The Mandaluyong solar project came with one hard condition from the utility connection: the arrays must not push power into the grid. That turns the design question from "how much do we generate" into "how fast can we see export appearing, and what stops it".
Five AMC96L panel meters of the E4/HKC variant were installed for the job, one per monitored incomer, each watching the interconnection point of its own sub-array.
How the export limit is enforced
The meter reads forward and reverse power and energy at the interconnection point. As soon as the reverse (export) power passes the agreed threshold it signals the inverter over RS485, and the inverter stops delivering power to the grid. Threshold and response delay are set per project, so the same wiring covers a strict zero-export rule and a capped export of a few kilowatts.
The meter is the measuring element only. The throttling command reaches the inverter through a control input on the inverter itself, which is why the inverter brand and its Modbus register map have to be fixed before the order is placed.
Series data, from the published specification
| Item | AMC96L series |
|---|---|
| Wiring | Three-phase four-wire |
| Reference frequency | 45-65 Hz |
| Rated voltage | 3×57.7/100 V, 3×220/380 V, 3×380/660 V |
| Rated current | AC 1 A or AC 5 A secondary |
| Overload | Voltage 1.2× continuous, 2× for 1 s; current 1.2× continuous, 10× for 1 s |
| Input burden | Less than 0.5 VA per circuit |
| Auxiliary supply | AC/DC 85-265 V, less than 5 VA |
| Accuracy | Voltage and current class 0.2; active power and active energy class 0.5; reactive power and reactive energy class 1.0 |
| Communication | RS485, Modbus-RTU, 1200-38400 bps |
| Switching | Relay output 3 A / 30 VDC or 3 A / 250 VAC; 2 or 4 dry-contact inputs |
| Operating temperature | −10 to +55 °C, indoor installation |
Figures above are the series values published on the AMC96L product page. The exact order code is set by the wiring, the options and the supply chosen for the site.
Send us the inverter make and model with the one-line diagram: the export-control loop is finished at the inverter side, not at the meter.
Topology
Post time: Jun-25-2023
