Solar Installation Guide
Wiring diagrams, roof mounting steps and hybrid inverter setup — everything you need to understand how your kit goes together before the electrician signs it off.
Before you start
- • Solar strings are live whenever daylight hits them — treat DC as always energised.
- • AC connection to the consumer unit and G98/G99 notification must be done by a qualified electrician.
- • Work at height requires proper access equipment and fall protection.
- • Never connect a battery without the BMS comms lead configured.
Tools & materials
- Cordless drill & impact driver
- Torque wrench (rails and clamps)
- MC4 crimp tool and spanner set
- DC-rated multimeter and clamp meter
- Cable cutters, ferrule crimper, cable ties
- Roof ladder, harness and edge protection
System wiring diagram
A typical UK hybrid solar and battery installation. DC from the array runs through a lockable isolator into the inverter; the battery connects on its own DC port; AC feeds a dedicated way in the consumer unit with a CT clamp on the incoming tails for export monitoring.
String wiring
Keep string voltage below the inverter's maximum DC input at the coldest expected temperature, and keep parallel strings at equal panel counts so the MPPT tracks correctly.
Panel mounting steps
1. Survey the roof
Confirm rafter positions and spacing, check tile condition and plan the array layout leaving at least 300mm from roof edges and ridge.
2. Fit the roof hooks
Lift tiles, screw hooks into rafters with stainless coach screws (typically 2 per hook), then re-seat or dress the tiles so no lift or gap remains.
3. Install the rails
Bolt rails to the hooks, level them across the array and join with splice connectors. Keep rail overhang within the manufacturer's limit.
4. Earth the array
Run the earthing conductor through the rail bonding lugs and back to the main earth terminal. Every rail section must be electrically continuous.
5. Place the panels
Lay panels onto the rails, fit end clamps and mid clamps and torque to spec (usually 12–20 Nm). Leave a small expansion gap between modules.
6. Route DC cabling
Clip MC4 leads to the rails using UV-rated clips — never leave cable resting on tiles. Match polarity and label each string at both ends.
Inverter setup
- 1
Mount the inverter on a shaded, ventilated wall with 300mm clearance all round.
- 2
Connect AC output through a dedicated RCBO in the consumer unit (isolators both sides).
- 3
Land the battery cables — positive and negative to the correct terminals, plus the BMS comms lead (CAN/RS485).
- 4
Connect the DC strings last, with the DC isolator OFF. Verify string voltage and polarity with a multimeter first.
- 5
Energise in order: battery → DC isolator → AC isolator. Then set grid code (G98/G99 UK), battery type and charge/discharge limits.
- 6
Pair the WiFi dongle, register the system in the monitoring app and check import/export readings against the CT clamp.
Prefer us to fit it?
Our engineers handle the roof work, DC/AC wiring, commissioning and G98/G99 notification.