Resized - might have been the problem
Resized - might have been the problem
How is it possible that the load power can be higher than the grid power ? I would have expected the grid to be slightly higher than the load on all 3 phases..
The grid power consumption is slightly higher than the load power consumption.Originally Posted by Derlyn
One curiosity is the power draw is similar on both inverters, but the current on one is nearly double the current reported on the other.
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Slightly ? - grid shows 25Amp on one inverter which should be around 5Kw and yet it show +/-1 and the 2nd inverter 14 Amps which should show +/-3Kw yet both show 1 Kw
I thought CT's were in wrong position but when we ran off grid it started the confusion
Resized - might have been the problem
I was looking at the on-grid-supply power numbers. Looks like there's a 100w overhead on each inverter according to the power report.
I agree the current reports raises red flags - properly.
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Yip and that is where I come back to the KW readings on inverter not matching actual draw
The inverter picks up the current, total , at +/-38 amps which is what I get on the combined load
The total grid power( 3 pases added together) is higher than the load, but there are individual phases where the load power exceeds the grid power. That's what I was referring to.
Another question. You said there are 4 escalators if I'm not mistaken. Does each inverter feed 2 escalators or do both inverters , in parrallel, feed all 4 escalators ?
Inverters are in Parallel and supply all 4
Discrepancy on phases can be motor loads and power sharing between phases - You often find 1 phase on a motor drawing less and that is generally due to incoming powerfactor - Can be as much as 10% in extreme cases
How about the phases on the one inverter (the one with the high current readings) are wired incorrectly?
My read is the evidence suggests the power draw readings are the most likely to be reasonably accurate. (DC draws off the battery - both in current and SOC after a couple of hours, one inverter fairly close to 3kW across all measures).
So what could cause a massive current discrepancy in a star supply to delta load situation?
In a rig installed by an IT guy.
On a supply with a phase rotation that runs the wrong way (compared to the rest of the country).
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The mains supply is a star config and transformer is 20m away so I don't see any reason that there should be a change
The phase rotation - don't see that making any difference
Can only think that it is PF of the motors and incoming PF
On the incoming there is a power factor correction panel that is working and keeping PF at 0.98
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