JLD404 sub panel monitoring

bpescaaz
Posts: 1
Joined: Mon Jun 13, 2011 8:39 am

JLD404 sub panel monitoring

Postby bpescaaz » Tue Jun 14, 2011 9:04 pm

Is your jld404 meter capable of measuring single phase 230 3wire sub panel. L1-L2-N. if so can you send me a diagram using two cts.

Tech_Marco
Posts: 4311
Joined: Mon Jun 15, 2009 3:00 pm

Re: JLD404 sub panel monitoring

Postby Tech_Marco » Wed Jun 15, 2011 11:47 pm

You can do L1-N, or L2-N, or L1-L2 but not all in one as the meter is a single phase.

etrmedia
Posts: 15
Joined: Mon Jan 23, 2012 5:36 pm

Re: JLD404 sub panel monitoring

Postby etrmedia » Sun May 06, 2012 6:32 pm

Hypothetically, wouldn't measuring L1-L2 also include draw on L1-N?

bob21635
Posts: 12
Joined: Mon Mar 25, 2013 5:54 pm

Re: JLD404 sub panel monitoring

Postby bob21635 » Tue Apr 02, 2013 4:52 pm

Example pictures would be very helpful. I am monitoring a 30A, 240V, 3 wire load. The JLD404 did not come with any instructions, and the download doesn't explain the CT connection.

Tech_Marco
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Joined: Mon Jun 15, 2009 3:00 pm

Re: JLD404 sub panel monitoring

Postby Tech_Marco » Tue Apr 02, 2013 5:45 pm

bob21635 wrote:Example pictures would be very helpful. I am monitoring a 30A, 240V, 3 wire load. The JLD404 did not come with any instructions, and the download doesn't explain the CT connection.


Fig 6. did show the connection of the C.T. Simply connect the two terminals of the C.T. to the I1, I2 of the meter. To measure the current flow, you need to pass the load line through the hole of the C.T. That's all you need to do

Marco

bob21635
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Joined: Mon Mar 25, 2013 5:54 pm

Re: JLD404 AC Wiring

Postby bob21635 » Wed Apr 03, 2013 7:00 am

Hi Marco

I understand all of that in fig 6 for 120V, but for 240V single phase you only sample one power leg?
Does that indicate only half the wattage?

If you put both power legs L1 + L2 through will it read total wattage? Another CT guide I read says the direction of the CT must be oriented the right direction with the power wires, is that true?
Is there a manual for the CT to download?

Which direction does it go and are the terminals the same on both sides of the CT? Also the CT guide showed the L1 and L2 crossing like an X inside the CT from the opposite sides of the CT, is that required? I will send you a copy of the guide, you might want to post it.

The JLD404 AC looks to be a very well built device, I just wish there were better instructions included.
There is no information online for it either except here.

BTW- The JLD404 DC has lots of information online and videos for use in electric cars!

Sincerely
Bob
Last edited by bob21635 on Fri Apr 05, 2013 3:14 am, edited 1 time in total.

bob21635
Posts: 12
Joined: Mon Mar 25, 2013 5:54 pm

Re: JLD404 sub panel monitoring

Postby bob21635 » Wed Apr 03, 2013 4:23 pm

Installing a CT

The primary winding of the CT is a wire that carries the current you want to measure. If you clip your CT around a two- or three-core cable that has wires carrying the same current but in opposite directions, then the magnetic fields created by the two wires are equal and opposite and will cancel. Your CT will have no output.

http://openenergymonitor.org/emon/buildingblocks/ct-sensors-introduction

Current Sensing Transformer Wire Diagram.gif
Crossed wires inside CT on 240V circuit.
Current Sensing Transformer Wire Diagram.gif (44.44 KiB) Viewed 4615 times


A picture is worth a thousand words!

Can we get a clear diagram like this for the JLD404 AC connections?

Tech_Marco
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Joined: Mon Jun 15, 2009 3:00 pm

Re: JLD404 sub panel monitoring

Postby Tech_Marco » Thu Apr 04, 2013 6:34 pm

Bob:

Thank you for the good picture. It helps to understand how to monitor the unit US 220V "Two phase" power. Usually, AC220V is single phase common in other country. But US AC220V is combined by two AC110V. So, it's not as common as other country like Hong Kong or China where the electricity is true "Single phase" AC220V. "Two phase" is a strange terms to be used but it is the case here in US. Some argued that it is still a single phase while the other called it "Two phase". Which terms you preferred, though?


Marco

bob21635
Posts: 12
Joined: Mon Mar 25, 2013 5:54 pm

Re: JLD404 sub panel monitoring

Postby bob21635 » Thu Apr 04, 2013 7:02 pm

I studied the drawings and came up with my own design for 220/240V single phase applications.
This is what I came up with, I hope it helps others with the same situation.
I'm have been unable to find small isolation transformers nearby, anyone have any ideas?
Would small inline fuses be acceptable?
http://baida-china.cn
Marco - Please make these 120/120V, 220/220V, and 240/240V isolation transformers available for sale?


Isolation Transformer.JPG
Isolation Transformer.JPG (22.65 KiB) Viewed 4602 times


Basic 120V system

JLD404 AC Fig 4.JPG
JLD404 AC Fig 4.JPG (30.1 KiB) Viewed 4604 times


Expanded 120V system with Current Transformer and Isolation Transformer

JLD404 AC Fig 6.JPG
JLD404 AC Fig 6.JPG (34.53 KiB) Viewed 4604 times


120V connections (My basic JLD404 does not have the optional 2 relays or analog output)

JLD404 AC Fig 5.JPG
JLD404 AC Fig 5.JPG (58.63 KiB) Viewed 4604 times


220/240V connections (3 or 4 wire systems)

JLD404 AC Fig 7.JPG
JLD404 AC Fig 7.JPG (51.65 KiB) Viewed 4598 times


220/240V wiring 3 wire (220/240V only) Notice crossed wires in CT

JLD404 AC Fig 8.jpg
JLD404 AC Fig 8.jpg (44.35 KiB) Viewed 4604 times


240V wiring 4 wire (120/240V) USA only

JLD404 AC Fig 9.jpg
JLD404 AC Fig 9.jpg (46.5 KiB) Viewed 4604 times
Last edited by bob21635 on Fri Apr 05, 2013 7:44 am, edited 10 times in total.

Tech_Marco
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Re: JLD404 sub panel monitoring

Postby Tech_Marco » Thu Apr 04, 2013 7:20 pm

Why do you need the transformer? The meter by default can handle up to 500v without the transformer

Marco

bob21635
Posts: 12
Joined: Mon Mar 25, 2013 5:54 pm

Re: JLD404 sub panel monitoring

Postby bob21635 » Thu Apr 04, 2013 7:36 pm

Tech_Marco wrote:Why do you need the transformer? The meter by default can handle up to 500v without the transformer

Marco


Fig 6 in the JLD404 AC manual recommends the use of an isolation transformer. They are installed mainly for safety to isolate the high current from shorting out through the unit. Might not be legal to install without them? Anyone know for sure? What does the JLD404 manufacturer say?
http://en.wikipedia.org/wiki/Isolation_transformer

Bob

bob21635
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Joined: Mon Mar 25, 2013 5:54 pm

Re: JLD404 sub panel monitoring

Postby bob21635 » Fri Apr 05, 2013 3:30 am

deleted
Last edited by bob21635 on Fri Apr 05, 2013 4:13 am, edited 3 times in total.

bob21635
Posts: 12
Joined: Mon Mar 25, 2013 5:54 pm

Re: JLD404 sub panel monitoring

Postby bob21635 » Fri Apr 05, 2013 3:44 am

Marco

After an extensive search for small isolation transformers, this is the only source I found.
http://baida-china.cn/
They only cost $2 a piece, but have a minimum order of 200 pieces, since they are each custom made.
You could resell them on eBay for at least $10 and get more traffic flow to your website.
They can also be used with any other AC equipment on your website or elseware.
The power equipment I'm designing to sell would require them also.

Bob
Last edited by bob21635 on Sun Apr 07, 2013 11:59 am, edited 1 time in total.

bob21635
Posts: 12
Joined: Mon Mar 25, 2013 5:54 pm

Re: JLD404 sub panel monitoring

Postby bob21635 » Fri Apr 05, 2013 4:11 am

Tech_Marco wrote:Bob:

Thank you for the good pictures. It helps to understand how to monitor the unit US 220V "Two phase" power. Usually, AC220V is single phase common in other country. But US AC220V is combined by two AC110V. So, it's not as common as other country like Hong Kong or China where the electricity is true "Single phase" AC220V. "Two phase" is a strange terms to be used but it is the case here in US. Some argued that it is still a single phase while the others call it "Two phase". Which terms do you prefer, though?

Marco


Marco

240V 4 wire "2 phase" is really quite simple. We still call it single phase though.

L1 + L2 = 240V (Just like the 3 wire 220/240V systems)

L1 + N = 120V

L2 + N = 120V

In the case above the Neutral wire is not used at all and can be compleately ignored!

Bob
Last edited by bob21635 on Fri Apr 05, 2013 8:48 am, edited 1 time in total.

bob21635
Posts: 12
Joined: Mon Mar 25, 2013 5:54 pm

Re: JLD404 sub panel monitoring

Postby bob21635 » Fri Apr 05, 2013 4:28 am

bpescaaz wrote:Is your jld404 meter capable of measuring single phase 230 3wire sub panel. L1-L2-N. if so can you send me a diagram using two cts.


You can measure the total wattage from both L1 and L2 through one CT if the wires cross inside.
To measure each leg seperately would require 2 JLD404 systems or one JLD404 with 2 CT's and a switch to select each leg.
Fig 7 + 8 diagram above.

Bob
Last edited by bob21635 on Fri Apr 05, 2013 8:42 am, edited 2 times in total.


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