Sub metering is not all that it (EKM v3) is good for.

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Nevland
Posts: 65
Joined: Tue Jul 31, 2012 2:56 pm
Location: Nevada City CA

Sub metering is not all that it (EKM v3) is good for.

Post by Nevland » Fri Aug 10, 2012 7:02 pm

I feel that there are other uses for the EKM v3 besides just sub metering. Here is mine.

I have an expensive stand by generator that lives in the barn, which is about 150' from the house.
OK Power from utility is out. 18" on snow on the ground between me and it.
It is reassuring to know that the generator is running within it's limits and it is feeling good.

Larger generators are expensive and are very expensive to repair, if you injure them. Well built units if treated kindly will last for generations.

When I found out about the EKM with remote read out I thought it would good to be able to read the meters on my laptop in the house. The generator and the transfer switch are well metered but those meters are out in the barn with the genni.

I got the split type current transformers because it didn't know exactly where I (in the circuit) wanted to install it.
Turns out that the output (Load side) of the transfer switch is best palace for me. So I didn't need the split type after all.

Mounted my Ekm meter on the door of the transfer switch. Fed the RS485 output to the house via an unused telephone line.
Lots of problems here re: fussy USB/485 converters, driver software, line polarity, line terminations etc. This is not a The EKM is not a Plug and Play devise.

The free software was ok but paid version allowed "logging" which when set as fast as possible, provided an almost real time monitor it also allowed resetting of "Max Demand". The down side is it had a lot more info in it that I needed or wanted.

Could I write my own small program, hard code my meter # and password in it. Why not try it. So I started to write my own using VB98. Why VB 98, cause I had it. Turns out VB98 would not work in Windows 7. OK, blew the dust off my 15 years old XP laptop. Got the parsings and protocol info from EKM and got to work. It turns out microsoft did not address serial communications very well in VB98. I guess they thought everybody would use USB's Tracked down updates etc. Dealt with Hex code issues etc. Note: Microsoft no longer supports VB98

Semi Bottom Line
I now have a small fast program with alarm limits that seems to work well. It comes on the screen having already read the meter parameters.
I will post Screen shot and source code if requested.

Whats Next
Look and see what else the might be useful that is hiding inside the EKM.
See post on End of month KWH reading.

I only use 4 of the 6 meter inputs as my system is single phase.
What can I use the other 2 unused inputs for?

How about a little black box that takes temperature in and outputs AC volts that is proportional to temperature. ?
How about a little black box that takes pressure in and outputs proportional current.

More later

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