Ledio, I am unable to access specific photos on Picassahttps://plus.google.com/106982528064073343888/posts
I have downloaded instruction manual for 1755 rocker switch
This is ordinary triple-rocker-switch to control 3 different loads.
It is like having 3 single pole switches and each switch controls a separate light (Load)
This is single pole switch for 120Volt, and not suited necessarily for 240Volt loads.
Switch is not for 3-way application as typically found in hallway where 2 switches control same light.
1) You have 4 wires.
Electricians don't guess, they test.
There are 4 types of wires in 120Volt and 240V household wiring: Hot wire, Neutral wire, Load wire, and ground wire.
Load wire means the wire that connects to switch and goes to Light, fan, motor (load)
Hot wire always connects to one side of switch.
Neutral never connects to switch.
Load wires connect to side of switch opposite Hot wire.
Bare copper ground wire connects to any green ground screw.
2) One-and-only-one wire in each 120Volt electrical box is Hot. (assuming you are not replacing
3-way switch or working with 240V)
3) Separate all 4 wires for testing. Tape tester leads to wood sticks. Turn power ON.
Test each wire to bare ground wire. Tester will light up on Hot wire.
4) Hot is identified. Next, find the neutral wire if it is among the 4 wires.
Test Hot wire to all other wires in box, except bare ground wire.
Tester will light up on neutral wire.
Tester will not light up on Load wires.
5) NOT EVERY switch box has a neutral. Or the neutral wires can be twisted together and covered with wire nut and pushed to back of box.
The neutral may be up in the light fixture. Neutral located in ceiling box is typical with bathroom fan-light-heater combos.
If neutral is not one of the 4 wires, then don't worry about the neutral connection because it will already be wired together.
6) Image of 1755 switch shows 1 screw terminal on the Hot side, so connect Hot wire to this single screw.
Other side of switch has 3 screws for connecting each of 3 Load wires.
Note: Neutral wire is NEVER connected to a switch.http://www.frostelectric.com/WOE-IMAGES/00381764.jpg
7) Since I cannot see wiring project or know what loads or how the testing comes out, I suggest connect the Hot wire to single screw terminal.
And then connect 1 of the other wires to other side of switch. Not a neutral.
Turn power ON, and try switch.
Process of elimination might yield result.
8) Add a comment with more question, and it sends e-mail. I will respond.