Current Clamp not Working

Hi All,
I have setup Flukso but, cannot get any power reading from clamp. I have plugged clamp into screw terminal one with positive and negative wires connect as per polarity described to clamp and fluskso screw terminal.

I am using flukso-read-mqtt.py to read the values being read by clamp. Unfortunately it is always 0 however if I unscrew the clamp end of the cables and hold one cable in each hand I get small readings of 2 or 3 watts.

The clamp itself however seems to be dead.

Clamp is 100amp and Fluskso is FLM02A.

Clamp is clamped to power board my pc runs off for testing. Voltage is 240 (Australian) and heartbeat is occurring to Flukso.net.

Anyone had similar problem? Should I purchase another current clamp?

Cheers
Chris

gebhardm's picture

Be aware that a current clamp works on a live wire only, so never assume it is working around a "normal" power cable that has live and neutral in it (here the magnetic field is annihilated)... - see http://en.wikipedia.org/wiki/Current_transformer and how it fetches the magnetic field...

Ricstar's picture

I also have Issues with clamps, but with accuracy.

Flukso reporting over by 6% for Hot water and 20% for main Power consumption.

Flukso – latest Firmware 232, two clamps (50A), One on Hotwater only and a 2nd on Main, which is before solar ( So no solar going through this clamp) and has only 2 x GPO circuits, Lights, Oven and hotplates.

Hi .
I got my Flukso setup around the 28th March

I use a Laptop (Serial RS232 to Xantrex to upload Solar PV Generation data to PVOutput and the Flukso to upload Consumption data off the Main – House circuits only. To Flukso, then onto PV Output. Data at PV Output is same as what is in Flukso portal.

Readings after 1 day showed my Flukso reporting Tar11 – 20% more consumption than what my meter says – Hot Water T33 can't tell with my old dial meter, so did readings at beginning and end of 9 days.

So Meter says over the 9 days:
Consumed 46Kw from the Grid
Generated to grid 100Kw

PV Output over 9 days says:
I generated 122.6Kw
Flukso says I consumed 85.41Kw

So my Flukso Consumption is 85.41Kw whereby (122.6Kw Gen – 100Kw into Grid via Meter =22.6Kw came from my solar and 46 from grid = 68.6KW. Which shows Flukso is 16.81Kw over what I really must have used. Which is approx 20%

My Off Peak Hot water, also only on from midnight to 8am (Hot water system actually on heating for just under an hour) is approx shows I used 33.5Kw and Flukso says I used 38.77Kw which is 5.2 more than what my meter says which is 6% over. Also sometimes, even if hot water elment is not heating, Flukso says I am drawing 3A or say 7 A, but no amps are bing drawn. This is intermittent. Some days I get this phantom usage, other days, I don't.

Any idea's?

Is there any way i can adjust the Flukso down by 20 % on my Tar11 and 6% on my Off Peak T33 Hot water?
Why would it be out buy so much?

Both my Flukso Consumption and Hot Water Consumption feed via Flukso into PV Output, Same account in Flukso, but I have the Hot Water on a separate accounts, so the two are completely separated in PV Output. (So not combining the sum of the two
Only my Tar 11 Via Flukso and and Solar PV from my Xantrex / Laptop are on one PV Output account.

Appreciate assistance.

Is this usual to be 20% out or a clamp on hoursehold consumption and 6% on a hot water element?
Can this be adjusted on the Flukso Meter or at the web site?

Thanks in advance

vk2him's picture

I'm using a 50A clamp and my system is very accurate, do you have any large inductive or capacitive loads as they will not show correctly?

A quick way to check accuracy is to turn off power to all circuits except one power circuit. Then ensure all power points are off so no load is being drawn - the minute tab on should show near zero. Now connect a kettle that you know exactly how many watts/amps it draws and turn it on - the minute tab should reflect that usage pretty close.

Ricstar's picture

Hot water element - Only load on T33 Clamp draws between 3912w and 4032w instant - Total of say 3670wh when on for about 50 minutes in a day. Usually from midnight to 1am.
So Flukso shows approx 6% more that what my meter says after 9 days.

Main household consumption. on Main Clamp shows from an average low of 200 watts, eg during the evening to say 700 watts average during the day. Will peak to 2kw when kettle is turned on for say 2 minutes. We dont use a lot of power.

Most standby loads are transformers for say PVR, Laptop Power supply, Cordless phone power packs, Movement sensors for outside lights, and Fridge with airflow fan running.

Additional loads are Kettle, Microwave for short periods, Fridge Compressor motor turning on cycling say every 20 minutes for say 20 minutes and once a day Fridge Defrost element coming on for say 30 minutes.
Lighting is mixture of Compact Flouro and LED. Mostly LED for main lights and table lamps.

So this is what is out by 20% a day.

My first day with Flukso setup, it was out by 25% with the Flukso set at 240v, however my Solar PV Monitoring shows voltages during the day vary from 231 to 251v.

Maybe my average is not 240V so need to increase Flukso voltage to be say 250v, but 10v on 240v is less than 5%, not 20%.

Luc Wuyts's picture

I had a clamp with wrong polarity indication on it.
I switched the red and black wires, and it worked.