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ACPower Instruction in CR6 doesnt measure current

XxVashxX Jan 12, 2021 02:23 PM

Hello, please can you help me with next question

I have a voltaje transformer and a current transmiter to measure power (With AC Power Instruction)

Voltaje transformer is magnelab 460 Vac In / 0.333 Vac Out (connected to U1 -U2 Diff Channel, U2 bridge to earth)

Current transmiter measurement range 50 Amp input, output 5 Vdc (Connected to U3 Single ended)

I made measurements in a CR1000X and everithing works great, use the next configuration:

ACPower (AC_PowerIn(),1,50,1,460/333,460,3,0.01,50,1)

Then i replicate the same program in a CR6 Datalogger (same sensors to do the same but for some reason the current measurement simply dont obtain reasonable measurements), i use next configuration in CR6:

ACPower (AC_PowerOut(),1,50,U1,1.38138138,460,U3,0.01,50,1)

But the current mesaurements dont made any sense, i compare mesaurements with a fluke meter and CR1000X are pretty much the same, in example Fluke and CR1000X mesaure around 6 Amp and CR6 mesaure around 0.17 Amp

CR1000X have OS 4.02

CR6 have OS 10.02

Could be something in the OS of CR6 or some different way to configure the multiplier in CR6???

Thank you for any help on this

L Jacobsen Apr 21, 2021 08:38 AM

Thanks for the question.

For the CR1000X and the CR6, the current input to the logger for the ACPower instruction must be supplied by a current transformer. The output from this transformer (and input to the logger) is AC rather than DC. It's not clear how a 5 VDC input appeared to work on the CR1000X. 

L Jacobsen Apr 21, 2021 08:51 AM

On a side note, the loggers' voltage measurements from the voltage transformer are single-ended. You may as well connect the wire from the voltage transformer secondary directly to ground rather than U2 and then bridging to ground. This  suggestion makes U2 available for some other single-ended measurement. This is true for either the CR6 (U2) or the CR1000X (Diff 1L - SE 2). 

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