Review of master and alternator bus breakers

Using

https://webuildplanes.com/adam-dickson-sling2/p/7174/review-of-standby-bus-breaker-ratings

The total current draw from the following items

• comms
• xponder
• flarm
• backup efis
• flaps
• cabin
• trim
• headset

is 2.345A when receiving, no flap actuations, rising to 6.745A when transmitting and actuating flaps

The total current draw from the following items

• SV-BAT-320
• SV-GPS-2020
• SV-ADAHRS-200
• SV-EMS-220
• SV-AP-PANEL
• SV-MAG-236
• SV-HDX-1100

is 2.96A rising to 3.96A when charging the SV-BAT-320

The total (transmitting, charging SV-BAT-320, and actuating flaps) is 3.96 + 6.745 = 10.705A

The remaining items, not in the above group which can be placed on standby are:

landing lights - 3.4A total

taxi lights - 3.4A total

strobe - pulsed, 3A low duty cycle, ignore

autopilot - 4.06A both operating

boost pump - 1A

IBBS charge current - 4A maximum

USB/camera - 4 outlets, each 5V x 3A total = 15 W ~ 1.25A so total 5A if all in use

Subtotal current 23.8A

Total current 23.8A + 10.7A = 34.5A

Clearly not all these things will be operating at once, in particular the landing and taxi light simultaneously, also the USB

The total current is likely to peak out at about 30A. If the alternator is turned off, then this load will transfer to the battery, so a 30A battery breaker rating seems reasonable, combined with a 40A slow-blow fuse in front of the firewall

In the standard Sling2 design, which has panel power feed, 30A breakers on both the master and alternator are used. I will follow this lead

Accordingly, Klixon 3TC7-30 breakers will be allowed for on the panel.