3-blade 240VAC Dryer Socket, Where is the Ground or Where is the Neutral?

[raywu1688]

My California dryer wall socket has 3 blades shown in picture. I measured across bottom 2 blades = 240VAC. I measured top L-blade with one of the bottom blade = 120V. Is the L-blade a neutral? If yes, why no Ground blade? If the L-blade is Ground instead, then why no Neutral blade?

I tried testing continuity of the center round hole to a nearby 120V regular wall socket's ground, no continuity = center hole not a ground??

 

[Avo Mk8]

That is an old style socket with a combined earth and neutral pin at the top, as you have discovered by your measurements.
The hole in the middle is not a connection.
,

 

[Megawatt]

My California dryer wall socket has 3 blades shown in picture. I measured across bottom 2 blades = 240VAC. I measured top L-blade with one of the bottom blade = 120V. Is the L-blade a neutral? If yes, why no Ground blade? If the L-blade is Ground instead, then why no Neutral blade?

I tried testing continuity of the center round hole to a nearby 120V regular wall socket's ground, no continuity = center hole not a ground??View attachment 100375

My friend way back in the day they didn’t have ground wire to pull. You have 240 vac from phase to phase and 120 vac to your neutral and it has no equipment ground. The only way to fix it is pull a 4 wire cable to it and change the plug. 2 live, 1 neutral and 1 ground which hooks to the metal of the dryer. Good luck