only other CT with no reading is the one for the GEM outlet. It oddly shows one spike for a few seconds and nothing else.
The ones with no reading, do you have multiple CTs connected to that channel? If so, it's possible they're cancelling from each other. You can try reversing one set of leads.
Ben
Brultech Research Inc.
E: ben(at)brultech.com
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