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.
- Verify battery voltage: For a 48V system, connect four 12V batteries in series (total 48V). Measure with a multimeter to confirm.
- Install DC breaker: Place a DC circuit breaker between the battery bank and inverter. Size it at 1.5x the maximum charge/discharge current.
- 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.
- Polarity check: Triple-check positive and negative before connecting. Reversed polarity will destroy the inverter instantly and is not covered by warranty.
- Tighten connections: All cable lugs must be crimped properly and terminal bolts tightened firmly to prevent arcing.
Step 3: Solar Panel (PV) Connection
- 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).
- Install DC isolator: Place a PV DC isolator between the panels and inverter for safe maintenance disconnection.
- Connect PV cables: Use proper solar cable (UV-resistant, rated for outdoor use). Connect positive and negative to the marked PV input terminals.
- 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
- Close the battery DC breaker first (this powers the inverter)
- The LCD screen should light up and display status information
- Navigate to settings and configure: battery type, charging parameters, output source priority
- Close the PV DC isolator — solar power should begin charging batteries
- Turn on a small test load to verify AC output
- Gradually increase the load while monitoring voltage, current, and temperature
Frequently Asked Questions
Common Axpert installation questions.
Frequently Asked Questions
What battery cable size do I need for the Axpert?
For a 48V system: 3 kW Axpert uses 16-25 mm2 cables, 5 kW uses 25-35 mm2, and 8-11 kW models require 35-50 mm2. Keep cable runs under 1.5 meters if possible. Longer runs require thicker cables. Always check the installation manual for your specific model, as undersized cables cause voltage drop, efficiency loss, and fire risk.
Can I connect the Axpert to a generator?
Yes, most Axpert models have an AC input that accepts generator power. Configure the input voltage range to match your generator's output (generators often have wider voltage variation than grid power). Set the charging current to not exceed 80% of the generator's rated capacity. The Axpert will charge batteries from the generator and switch to solar when available.
What happens if I connect the battery with reversed polarity?
Reversed polarity will destroy the inverter's input protection circuit and potentially the main board within milliseconds. This damage is not covered under warranty. Always use a multimeter to verify polarity before connecting. Some Axpert models have reverse polarity protection, but this should be considered a last resort, not a primary safety measure.
