Not sure if my master switch is original, but it's the type that grounds the battery neg cable to the airframe with what looks to be #6 or so wire. The backside terminals are loose in the switch body - I'd like to replace it. Has anyone switched to a low-current master switch with solenoid on the engine side of the firewall? Seems more conventional than bringing the heavy wire to the panel.
Master Switch
- Thread starter blanducci
- Start date
blimpy
New member
Hoo Boy !
I believe that was only done on really early birds.
The 14-13-2 and -3 certainly have a standard Solenoid ( main contactor) as is
standard in any modern airplane.
I wouldn 't fly in an airplane where all the current is flowing through a panel mounted switch,
and you shouldn't either. Not safe, and not reliable. Chances are that switch was WWII surplus.
Good quality, but nearly un-obtanium now. I remember seeing them in War Surplus Stores when I was
a kid in 1959.
You want all the electricity in the cabin to be fused, and controlled by that solenoid operated
relay on the Other Side of the Firewall ! Even the wire from the solenoid to the switch should be fuse
protected.
The club re-print B-211 of the Cruisair Operators Manual has a good schematic of the electrical system, plus
tons of other basic diagrams and information you need to have.
This is the only "POH" we have for our planes, and as such it should be in the plane all the time.
I have an original in my reference files, and copy with additions I have made added : Weight and Balance Calc Sheet,
Climb and Fuel performance sheet, and an AD Due Page showing each AD and when it is due next.
Hope this helps.
I believe that was only done on really early birds.
The 14-13-2 and -3 certainly have a standard Solenoid ( main contactor) as is
standard in any modern airplane.
I wouldn 't fly in an airplane where all the current is flowing through a panel mounted switch,
and you shouldn't either. Not safe, and not reliable. Chances are that switch was WWII surplus.
Good quality, but nearly un-obtanium now. I remember seeing them in War Surplus Stores when I was
a kid in 1959.
You want all the electricity in the cabin to be fused, and controlled by that solenoid operated
relay on the Other Side of the Firewall ! Even the wire from the solenoid to the switch should be fuse
protected.
The club re-print B-211 of the Cruisair Operators Manual has a good schematic of the electrical system, plus
tons of other basic diagrams and information you need to have.
This is the only "POH" we have for our planes, and as such it should be in the plane all the time.
I have an original in my reference files, and copy with additions I have made added : Weight and Balance Calc Sheet,
Climb and Fuel performance sheet, and an AD Due Page showing each AD and when it is due next.
Hope this helps.
Did some more digging and if the parts manual sch is correct then unless modified all 14-13-2 are flying with the same master I've got. Aircraft spruce does not sell it, but there are some parts suppliers that claim to have surplus available. Next time you are under your panel take a look at your master toggle. Mine has four terminals. Two carry the high current. The battery ground lead passes through the fw and connects to one. The second has an equally heavy gauge wire to a bolt on a panel gusset. This all corresponds to the schematic. Even the wire length and gauge is called out.
I'm not too fond of this scheme, but I guess it's held up for over 60 years.
Maybe some have been modified with contactors?
I'm not too fond of this scheme, but I guess it's held up for over 60 years.
Maybe some have been modified with contactors?