Electrical circuit breaker planning 4

This is an update of

https://webuildplanes.com/adam-dickson-sling2/p/7032/electrical-circuit-breaker-planning-3

where I have cleaned up the backup functionality

Incorporates

18 May 2026

further refinement of the nav/strb functionality

merge separate landing and taxi breakers into one

The breaker size is matched to the smallest AWG-dependent current limit of any one branch off a given breaker or split downstream of a breaker. Current limits are taken from Table 11-3 on page 11-15 in AC43-13-1B:

• 22AWG - 5A
• 20AWG - 7.5A
• 18AWG -10A
• 16AWG - 15A
• 14AWG - 20A
• 12AWG - 30A
• 10AWG - 40A
• 8AWG - 50A
• 6AWG - 80A
• 4AWG - 100A

Breaker sizes inferred from the above table are overridden lower by any stated by Dynon, or by current limits of any interconnects

Left hand group

Bat/Alt master switch (progressive type)

"Fuel pump" switch (SPST) with integral breaker - 5A => TE W31-X2M1G-5

Right hand group

Switches (9 in all):

"EFIS PWR" switch (progressive type) which can select between the main bus and backup battery output, progressive type

"AVIONICS PWR" switch (progressive type) which can select between the main bus and backup battery output, progressive type. The following are all on the "avionics" bus

• radio
• transponder
• flarm/backup EFIS
• flaps
• trim

"LAND" switch (progressive type) sharing breaker with "TAXI" (with 3rd position for wig-wag)

"TAXI" switch (SPST) with sharing breaker with "LAND" switch

"STROBE" switch (progressive type) with positions for tail strobe only, and wing and tail strobe together

"NAV" switch (SPST)

"CABIN LT" switch (progressive type) and dimmer with separate breaker

"AUTO PILOT" switch (SPST) and separate breaker

"USB" switch (SPST) and separate breaker

Breakers (15 in all):

"EFIS" - 2x22AWG ~ 20 AWG 7.5A overridden by Dynon schematic 5A => Klixon 2TC2-5

"AV/EFIS MAIN" use 16AWG wire (wire limit 15A) - Klixon 2TC2-15

"COMMS" - 20AWG 7.5A overridden by Dynon schematic 5A => Klixon 2TC2-5

• Com Radio control panel
• Com Radio

"AV/EFIS BACKUP" - IBBS backup output breaker 10A (limited so as to not exceed the 10A blade fuse and DB15 pin limits) - Klixon 2TC2-10

"XPONDER" breaker 22AWG 5A overridden by Dynon schematic 3A => Klixon 2TC2-3

• Transponder
• ADS-B receiver

"BACKUP CHARGE" - IBBS charge breaker (20 AWG wire limit 7.5A) but overridden to 5A by the IBBS manual - Klixon 2TC2-5

"FLARM/SEC EFIS" breaker 22AWG 5A overridden by Flarm manual 3A => Klixon 2TC2-5

• Flarm fusion
• Flarm trafficView80
• Kanardia Horis

"USB" breaker - 18AWG (10A wire limit, 7.5A pin limit) => Klixon 2TC2-7.5

"FLAPS" breaker 20AWG (7.5A wire limit) but actuator current is small => Klixon 2TC2-3

"LAND/TAXI" breaker shared breaker for the landing and taxi lights (13A pin limit, 13A wire limit) => Klixon 2TC2-10

"TRIM" breaker 22AWG - 5A wire limit but current draw small => Klixon 2TC2-2 (because a 1A popped)

"AUTO PILOT" breaker 20AWG lines (7.5A wire limit) with 22AWG at the motor (5A wire limit) combined into 18 AWG => Klixon 2TC2-5 (above maximum draw of autopilots which is 4A combined)

"NAV/STROBE" breaker 18 AWG wires, 7.5A size 20 pins shared for the strobe and nav lights => Klixon 2TC2-7.5

"HEADSET" breaker 20AWG 5A wire limit but current draw tiny => Klixon 2TC2-1

"CABIN" breaker 22AWG 7.5A wire limit but current draw tiny => Klixon 2TC2-1

Summary

2 x Klixon 2TC2-1

1 x Klixon 2TC2-2

2 x Klixon 2TC2-3

5 x Klixon 2TC2-5 (have 2 already)

2 x Klixon 2TC2-7.5

2 x Klixon 2TC2-10

1 x Klixon 2TC2-15

4 x AN3021-2 / MS35058-22 (SPST: on-none-off) - for most on/off switches

1 x MS35058-27 (SPDT: on momentary-off-on momentary) - for flap control

6 x MS25201-4 (Eaton 8860K4) progressive switches

1 x TE W31-X2M1G-5 switch/breaker

15 breakers in all

10 switches in all

1 switch/breaker