Why the rules exist#
The FRC Game Manual, Section 8 (Robot Construction Rules) defines what a legal robot looks like electrically. Inspectors check these at every event, and a non-compliant robot cannot compete. The rules exist for safety (180A+ batteries are dangerous) and fairness (everyone uses the same power budget). The R-numbers below reflect the 2025-2026 manuals; verify the current year's numbering and text each season - electrical rules change.
The key electrical rules#
R601 - Exactly one non-spillable SLA battery, 12V nominal, 17-18.2 Ah, nut-and-bolt terminals, vents unobstructed (2026).
R604 - Charge at 6A average or less; chargers over 6A are banned in pits.
R606 / R607 - Battery must be secured; all battery/breaker terminals and connections fully insulated.
R609 - Main power path (battery, Anderson SB connectors, 120A breaker, PD) wired with 6 AWG copper or larger; names the legal 120A breakers (Cooper Bussmann CB185-120/CB185F-120/CB285-120/CB285F-120/CB285120F or Optifuse 153120/253120) and legal PDs (CTRE PDP, CTRE PDP 2.0, REV PDH, AndyMark AMPD).
R610 - One breaker/fuse per circuit (except the roboRIO/radio circuits in R615/R617).
R611 - The robot frame must not carry current - electrical isolation required between the electrical system and the frame.
R612 - The 120A main breaker must be quickly/safely accessible from the exterior; it is the only 120A breaker allowed.
R614 - Custom circuits limited to 24V (with a COTS PoE exception).
R615 - roboRIO power must connect directly to a non-switched, protected PD output terminal pair with a 10A fuse or breaker, with no other load sharing that circuit (the rule is written generically for any legal PD and no longer names specific terminal numbers).
R616 / R617 - Radio power: for 2026, VH-109 radios must be powered directly from a PD via passive PoE on the RIO port and/or the 12V input - VRM and RPM are no longer legal for powering the VH-109 (they remain legal only for OM5P radios at China events).
R618 - One wire per PD terminal - splice multiple wires into a single lead.
R619 - Only approved breakers (Snap-Action VB3/AT2/MX5, REV ATO, CTR ATO, ATM), all 40A or less.
R620 - Only approved fuses (ATM/ATC/ATO blade fuses) at the specified values.
R621 - Each branch protected per Table 8-3: motor controllers/custom circuits up to 40A; relays/PCM/PH/servo up to 20A.
R622 - Wire gauge by current (Table 8-4): 12 AWG (31-40A), 14 AWG (21-30A), 18 AWG (6-20A / 11-20A fuse), 22 AWG (motor power adapter boards, ≤5A breaker, ≤10A fuse), 28 AWG (signal-level circuits incl. CAN).
R624 - Color coding: positive = red/yellow/white/brown/black-with-stripe; negative = black/blue.
R626 - VH-109 PoE passthrough rules; the radio 12V input must be wired with 18 AWG or larger.
R709 - Robot Signal Light (RSL) required: one or two diagnostic RSLs (P/N 855PB-B12ME522 and/or am-3583), connected to the roboRIO 'RSL' terminals; if using the 855PB, jumper it for solid-light operation.
Passing inspection#
Build to these rules from day one rather than fixing violations at the event. Common inspection failures: missing/incorrect RSL wiring, undersized wire, multiple wires in one terminal, an inaccessible main breaker, an outdated radio power path, and uninsulated battery terminals.
Sources#
the part worth keeping
Key takeaways
- Section 8 (R601-R626, R709) defines the legal electrical robot, checked at every inspection.
- Core rules: one SLA battery (R601), 6 AWG main path (R609), 10A roboRIO/radio circuits (R615/R617), one wire per terminal (R618).
- For 2026, R616 removed the VRM and RPM as legal radio power; R609/R619 added AndyMark PD and CTR breakers.
- The RSL is required and wired to the roboRIO 'RSL' terminals (R709, P/N 855PB-B12ME522 / am-3583); R-numbers change yearly - re-check.
Electrical & WiringConnections, Rules, and Troubleshootinglesson 2 of 4
Keep going
Take the quiz+10 XP with an accountMore in Connections, Rules, and Troubleshooting
where this came from
Sources and corrections
This lesson is AI-assisted: drafted from primary sources, then reviewed and edited by hand. Errors still get through. When one is reported we fix it and write down what changed, in public, in the corrections log.
sources and further reading
- firstfrc.blob.core.windows.net2025 Game Manual Section 8
- firstfrc.blob.core.windows.net2026 FRC Team Update 00
clipped to this lesson
Articles that go further on this
The lesson gets you through the topic. These go wider on it, and they read in one sitting.
- 5 min readHow to Wire an FRC Robot: A Beginner Electrical GuideA beginner-friendly, accurate guide to wiring an FRC robot: battery, 120A breaker, PDH, roboRIO, radio, CAN bus, and the wire-gauge rules that pass inspection./blogread it
- 19 min readFRC PDH: The Power Distribution Hub Explained (Channels, Fuses & Wiring)A complete guide to the REV PDH (Power Distribution Hub): all 24 channels, breaker and fuse sizing, clean wiring, the switchable channel, CAN telemetry, and PDH vs PDP./blogread it
- 13 min readFRC Robot Radio & Networking: Setup, IP Addresses & the 2026 Wiring ChangeSet up your FRC robot radio and networking right: the VH-109, the 10.TE.AM.x IP scheme, the 2026 direct-wire power change, and fixing connection drops./blogread it
answer sheet
Lesson quiz
All 3 right completes the lesson. Miss one and only that question comes back, anything you already answered correctly stays banked.
0 of 3 answered
01Per FRC rule R609, the battery, the Anderson SB connector, and the main 120A breaker must be connected with what minimum wire size?
02What is the maximum rating of a circuit breaker allowed in a branch (channel) of the PD under FRC rule R619?
03What does FRC rule R601 require about the robot's battery?
Answer every question to submit.
All 35 lessons in Electrical & Wiringopenclose
01 / prerequisites
02 / control-system-components
03 / power-battery-breakers
04 / motor-controllers-can-bus
05 / connections-rules-troubleshooting
06 / worked-examples-mini-projects
- Not read yet:Mini-Project 1: A Single-Motor Test Stand from Battery to Spin
- Not read yet:Mini-Project 2: Current-Limited Drivetrain (CTRE and REV)
- Not read yet:Mini-Project 3: A Live Power-Monitoring Dashboard
- Not read yet:Mini-Project 4: A Switchable Channel for Lights and Vision
- Not read yet:Mini-Project 5: CAN Device Bring-Up with Tuner X and the Hardware Client
07 / common-mistakes-troubleshooting
08 / advanced-techniques-case-studies