Questions for new system

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ian351c
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Questions for new system

Post by ian351c » Wed Sep 09, 2015 3:51 pm

I'm planning on buying a GEM soon. I'd like to make sure I've got the right list of bits and pieces before I make the purchase...

First, here's what I know about my current panel and my goals for monitoring:

I have a 40 circuit panel in the house basement and an 12 circuit sub panel in the garage. I don't plan on monitoring the sub panel, so we can leave that out for now. The main panel has (I think) 200 Amp service. It's got what appear to be 4 breakers tied together, each labeled "200" and behind the panel cover, there are two very thick cables going to this assembly. I've read that this probably means I have 200 Amp service with each half of the main panel being served 100 Amps. The circuits in the main panel are a mix of mostly 15 and 20 Amp single pole circuit breakers. These are pretty easy and I've already decided which ones I will monitor with a single CT. Together, I can cover these with 25 CT-50s. There are also 5 double pole breakers of various amperages (40, 40, 30, 30 and 20). Here's where I get confused. I'm hoping that I can monitor each of these circuits with a singe CT-50, but I'm not quite sure about the wiring. Two of the circuits are fairly easy: they each have a red and a black wire screwed to the breaker and nothing else (they go to the oven and my septic pump). There is a white wire for each of these circuits going to the bus bar. The remaining 240V DP breakers are wired thusly:

1) Two black wires going to the breaker, labeled "1" and "2". Also two bare wires going to bus bar. Very large wires, 8 gauge or so. This is the 40 Amp service to the garage.

2) Two black wires going to the breaker, no labels. Also a white wire going to the bus bar. Larger than a "regular" 12-14 gauge wire. Call it 10 gauge. This is 30 Amps to the A/C Compressor.

3) One black, one white wire going to the breaker, no labels. Bare wire going to bus bar. This appears to be a regular 12 gauge sheathed cable. This is 30 Amps to the clothes dryer.

I think these are all considered "balanced" (except maybe the service to the garage panel). But I'm not sure....

Either way, my BOM looks like this (I think):

1x GEM
2x Split-100 CT (+ 1 spare)
30x Micro-50 CT (+2 spare)

Does that all sound right?

Thanks!

Ian
ben
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Re: Questions for new system

Post by ben » Thu Sep 10, 2015 11:18 am

Those 3 all sound like unbalanced loads so you'd need to monitor them with 2 CTs each.

If there's no neutral, it's a balanced load.
Ben
Brultech Research Inc.
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ian351c
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Joined: Wed Sep 09, 2015 2:26 pm

Re: Questions for new system

Post by ian351c » Thu Sep 10, 2015 2:06 pm

So, would that make the other two unbalanced as well? They have each have a wire going to the bus bar as well as the two to the breaker... I also read that as long as the load is a single appliance (A/C compressor, oven, etc.) that the load is balanced no matter how many wires there are. The exception being a mixed voltage use: the oven light/display or something like that).

Thanks.

Ian
Teken
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Re: Questions for new system

Post by Teken » Thu Sep 10, 2015 2:18 pm

Hello Ian,

Can you upload a picture so there is no guessing what is being described?




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ian351c
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Re: Questions for new system

Post by ian351c » Thu Sep 10, 2015 3:27 pm

Absolutely! :)

I annotated them, so hopefully they are self explanatory.
Oven and Septic
Oven and Septic
240V-1-2.jpg (2.21 MiB) Viewed 5033 times
Dryer and AC
Dryer and AC
240V-3-4.jpg (2.6 MiB) Viewed 5033 times
Garage
Garage
240V-5.jpg (2.42 MiB) Viewed 5033 times
Teken
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Re: Questions for new system

Post by Teken » Fri Sep 11, 2015 9:23 am

Hello Ian,

Based on the photo alone they all appear to be a balanced load with out a neutral. With out being there physically its hard to say with 100% accuracy though. The worst case is if you're wrong you only need to add in a second CT to monitor the other side.

For your reference there really isn't a right or wrong when using 1 / 2 CT's to monitor a balanced load. It comes down to preference and the level of accuracy you're after.

I've found that the GEM's software doubling feature is extremely accurate though. It should be noted that in general terms a *balanced load* should be the same watts consumed. In reality depending upon what the load / appliance is it could be very different.

Case in point my electric hot water tank has the common top & bottom elements. I found that the top element was actually consuming more than the bottom one. I would not have known this if I was strictly using 1 CT to monitor the circuit.

In 95% of the other cases even when I used 2 CT's to monitor a balanced load it was the same for both sides of the electrical feed. I would humbly suggest you use 2 CT's on any suspect 240 circuit and compare it to the GEM's software doubling feature.

If you find no difference you just saved yourself some cash on a CT. If they are different then you have complete accuracy and can sleep better knowing what ever you see is 100% accurate from the onset.

Please keep in mind the following: The GEM system is a long term investment and in the big picture you are only going to do this once. Might as well spend the extra money on ALL the CT's you need.

Because a year down the line you won't even remember you spent that extra $25-85.XX for those extra's which in the big picture simply just works!
Teken . . .

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ian351c
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Joined: Wed Sep 09, 2015 2:26 pm

Re: Questions for new system

Post by ian351c » Fri Sep 11, 2015 12:46 pm

I'm OK spending the money on the CTs. My problem is that I've got a 40 circuit panel that is completely full. I'll be using two channels on the GEM to monitor the house service, which leaves me with 30 channels to monitor 35 circuits (40 slots minus the 5 double-slot breakers). If I have to monitor both sides of those 240V circuits, then I'm up to 42 channels total.

What do my options look like at this point? Let's assume two scenarios: 1) I only want to buy a single monitor (the GEM). or 2) I want to monitor all 42 channels (however many monitors that takes).

Thanks.

Ian
Teken
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Re: Questions for new system

Post by Teken » Fri Sep 11, 2015 1:18 pm

ian351c wrote:I'm OK spending the money on the CTs. My problem is that I've got a 40 circuit panel that is completely full. I'll be using two channels on the GEM to monitor the house service, which leaves me with 30 channels to monitor 35 circuits (40 slots minus the 5 double-slot breakers). If I have to monitor both sides of those 240V circuits, then I'm up to 42 channels total.

What do my options look like at this point? Let's assume two scenarios: 1) I only want to buy a single monitor (the GEM). or 2) I want to monitor all 42 channels (however many monitors that takes).

Thanks.

Ian
Hello Ian,

Please note you can monitor both electrical main feeds with just one channel. The only reason I monitor both sides separately using two channels is because it allows me to see and monitor my solar NET energy and both sides of the homes electrical loads independently.

Its safe to say 90% of the users wire both 100 / 200 Split CT's and wire them into a single GEM channel. The remaining 10% do it my way for reasons I listed above or have other use cases.

As noted, when you're using two CT's to monitor a 240 balanced load it only occupies one channel. Also, any rarely used circuits can be combined into other channels but you must ensure you properly secure the wire bundle to a single 2 pair wire so as to not damage the GEM's PJ terminal block.
Teken . . .

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ian351c
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Joined: Wed Sep 09, 2015 2:26 pm

Re: Questions for new system

Post by ian351c » Fri Sep 11, 2015 3:27 pm

Ah.... So when you "double up" on a monitor, it's not at the circuit breaker panel, it's at the terminal block! I learn something every day! :-)

In that case, I'll just slap CTs on all the circuits and start with a single GEM. I can expand later if I really feel the need to monitor all the CTs individually.

For future reference, what is the best way to expand? Can you add a 1240 (or multiple 1240s) to a GEM?

Thanks.

Ian
Teken
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Re: Questions for new system

Post by Teken » Fri Sep 11, 2015 4:45 pm

Hello Ian,

There is nothing stopping you from buying another GEM or the ECM-1240 per say.

But it should be noted the ECM-1240 is no longer being developed. In the long run the GEM will continue to offer much more to the end user in terms of features and support.

Should you wish to monitor both types via the hardware dash box. The DB supports two ECM's and one GEM.

Again please consider this purchase as an investment and not a final product.

As Brultech continues to lead the energy monitoring space with never ending development, features, and a open attitude toward user feedback.




Ideals are peaceful - History is violent
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
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