System design

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agr077
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Joined: Tue Jan 14, 2014 3:31 pm

System design

Post by agr077 » Thu Mar 05, 2015 4:17 pm

Looking for some advice and/or confirmation that the system design I am looking at makes sense and I am not making any errors in what I will be purchasing. I’ll be having an electrician do the installation and I’d like it to be a job done in one trip.

Picture of my electrical panel and an excel file that lays out the design I am envisioning. What I am most concerned about are the following:
  • - Choice between micro 40/micro 50 and micro 80/micro 100. I am inferring from the information on the product website that the 50/100 are more accurate but slightly larger than their counterparts 40/80. Is that really the case and should I care about the accuracy? Are there other reasons to go for the 50/100? The incremental cost is minor given I would only do so for loads that are higher use and therefore I’d care about the accuracy more. Are there are other reasons to consider them that could also sway me in wanting to use 50/100 in more places?
    - One consideration that I have to take into account with the 50/100 vs. 40/80 is the size relative to my panel. I have attached a picture of my panel. Does anyone have a POV on whether I could even fit the larger ones in a few or many spots or will the panel get too full?
    - Regardless of the above choice is the rest of the design correct? In particular, where I have dual breakers (no idea if that is the correct terminology), like for the stove which is 2 x 40amp loads, I should be putting 2 micro 40s or 50s. is that correct or are there other considerations to take into account?
    - Based on the design, do I have the right number of CTs
    - Because the GEM has 32 channels I have made some choices about which breakers get their own channel and which will be combined. My methodology was based on higher/regular use breakers being separate and lower/intermittent use breakers being combined. Interested if anyone has any feedback and/or suggestions of how else they might do it if my current method isn’t optimal.
Separately, if anyone in the Toronto area has used a licensed electrician to install one of these systems and could make a recommendation that would be appreciated. I just need the install work in the panel done (I am very comfortable doing the connection and setup of the GEM and dashbox etc…).
Attachments
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Teken
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Re: System design

Post by Teken » Thu Mar 05, 2015 5:48 pm

This really comes down to preference and your over all budget. For the little added cost I would move from 40 to 50's. I would leave the micro 80's where you intended to use them anyways. Keep in mind the main feeds will be monitored by either a 100/200 CT which is based on 1% tolerances.

Your grouping plan of everyday circuits vs less used one is sound. For the stove you would be using two CT's one for the main and the other for the convenience outlet. Again I would upgrade from the 40 to 50 just for better accuracy and peace of mind.

Your biggest issue is breaking up drywall and running conduit for the install. At the end of the day you're only going to spend your money once so consider this an investment.

The $15-25.XX you spent for the micro 50 CT's will long be forgotten in a year!
Teken . . .

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ben
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Re: System design

Post by ben » Fri Mar 06, 2015 12:23 pm

Teken basically covered most of it.

One consideration is if the 240V loads have a neutral, if there's no neutral you can monitor it with 1 CT then double the value via firmware (as it's a balanced load).

Not sure of any electricians, but the CTs are fairly easy to install so any qualified electrician should be able to do it. Make sure there's good documentation on what is connected to what channel or you're going to have a heck of a time figuring it out later due to the space in your panel. Might want to put a label at each end of the CTs.

I've attached a fillable channel PDF one of our customers made. It may be handy.
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Ben
Brultech Research Inc.
E: ben(at)brultech.com
agr077
Posts: 37
Joined: Tue Jan 14, 2014 3:31 pm

Re: System design

Post by agr077 » Fri Mar 06, 2015 12:54 pm

I'd imagine that all the single breakers are 120v and the double ones are 240v. Is that correct?

How would I know if there is a neutral?

I realize that my electrician will know, I just don't want to overbuy CTs that I don't need.
Teken
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Re: System design

Post by Teken » Fri Mar 06, 2015 1:06 pm

agr077 wrote:I'd imagine that all the single breakers are 120v and the double ones are 240v. Is that correct?

How would I know if there is a neutral?

I realize that my electrician will know, I just don't want to overbuy CTs that I don't need.
Typically if there is a white wire connected to the breaker that is a neutral. This will be tied to the neutral bus bar in the service panel at the top / bottom. I would suggest however you order one or two extra's for the future should there be any changes required etc.

Buying now will save you future shipping costs etc for such a small item. I have never had a CT fail in all the years or read of anyone having a CT failure. But, having a few extra's is good practice for that what if.
Teken . . .

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sub3marathonman
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Re: System design

Post by sub3marathonman » Sat Mar 07, 2015 10:03 am

One thing that I found is that even though the Split-60 CTs are so expensive, I still wish I would have ordered a few more. I am finding that on stranded wire circuits they are great, since it is my opinion that the torque values for the breaker with stranded wire are much more critical. And if it is aluminum wire where the torque is critical, I would never loosen and retighten it myself, I'd either use a Split CT or else hire an electrician. Even if I was hiring an electrician, I'd still rather not have stranded wire loosened and retightened, but maybe that is being overly concerned.
agr077
Posts: 37
Joined: Tue Jan 14, 2014 3:31 pm

Re: System design

Post by agr077 » Tue Aug 30, 2016 10:12 am

Hi,

I am re-reviewing my plan design and I have a very specific set of questions about the CTs needed for a few of the breakers.

I've attached a picture with 4 sections highlighted.

Section #1: This is the breaker for the steam shower. There are 2 40s tied together. One has a red wire coming out and the other has a black wire. In my design, what kind of CT and on which of the wires? Do I need a micro 50CT on one or both of the wires or a micro 80CT on one or both of the wires because the total between the two is 80?

Section #2: This is the breaker that feeds a secondary panel in my backyard for my pool. There are 2 60s tied together. They both have black wires coming out. In my design, what kind of CT and on which of the wires? Do I need micro 80CT on one or both of the wires? or do I need the split 60CTs on one or both because the total between the two is 120?

Section #3: This is a breaker that feeds some plugs in some bedrooms. It has a 15 breaker but there is a black and a white wire coming out of it. Does this only need a 50CT on the black? Is the white a neutral?

Section #4: This is a 15 breaker with what looks to be just the one black wire coming out of it. I assume a 50CT goes on here. What is the difference between this and #3 from an electrical perspective. Why the two different looking setups for what looks to be individual 15 breakers?
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Teken
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Re: System design

Post by Teken » Tue Aug 30, 2016 10:31 am

1. A Micro 50 is perfectly fine for this circuit which you can use one or two CT's. I prefer to use two for accuracy even though its a balanced load.

3. Based on the image you have an illegal connection because you have two white neutral under one set screw. The only time this is permitted is if the breaker has been designed to do so. Confirm the two white wires enter a separate terminal and not simply under one another.

2. You will need Micro 80's because its a balanced 240 load with out a neutral you can use 1 or 2 CT's. I prefer to use two because depending upon the load there can be a variance and I like to see that difference which is really preference of accuracy.

4. I need a better picture but there appears to be a white sticker on the single wire. But directly below it is another 15 amp breaker with another white sticker. Are you sure someone didn't cheat and use two different breakers instead? What does the two breakers feed 120 VAC lights, 240 VAC load?
Teken . . .

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ben
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Re: System design

Post by ben » Tue Aug 30, 2016 11:08 am

agr077 wrote: Section #4: This is a 15 breaker with what looks to be just the one black wire coming out of it. I assume a 50CT goes on here. What is the difference between this and #3 from an electrical perspective. Why the two different looking setups for what looks to be individual 15 breakers?
#4 is a space saving quadplex breakers. It allows you to add 2 single-pole breakers along with a double-pole breaker in a smaller profile.

A 50A CT will work fine there on each of the 15A sides. You may be able to monitor the 40A middle with 1 CT (I'm unsure if it's balanced).
Ben
Brultech Research Inc.
E: ben(at)brultech.com
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