3.0 3. Electrical System

AC Power System (Mains Side)

Supplies power to the air pump and the AC-to-DC power supply. This section contains mains voltage and must be enclosed.

AC Power Wiring

AC LIVE → Fuse → Split
                 ├→ Relay COM → Relay NO → Pump LIVE
                 └→ Power Supply (L)

AC NEUTRAL → Split
               ├→ Pump NEUTRAL
               └→ Power Supply (N)

AC GROUND → Split
              ├→ Pump chassis
              └→ Power Supply ground

Safety Requirements

• unplug before wiring
• use insulated connectors
• enclose all AC wiring
• verify all connections before powering
• if you are not comfortable working with mains voltage, have someone experienced review your wiring before applying power

Low Voltage DC System (12V & Logic)

+12V →
  → valves
  → relay coil
  → buck converter / regulator input

regulated output →
  → ESP32
  → sensors
  → optional low-voltage UI parts

GND → common ground bus

Grounding

All DC components share a common ground reference.

Powering the ESP32

The ESP32 must never be connected directly to 12V.

Using a buck converter

1. connect the buck converter input to +12V and GND
2. power the low-voltage system
3. measure the output with a multimeter
4. adjust the converter to 5.0V
5. power off
6. connect the regulated output to the ESP32 5V input
7. power on again

Always verify voltage levels with a multimeter before connecting sensitive electronics.