24.02.2018, 00:29
I am not able of getting consistent current readings.
I am using 4 different split core current transformers and attached them to the same cable that is powering up my pc so that ideally I have the same readings across all the SmartPi inputs. I am not measuring voltage and my RaspberryPi is powered up by a usb cable attached to the wall socket . Also the pins on my smartpi that are directly above my sensor inputs do not have any jumper installed except for I4 (not sure whether this is the correct installation - i removed the jumper for the picture)
I have also made sure that the contents of the file in /etc/smartpi have the following keys:
ct_type_1 = YHDC_SCT013
ct_type_2 = YHDC_SCT013
ct_type_3 = YHDC_SCT013
ct_type_4 = YHDC_SCT013
ct_type_1_primary_current = 100
ct_type_2_primary_current = 100
ct_type_3_primary_current = 100
ct_type_4_primary_current = 100
The two tests that I carried out were the following:
1. Make a full rotation of the connected current sensors connected to the smartpi i.e. I1 -> I2, I2 -> I3, I3 -> I4, I4-> I1 and so on. With this test I wanted to check if the result for each current sensor was consistent across inputs.
2. Make a full rotation of the clamps on the target measurement without changing the sensors connection (should not affect measurement)
However once I start the smartpireadout program I am not able to get the same value for all four current transformers.
Amongst the issues I have seen the following:
1. Measured current has differen values on every phase.
2. I4 input is the only one with the jumper installed on its jumper pins. This causes the reading to allways be a negative negligible value
3. The change_current_direction_X flag doesnt change the current sign, doesnt matter if set to 0 or 1
4. Rotating the clamp position along the same conductor renders different current measurements (no idea why this is happening)
These are the results for my tests
========= CONNECTION ROTATION 1 =========
I1: 1.6912797688692927 I2: 0.514815652681119 I3: 2.2674108816131033 I4: -0.05206709488183494
========= CONNECTION ROTATION 2 =========
I1: 0.06681043028378475 I2: 1.6093356501077427 I3: 0.5131641588988232 I4: -0.0834154495857771
========= CONNECTION ROTATION 3 =========
I1: 2.111149542648242 I2: 0.07515798067429807 I3: 1.6693899694639536 I4: -0.0578022823803531
========= CONNECTION ROTATION 4 =========
I1: 0.4911242236950937 I2: 2.190541352837153 I3: 0.08903052844558285 I4: -0.05125636157052611
========= CONNECTION ROTATION 5 (MATCHES CONNECTION ROTATION 1)/ CLAMP ROTATION 1 =========
I1: 1.3731720392394429 I2: 0.3151350408217172 I3: 2.119587174517789 I4: -0.06693053892249717
========= CLAMP ROTATION 2 =========
I1: 2.0377931915546306 I2: 0.9799964104143295 I3: 2.0613945390616215 I4: -0.07572849670818207
========= CLAMP ROTATION 3 =========
I1: 1.1113652340060411 I2: 0.7465652710767372 I3: 2.000499459234423 I4: -0.07077401536129468
========= CLAMP ROTATION 4 =========
I1: 1.0695674277341183 I2: 0.013782466292250427 I3: -0.004444019632359615 I4: -0.0753081164726886
========= CLAMP ROTATION 5 =========
I1: 3.326889183695378 I2: 0.20892897704025812 I3: 0.46749284902842464 I4: -0.07894140279373937
Do you have any idea why this is happening?
Greetings
Luis.
I am using 4 different split core current transformers and attached them to the same cable that is powering up my pc so that ideally I have the same readings across all the SmartPi inputs. I am not measuring voltage and my RaspberryPi is powered up by a usb cable attached to the wall socket . Also the pins on my smartpi that are directly above my sensor inputs do not have any jumper installed except for I4 (not sure whether this is the correct installation - i removed the jumper for the picture)
I have also made sure that the contents of the file in /etc/smartpi have the following keys:
ct_type_1 = YHDC_SCT013
ct_type_2 = YHDC_SCT013
ct_type_3 = YHDC_SCT013
ct_type_4 = YHDC_SCT013
ct_type_1_primary_current = 100
ct_type_2_primary_current = 100
ct_type_3_primary_current = 100
ct_type_4_primary_current = 100
The two tests that I carried out were the following:
1. Make a full rotation of the connected current sensors connected to the smartpi i.e. I1 -> I2, I2 -> I3, I3 -> I4, I4-> I1 and so on. With this test I wanted to check if the result for each current sensor was consistent across inputs.
2. Make a full rotation of the clamps on the target measurement without changing the sensors connection (should not affect measurement)
However once I start the smartpireadout program I am not able to get the same value for all four current transformers.
Amongst the issues I have seen the following:
1. Measured current has differen values on every phase.
2. I4 input is the only one with the jumper installed on its jumper pins. This causes the reading to allways be a negative negligible value
3. The change_current_direction_X flag doesnt change the current sign, doesnt matter if set to 0 or 1
4. Rotating the clamp position along the same conductor renders different current measurements (no idea why this is happening)
These are the results for my tests
========= CONNECTION ROTATION 1 =========
I1: 1.6912797688692927 I2: 0.514815652681119 I3: 2.2674108816131033 I4: -0.05206709488183494
========= CONNECTION ROTATION 2 =========
I1: 0.06681043028378475 I2: 1.6093356501077427 I3: 0.5131641588988232 I4: -0.0834154495857771
========= CONNECTION ROTATION 3 =========
I1: 2.111149542648242 I2: 0.07515798067429807 I3: 1.6693899694639536 I4: -0.0578022823803531
========= CONNECTION ROTATION 4 =========
I1: 0.4911242236950937 I2: 2.190541352837153 I3: 0.08903052844558285 I4: -0.05125636157052611
========= CONNECTION ROTATION 5 (MATCHES CONNECTION ROTATION 1)/ CLAMP ROTATION 1 =========
I1: 1.3731720392394429 I2: 0.3151350408217172 I3: 2.119587174517789 I4: -0.06693053892249717
========= CLAMP ROTATION 2 =========
I1: 2.0377931915546306 I2: 0.9799964104143295 I3: 2.0613945390616215 I4: -0.07572849670818207
========= CLAMP ROTATION 3 =========
I1: 1.1113652340060411 I2: 0.7465652710767372 I3: 2.000499459234423 I4: -0.07077401536129468
========= CLAMP ROTATION 4 =========
I1: 1.0695674277341183 I2: 0.013782466292250427 I3: -0.004444019632359615 I4: -0.0753081164726886
========= CLAMP ROTATION 5 =========
I1: 3.326889183695378 I2: 0.20892897704025812 I3: 0.46749284902842464 I4: -0.07894140279373937
Do you have any idea why this is happening?
Greetings
Luis.