How to Wire an FRC Robot: A Beginner Electrical Guide

Wiring your first FRC robot feels intimidating, but the electrical system is really just one chain: battery, breaker, power distribution, and then everything else branching off it. Get that chain right and the rest is repetition.

This guide walks through the standard FRC control system in the order you actually build it, with the real numbers you need to pass inspection. If you want the full lesson set with diagrams and worked examples, the Electrical & Wiring department on LearnFRC goes deeper on each step.

The power chain, top to bottom

Every legal FRC robot runs off exactly one battery: a 12V nominal sealed lead acid (SLA) battery, minimum 17Ah and maximum 18.2Ah, which is why people just call it "the 12V 18Ah battery." It connects through an Anderson SB connector (the pink/red SB50 you see in the Kit of Parts) on 6 AWG leads. Only one battery is allowed on the robot at a time.

From the battery, power flows in this order:

• Battery, on 6 AWG wire, to the 120A main breaker
• 120A main breaker, on 6 AWG wire, to your power distribution device
• Power distribution device out to every motor controller, the roboRIO, and the radio

The 120A main breaker does two jobs at once: it is your master power switch (the button you push to turn the robot on and off) and the main protection for everything downstream. Mount it where a person can reach it easily.

Power distribution: PDH or PDP

The power distribution device is the hub of the whole system. Two are common:

• The REV Power Distribution Hub (PDH), the current Kit of Parts standard
• The CTRE Power Distribution Panel (PDP), still legal and on many veteran robots

Both take battery power in and split it across numbered channels, each protected by its own breaker or fuse. On a PDH, motor controllers land on the high-current WAGO terminals and are protected by 40-amp snap-in breakers. The same connector accepts a range of wire sizes, so always match the wire to the breaker, not the other way around.

Wire gauge and breaker rules that actually get inspected

This is where new teams lose points at inspection. The rule is simple: the breaker or fuse protects the wire, so the wire has to be thick enough for the breaker behind it. The minimums are:

• 6 AWG for everything from the battery through the main breaker to the distribution device
• 12 AWG minimum on a 40A breaker (typical for big drive and mechanism motors)
• 14 AWG minimum on a 30A breaker
• 18 AWG minimum on a 20A breaker

Thicker is always allowed; thinner is never allowed. When in doubt, size up. These requirements live in the robot construction rules of the FRC Game Manual (the R6xx electrical rules), so check the current season's manual before your competition.

Powering the roboRIO and the radio

The roboRIO is the brain of the robot, the computer that runs your code. It does not get its own 40A channel. Instead, you power it from a non-switchable, fused channel on the PDH (channels 20-22) protected by a 10A fuse, using 18 AWG wire into the roboRIO's power connector (red to V, black to C).

The radio is the current Vivid-Hosting VH-109, a Wi-Fi 6E radio built for FRC. There are two supported ways to power it: directly off battery voltage, or through the Radio Power Module (RPM), which sends clean 18V passive Power-over-Ethernet down the same Ethernet cable that carries data. One hard rule: never feed the radio from the RPM and a separate 12V source at the same time, and don't run the RPM alongside a PoE camera on the same radio. Doing so can damage the radio.

CAN bus: the nervous system

Beyond power, modern FRC devices talk to each other over a CAN bus, a single twisted pair (yellow and green) that daisy-chains from the roboRIO through the PDH and every CAN motor controller in a loop. It lets you read motor current, set IDs, and get rich telemetry that simple PWM wiring can't. Keep the chain continuous and terminate it correctly, or devices will drop off the bus.

Build habits that save you

• Color code: red for positive, black for negative, every time
• Strip the right length, crimp firmly, and tug-test every connection; if you can twist a main breaker lug by hand, it's not tight
• Insulate exposed terminals with heat shrink or electrical tape
• Leave a little slack and label both ends of long runs

Wiring is one of the most learnable parts of FRC because the rules are concrete and the same patterns repeat across every robot. Take it one connection at a time and verify as you go.

Ready to go deeper with full diagrams, crimping technique, and rule-by-rule checklists? Start the Electrical & Wiring guide on LearnFRC.