Open/switch on the air-conditioner when we are home.
Which is correct? Open or Switch on?
Open/switch on the air-conditioner when we are home.
Which is correct? Open or Switch on?
The preferred way to say it is "turn on":
Turn on the air-conditioner when we are home.
See definition #1 at http://www.merriam-webster.com/dictionary/turn%20on -
to activate or cause to flow, operate, or function by or as if by turning a control
Electrical circuits are active only when the path of electricity is completely from source to load and back to source e.g. battery to fan and back to battery. By convention, a circuit in which electricity can follow this path is "closed" and one in which it can't is "open." Usually, closing and opening a circuit is done by a switch but a short can open a circuit as well.
"Close the switch/circuit" is a command to activate a circuit, usually by analogy with the old knife style up and down switches. So, you really can't start something electric by "opening" anything.
Most phrases for activating a circuit appear to arise from the mechanical motion of switch used to close the circuit. "Turn on" is from a rotary switch which itself probably originated with ball valves on gas appliances that let gas flow depending on on the whether the valve handle is turned parallel in line with the flow or perpendicular to it. There are also flip switches so you can "flip on" a circuit. I suppose with the new touch interfaces, some kid will get told to go "stroke the AC."
If you have someone saying "open" an electrical device, they are probably preserving an archaic analogy to some gas operated device e.g. you could "open" the valve on a gas heater to start it.
In the case of an air conditioner, it's probably a transference from "open a window."
I'd never really thought about this but now I have I would...
Turn on the TV
Switch on the kettle
Open the air-con
Start the car
All done by flicking a switch or pressing a button.