Standar Operating Procedure - Hybrid Inverter
Standard Operating Procedure (SOP): Hybrid Inverter System
Document ID | Version | Effective Date | Prepared by | Approved by |
EVVO - SOP-HY-INV-01 | 1.0 | 19/09/2025 | Palani Murugan M | Gomes Christropher |
1.0 Purpose
To establish safe and standardized procedures for the operation, monitoring, and basic troubleshooting of the hybrid inverter system to ensure reliable power supply, maximize battery life, and ensure personnel safety.
2.0 Scope
This SOP applies to all authorized personnel responsible for the operation, daily checking, and basic maintenance of the hybrid inverter system at Site.
3.0 Definitions
- Hybrid Inverter: A device that can simultaneously manage power from solar panels, the utility grid, and a battery bank. It can invert DC to AC and rectify AC to DC for charging.
- PV (Photovoltaic): Solar panel array.
- SOC (State of Charge): The percentage of charge remaining in the battery bank.
- Utility Grid:** The main electrical power supply from the local electricity provider.
- BMS (Battery Management System): The system that protects the battery (e.g., Li-ion, Lead-Acid) by monitoring its state.
- EPS / Backup Power Outlet: Emergency Power Supply outlets that are active only during a grid outage.
4.0 Safety Precautions & Personal Protective Equipment (PPE)
**WARNING:** Failure to follow safety procedures can result in severe injury, electrocution, or equipment damage.
* PPE Required: Safety glasses, insulated gloves, and non-conductive footwear must be worn when performing any physical inspection or maintenance inside the inverter or battery compartments.
* De-energize: Before performing any maintenance (not daily operations), power down the entire system in the correct sequence (see Section 7.0).
* AC and DC Hazard: The system contains both high-voltage AC (from grid and inverter output) and high-voltage DC (from solar panels and batteries). Both are dangerous.
* Solar Panels: PV arrays produce voltage whenever there is sunlight, even if the inverter is off. Exercise caution around DC wiring.
* Batteries: Risk of electrical shock, short circuit, and thermal runaway. Do not expose batteries to open flames or sparks. Ensure the area is well-ventilated.
* Qualified Personnel:** Only personnel trained on this specific system should operate or maintain it.
5.0 Normal Daily Operation & Monitoring
The inverter is designed to operate automatically. Daily tasks involve visual inspection and data monitoring.
5.1 Daily Visual Check (Operator Round)
1. Walk by the inverter installation area.
2. Note any unusual noises (e.g., loud humming, buzzing, alarm beeps).
3. Inspect
* Check for any warning lights or error codes on the inverter display.
* Ensure all status LEDs are as expected (e.g., green for normal operation).
* Check for any signs of damage, discoloration, smoke, or burning smells.
* Ensure ventilation vents are not blocked.
4. Record: Log key parameters (see below) in the system logbook.
5.2 Monitoring via Display/App (Key Parameters to Check)
1. Mode of Operation: Confirm the inverter is in the desired mode (e.g., *Solar First*, *Grid-tied*, *Backup*).
2. Power Flow: View the screen to see:
- Solar Generation: in kW (e.g., 3.5 kW)
- Grid Import/Export: arrow toward Grid (export) / arrow inward from Grid (e.g., Importing 0.5 kW / Exporting 2.0 kW)
- Home Consumption: in kW (e.g., 4.0 kW)
- Battery SOC: (e.g., 85%) and charge/discharge power (e.g., Charging at 1.5 kW)
3. Energy Logs: Review daily solar production, home consumption, and grid interaction via the monitoring app (e.g., SolisCloud, SolarMan, SunSynk).
6.0 Standard Operating Modes & Configuration
Understand the primary modes set during installation. **Changing modes should typically only be done by trained personnel.**
* **Mode 1: Priority Solar (Self-Consumption)**
Operation: Solar power powers the home first. Excess solar charges the battery. Any further excess is exported to the grid. If solar is insufficient, power is drawn from the battery. If the battery is low, power is drawn from the grid.
User Case: Normal daily operation to maximize solar use and reduce electricity bills.
* **Mode 2: Backup Mode**
Operation: The inverter keeps the battery fully charged (or at a set SOC, e.g., 90-100%) using solar or grid power. The system will only use the battery to power designated backup circuits **when the grid fails**.
Use Case: Stormy weather or when expecting a grid outage. Ensures backup power is available.
* Mode 3: Time-of-Use (TOU) Management**
* Operation: The inverter is programmed to charge the battery with cheap off-peak grid electricity and/or solar energy, and then discharge it to power the home during expensive peak hours. Avoids grid import during peak rates.
* Use Case: Homes on a time-of-use electricity tariff.
* Mode 4: Forced Charge/Discharge (Manual Override)**
* Operation: Manually force the battery to charge (from grid/solar) or discharge to power loads. Use sparingly and only if necessary.
* Use Case: Preparing for a scheduled outage or testing the system.
7.0 Shutdown and Startup Procedures
7.1 Full System Shutdown (For Maintenance)
1. Turn off AC load breakers (to the house circuits/backup panel).
2. Turn off the AC input breaker (from the utility grid).
3. Turn off the DC isolator switch for the solar array (on the DC combiner box or near the inverter).
4. Turn off the DC isolator switch for the battery bank.
5. Power down the inverter using its internal soft-off switch (if available). The unit is now fully de-energized.
7.2 Full System Startup
Reverse the shutdown sequence.
1. Ensure all AC and DC load breakers are "OFF".
2. Turn "ON" the DC isolator for the battery bank.
3. Turn "ON" the DC isolator for the solar array.
4. Turn "ON" the AC input breaker (from the grid).
5. Power "ON" the inverter using its internal switch.
6. Wait for the inverter to complete its self-test and show "Normal" or "Grid-Tied" operation.
7. Gradually turn "ON" the AC load breakers.
8.0 Basic Troubleshooting
Symptom | Possible Cause | Action |
Inverter in Fault/Error Mode | Overload, Over temperature, Grid fault | 1. Note the error code from the display. 2. Consult the manufacturer's manual for the code meaning. 3. For persistent faults, contact technical support |
No Output Power | Grid outage (and battery empty), System shut down, Main breaker tripped. | 1. Check if the Grid is down. 2. Check all breakers and isolators. 3. Check battery SOC |
Battery Not Charging | BMS disconnect, Charging settings incorrect, Battery fuses | 1. Check battery communication cables. 2. Verify charging parameters in settings. 3. Contact EVVO Support |
Reduced Solar Production | Dirty panels, shading, inverter derating | 1. Check weather and for shading. 2. Check inverter for derating due to heat. 3. Review historical production data |
Inverter Making Loud Noise | Overloaded, cooling fans at high speed | 1. Check for excessive load. 2. Ensure vents are clear. 3. If noise continues, shut down and contact EVVO Support |