Looking for a 600 amp 3 phase TOU / net meter

potter · April 2014

I have a 600 amp 3 phase (4 wire) 120/208 service that is billed under a 3 tier time of use billing with net metering. I need something that is easy to under stand so I'm able to track and use my power more efficiently the way I'm billed.

I have been talking to my electrician and he is unable to recommend anything, but tells me he will be able to install anything that uses CT's for the metering.

My RE equipment.
6 – 6048 SMA island inverters
3 – Sunny Boy 3800 (3900 watts of solar each)
2 – 8,000 watt screw hydro plants
2 – 24-125-13 battery packs. 48V 1182 @ 20 hours

SkiDoo55 · April 2014

Re: Looking for a 600 amp 3 phase TOU / net meter

http://www.ekmmetering.com

They have some digital meters that use CT's price is reasonable also.

solar_dave · April 2014

Re: Looking for a 600 amp 3 phase TOU / net meter

TED has 3 phase now as well
http://www.theenergydetective.com/pro800

BB. · April 2014

Re: Looking for a 600 amp 3 phase TOU / net meter

You might need a power engineer/consultant... This is not "trivial" 120/240 VAC mains (and the consultant may not be cheap--Perhaps talk with your solar installer for some references).

In California, the tariffs for commercial can be quite complex (including power factor/peak power--both consumed and output to grid, as well as TOU, etc.). In some cases, solar can actually increase the power bills for commercial customers (i.e., summer weekend peak 15 minute output exceeds week day power usage--Sets the "demand/reservation charges" for the next 1-12 months (in California, very roughly 50% of the bill is reservation charges and the other 50% is actually kWH billing).

-Bill

potter · April 2014

Re: Looking for a 600 amp 3 phase TOU / net meter

Thank you SkiDoo55, solar_dave, and BB.

I did look at ekmmetring and did not see what I was looking for. I might of missed it.

From what I have read TED PRO 800 is about what I’m looking for. I might of missed it, but it dose not look like it logs PF. I'll keep searching there website and call them Monday to make sure I get what I need. Thanks solar_dave.

BB
There was a lot of planning when it came to peak power. With out setup we are not penalized for our PF and dose not show up on our bill at all. I do wounder about if some PF correction would help us with our electric kilns or when we are holding a class with 20 variable speed 1 HP motors running. I'm hoping to be able to log the PF so I can sit down with someone with a month or 2 of data and look at it.

potter · April 2014

Re: Looking for a 600 amp 3 phase TOU / net meter

Would I need to use shunts and not CT clamps because there is a possibility that power would flow both ways from the SMA Island inverters?

BB. · April 2014

Re: Looking for a 600 amp 3 phase TOU / net meter

CT's should work fine for AC (shunts can be used with DC or AC).

In either case, with AC you will need voltage tap(s) too... It is the Vector Math of both Voltage and Current that allows you to calculate all of the numbers (power, VA, PF, direction of power flow, etc.).

With a CT (or shunt) only connection, you do not know the Voltage phase and amplitude--So none of the other data can be computed.

I am out of my comfort zone with large AC power systems--I don't know what is common and customary. You might find a knowledgeable licensed electrician--But for your installation--You may be forced (by code/Utility) or safety to use a licensed Power Engineer (PE--Professional Engineer).

Many times, the first effort is confusing and you need to hire people with the knowledge. After you have seen it once--You will see how things work and you can make more informed decisions down the road.

-Bill

solar_dave · April 2014

Re: Looking for a 600 amp 3 phase TOU / net meter

potter wrote: »

Thank you SkiDoo55, solar_dave, and BB.

I did look at ekmmetring and did not see what I was looking for. I might of missed it.

From what I have read TED PRO 800 is about what I’m looking for. I might of missed it, but it dose not look like it logs PF. I'll keep searching there website and call them Monday to make sure I get what I need. Thanks solar_dave.

BB
There was a lot of planning when it came to peak power. With out setup we are not penalized for our PF and dose not show up on our bill at all. I do wounder about if some PF correction would help us with our electric kilns or when we are holding a class with 20 variable speed 1 HP motors running. I'm hoping to be able to log the PF so I can sit down with someone with a month or 2 of data and look at it.

My TED 5000 does collect PF but not sure about the historic recording of it, I would have to look a bit to find out. You probably want 2 sets of CTs one for the solar output and one to calculate the net from the main line.

potter · April 2014

Re: Looking for a 600 amp 3 phase TOU / net meter

I forget that some CT meters can log bidirectional power flow and is something that I would need.

I need to go back to playing in clay. Electricity is to complicated.

SkiDoo55 · April 2014

Re: Looking for a 600 amp 3 phase TOU / net meter

The EKM meters use CT's and tape each leg for voltage reference, as does TED. EKM can handle up to 5000 amps with there CT's and setting the meter. They will record flow both directions for NET and with optional interface can push data for remote access. Meter for 3 phase is about $190 plus the CT's.
i have been wanting to get one just haven'T pulled the trigger to monitor my solar along with the TED system.

EKM meter, 600 amp CT's, comm device, USB interface, inline fuse for voltage sense @ $430. For 3 phase 4 wire system. Certified for utility grade accuracy.

David and Laura · April 2014

Re: Looking for a 600 amp 3 phase TOU / net meter

We'd recommend taking a look at the pQube from Power Standards Lab:

http://www.powerstandards.com/PQube.php

We have two pQubes installed in our solar system, and we're very happy with the information that they collect, which includes true power factor, VARs, with support for bidirectional power transfer. You'd need to extract the information via ModBus or Ethernet and calculate the TOU billing based on how you are billed.

Alternatively, you may want to consider a Nexus 1500, which can be picked up quite inexpensively here:

http://www.ebay.com/itm/Electro-Industries-GaugeTech-Nexus-1500-Advanced-Power-Quality-Monitor-Shark-/380876381609

(No relation with the seller)

potter · April 2014

Re: Looking for a 600 amp 3 phase TOU / net meter

I talked to TED company and they look like they are the way to go. I talked to my electrician and he told me he would look at it and get back to me Tuesday. He says he will dig into to it more.

solar_dave · April 2014

Re: Looking for a 600 amp 3 phase TOU / net meter

potter wrote: »

I talked to TED company and they look like they are the way to go. I talked to my electrician and he told me he would look at it and get back to me Tuesday. He says he will dig into to it more.

Just be aware the setup on a TED can be quite a challenge. Also the software has some TOU limitations. it really doesn't line up with my TOU plan very well.

potter · April 2014

Re: Looking for a 600 amp 3 phase TOU / net meter

My electrician did not like the TED system after talking to them.

He was talking to one of his colleagues and he suggested to get a sub meter that is approved in our state. There was 2 brands that were recommended and both log to a SD card, can see the current information live, and are some what easy to set up. He suggested getting one that was dual meter and using CT clamps on the second set so it could be moved to the different sub panel feeds as needed for trouble shooting down the road.

Looking for a 600 amp 3 phase TOU / net meter

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