CTs on 240V Circuits

[sub3marathonman]

I know it has been mentioned a few times in various places, but I was still wondering and hoping to maybe clarify things a bit more here.

I understand that somehow the Water Heater, even though it is 240V, can be monitored accurately with one CT. I don't really know why, but that is what has been said.

Now other 240V circuits, if it isn't a "balanced load" must be monitored by two CTs. I can understand that, since it is two separate legs using two separate amounts of electricity. I see that the stove powers the little panel from one leg, which thus throws the "balanced load" off.

But are there any other special circuits that can be monitored with just the one CT that are "balanced loads?"

And the final question I was wondering about is if it is at all possible to somehow bend the wire in the circuit such that one leg is going one direction, the other leg is going the other direction, and then both of them through the one CT. And maybe that would completely throw off the beautiful wiring job the professional electrician did here? Most of them don't leave a spare inch of wire either, which has always upset me, since the cut is just wasted anyway.

I just see those 240V circuits with two CTs and keep wishing I could get away with one.

[Teken]

I know it has been mentioned a few times in various places, but I was still wondering and hoping to maybe clarify things a bit more here.

I understand that somehow the Water Heater, even though it is 240V, can be monitored accurately with one CT. I don't really know why, but that is what has been said.

Now other 240V circuits, if it isn't a "balanced load" must be monitored by two CTs. I can understand that, since it is two separate legs using two separate amounts of electricity. I see that the stove powers the little panel from one leg, which thus throws the "balanced load" off.

But are there any other special circuits that can be monitored with just the one CT that are "balanced loads?"

And the final question I was wondering about is if it is at all possible to somehow bend the wire in the circuit such that one leg is going one direction, the other leg is going the other direction, and then both of them through the one CT. And maybe that would completely throw off the beautiful wiring job the professional electrician did here? Most of them don't leave a spare inch of wire either, which has always upset me, since the cut is just wasted anyway.

I just see those 240V circuits with two CTs and keep wishing I could get away with one.

Some balanced loads which you mentioned are HWT, Base Board Heater, Dryer, Well Pump. You could simply perform a quick test on what ever 240 load you believe could use one single CT and use the GEM's software to see if the current method of measuring with two CT's is fairly accurate when compared to using one CT and software emulation.

[sub3marathonman]

Some balanced loads which you mentioned are HWT, Base Board Heater, Dryer, Well Pump. You could simply perform a quick test on what ever 240 load you believe could use one single CT and use the GEM's software to see if the current method of measuring with two CT's is fairly accurate when compared to using one CT and software emulation.

Yes, I can see that would work, but I could only do that after I purchased everything and had it set up. I was hoping a bit to not have to order and install a few CTs.

Also, ben had mentioned that the dryer would need two CTs.

As you have a most impressive setup Teken, I'm wondering what your thoughts are about just one CT on a 240V circuit. Have you found things usually balanced, or is there enough of a discrepancy to warrant the bit of extra work?

Thanks.

[Teken]

Some balanced loads which you mentioned are HWT, Base Board Heater, Dryer, Well Pump. You could simply perform a quick test on what ever 240 load you believe could use one single CT and use the GEM's software to see if the current method of measuring with two CT's is fairly accurate when compared to using one CT and software emulation.

Yes, I can see that would work, but I could only do that after I purchased everything and had it set up. I was hoping a bit to not have to order and install a few CTs.

Also, ben had mentioned that the dryer would need two CTs.

As you have a most impressive setup Teken, I'm wondering what your thoughts are about just one CT on a 240V circuit. Have you found things usually balanced, or is there enough of a discrepancy to warrant the bit of extra work?

Thanks.

I would offer to you that given the very low price of the CT's found in the Brultech store. You really can't go wrong in ordering enough CT's for each 240 load(s) you have in your home. For the balanced loads in my home I honestly did not see a huge difference that would sway me to use two CT's.

But, each person and environment will dictate what you ultimately go with.

If absolute accuracy is the goal then use two CT's and know moving forward what you see, is what you get! Right now there is a sale on the WiFi only GEM modules and if you bundle it up with the CT package you will be ahead in terms of savings.

We all look forward to seeing your install once you purchase a GEM system. Should you have any setup or configuration questions please do post them up.

[ben]

Anything with a motor will be unbalanced (look up inductive household loads, probably can find a bunch of examples).

I'm not sure if the use of 2 CTs on a balanced load would reduce error or increase error. The CTs have some inherit error, now you have possible error from 2 sources instead of 1 when using 2 CTs.