what do the M and S represent on the low voltage schematic?

[scssmith]

The low voltage schematic has circled S and M symbols. What do these represent? thanks in advanced.

[azflycaster]

A Circle M is a motor. Not sure about the S. A Circle backwards S is AC Voltage.

[Phoenix]

Can you scan and post a portion of the schematic?

[RBolton]

A/C voltage source symbol can look like this.

It's not a letter "S" but could be mistaken for one.

[eubank]

Seems like our manual includes an "S" symbol as well in the 12v circuit. It means "switch" -- or at least it corresponds in our rig to every point along the circuit that has a switch.
Lynn

[scssmith]

I have attached a file. thanks for the info

[garry]

Looks like a symbol to indicate a switch.

[Phoenix]

I agree that the "S" looks like it indicates a switch and the "M" probably represents the furnace blower motor. However, the draftsman that drew this schematic didn't use standard electronic symbols.

[Aviator]

It is a switch and the M is a motor. A sideways "S" without a circle is a fuse.

[scssmith]

thanks so much for the help!

[HowieE]

I have seen some intentionally confusing schematics, York AC units, in my day but is a close second.

Yes I agree the S, there are 2 leading to the furnace one for the thermostat and one as an on/off switch, is a switch and the M is the fan motor.

The problem is he did not indicate ground on the 12 system and has the 120 volt side drawn a a single line.