wcalvert
Well Known Member
RV-7
I am building a system based on Nuckolls Z-19 diagram (2 pc680 batteries, 1 alternator, low voltage sensing with automatic Endurance buss backup). B&C external regulator with over volt protection, 55 amp Denso alternator. There is a 60 amp ANL fuse on the output of the alternator.
Aircraft is Dynon equipped, VFR only platform. The display will show voltage for each battery.
The engine is run of the mill IO-360 except for the EFII ignition (no mags), hence the redundant electrical power scheme. Superior fuel injection servo.
So I was looking over the schematic and thinking through failure modes, and it occurred to me that there may not be a need for an ammeter. If the alternator fails, I will get a low voltage warning from two sources. If alternator output is too high, the regulator will shut it down and I'll get a low voltage warning soon enough.
The only use for the ammeter I can see is to monitor the load after start to get a feel for the condition of the start battery... how long it takes to get back to a "normal" charge level. Or a slowly running away overdraw on the alternator (can't think of an example).
I realize that the shunt and accompanying wiring will only be another pound or so, but space on the one Dynon display is limited and will need to be prioritized.
Anyone have another opinion? Ok, that's a loaded question. Thoughts then?
I am building a system based on Nuckolls Z-19 diagram (2 pc680 batteries, 1 alternator, low voltage sensing with automatic Endurance buss backup). B&C external regulator with over volt protection, 55 amp Denso alternator. There is a 60 amp ANL fuse on the output of the alternator.
Aircraft is Dynon equipped, VFR only platform. The display will show voltage for each battery.
The engine is run of the mill IO-360 except for the EFII ignition (no mags), hence the redundant electrical power scheme. Superior fuel injection servo.
So I was looking over the schematic and thinking through failure modes, and it occurred to me that there may not be a need for an ammeter. If the alternator fails, I will get a low voltage warning from two sources. If alternator output is too high, the regulator will shut it down and I'll get a low voltage warning soon enough.
The only use for the ammeter I can see is to monitor the load after start to get a feel for the condition of the start battery... how long it takes to get back to a "normal" charge level. Or a slowly running away overdraw on the alternator (can't think of an example).
I realize that the shunt and accompanying wiring will only be another pound or so, but space on the one Dynon display is limited and will need to be prioritized.
Anyone have another opinion? Ok, that's a loaded question. Thoughts then?