How to Install a Voltronic Axpert Inverter: Step-by-Step

Before You Start

The Voltronic Axpert is one of the most widely installed off-grid inverters worldwide. Whether you are setting up a rural home, farm, telecom tower, or backup system, this guide walks you through a safe, professional installation. Important: Electrical installations should be performed by a qualified technician. This guide is for educational reference.

Tools and Materials Needed

• Drill with masonry/wood bits for wall mounting
• Appropriate cable lugs and crimping tool
• Battery cables (recommended gauge per manual — typically 25-50 mm2 for 48V systems)
• PV cables (4-6 mm2 solar cable with MC4 connectors)
• AC output cable (appropriately rated for maximum load)
• DC circuit breaker for battery
• DC isolator for PV
• AC circuit breaker for output
• Earth cable and grounding rod
• Multimeter for verification

Step 1: Wall Mounting

The Axpert should be mounted vertically on a solid wall in a well-ventilated, dry location:

• Minimum 20 cm clearance on all sides for airflow
• Away from direct sunlight and heat sources
• Protected from rain and water splashes
• At a comfortable height for operating the LCD panel (eye level is ideal)
• Close to the battery bank to minimize cable length

Step 2: Battery Connection

This is the most critical wiring step. Incorrect battery wiring can cause fires or damage the inverter.

1. Verify battery voltage: For a 48V system, connect four 12V batteries in series (total 48V). Measure with a multimeter to confirm.
2. Install DC breaker: Place a DC circuit breaker between the battery bank and inverter. Size it at 1.5x the maximum charge/discharge current.
3. Connect cables: Use the correct gauge cables. Keep cable runs as short as possible. Both positive and negative cables must be the same length and gauge.
4. Polarity check: Triple-check positive and negative before connecting. Reversed polarity will destroy the inverter instantly and is not covered by warranty.
5. Tighten connections: All cable lugs must be crimped properly and terminal bolts tightened firmly to prevent arcing.

Step 3: Solar Panel (PV) Connection

1. Verify string voltage: Measure the open-circuit voltage (Voc) of your PV string. It must be below the inverter's maximum PV input voltage (check your model's specification).
2. Install DC isolator: Place a PV DC isolator between the panels and inverter for safe maintenance disconnection.
3. Connect PV cables: Use proper solar cable (UV-resistant, rated for outdoor use). Connect positive and negative to the marked PV input terminals.
4. Verify before connecting: With the DC isolator open, measure the PV string voltage and polarity at the inverter end before connecting.

Step 4: AC Output Connection

• Connect the AC output to your load distribution board through an appropriately rated AC circuit breaker
• Ensure the neutral and earth are correctly connected
• If the inverter has an AC input (for grid or generator backup), connect it through a separate breaker
• Label all breakers clearly for safety

Step 5: Earth/Ground Connection

Connect the inverter's ground terminal to a proper earth rod driven into the ground. This is essential for:

• Personnel safety (electric shock protection)
• Lightning protection
• Proper operation of earth fault protection

Step 6: First Power-On and Configuration

1. Close the battery DC breaker first (this powers the inverter)
2. The LCD screen should light up and display status information
3. Navigate to settings and configure: battery type, charging parameters, output source priority
4. Close the PV DC isolator — solar power should begin charging batteries
5. Turn on a small test load to verify AC output
6. Gradually increase the load while monitoring voltage, current, and temperature

Frequently Asked Questions

Common Axpert installation questions.