Oil Pressure Switch

[asw20c]

For those who installed an oil pressure switch to turn on the Hobbs meter, is this supposed to be a normally open, or normally closed switch? I'm assuming normally open, but you know what they say about assuming...

 

[PaulvS]

Normally open. The switch that Van's sells has terminals for both NC and NO, so you can wire it as appropriate.

https://store.vansaircraft.com/oil-pressure-switch-ie-spdt-pres-15-sw.html

 

[Halleffect]

Analog HOBBS meter?

For those who installed an oil pressure switch to turn on the Hobbs meter, is this supposed to be a normally open, or normally closed switch? I'm assuming normally open, but you know what they say about assuming...

Is this for an analog HOBBS meter? Otherwise, the engine analyzer (at least in Garmin's case) gives you the option to start the HOBBS when the oil pressure goes over 5psi. No need for an extra pressure switch.