dimmable light switch problem...help!

[malcmcleod]

i have two light switches operating 7 x 50 watt ceiling spots, in one room. I have purchased a 600 watt, 1G two way dimmer switch to replace one of the two switches, and have wired it up exactly the same as the origonal light switch, but it does not work.
origonal light wiring was brown wire to com,
black wire to L1,
grey wire to L2,
and the earth.
Can i do any damage if i just try changing any two wires around?
P.S. my most adventurous electrical job until today, was changing a battery in a torch...

 

[Adam_151]

did you wire up the dimmer the same way as the other switch was, i.e. brown to com, and the other two wires to the other two connections (doesn't matter which way around)

Silly question, but its probably worth just making sure, you have tried pressing the dimmer knob in haven't you?...

 

[malcmcleod]

yes... the wiring was exactly the same. & i'm sure i tried pressing the knob in, but just in case, i'll try again tomorrow. I popped the old switch back in when it did'nt work and i dare'nt do it when it's dark, just in case i put all the lights out in the street!

 

[malcmcleod]

Have tried re-wiring dimmer exactly same way as old light switch and it definately does'nt work, button pressed in and everything The other switch that controls the light (which is outside the room) does'nt work either, but is ok when i revert back to the old switch again.
Can anyone shed any light on this?

 

[ban-all-sheds]

Are you getting different switch terminal naming conventions mixed up?

Sometimes they are labelled COM, L1, L2, and sometimes L1, L2, L3. If so, the L1s & L2s do not correspond, the equivalences are:

COM <-> L1
L1 <-> L2
L2 <-> L3

 

[malcmcleod]

No, the connections are all similar:-

old switch ~ new dimmer
com(brown) ~ c
L1 (black) ~ L1
L2 (grey) ~ L2
and the earth on both

 

[pdcelec]

How old is the old switch?

 

[malcmcleod]

We've only just moved in to the house, but the previouse owners extended the bungalow with 2 rooms upstairs, roughly about 5 years ago. So 5 years or less, i guess.

 

[pdcelec]

Was it wired at the same time or has there been additions?

 

[malcmcleod]

Not sure i'm afraid. What damage will i do if i try and re-wire by changing two of the wires around?

 

[kendor]

having re read your original post are you saying that there are two switches controlling the spots inside the room with another switch controlling a light outside of the room mentioned in a later post?

 

[pdcelec]

The reason that I asked the age is because the cable colours that you mention are roughly no older than 12 months.

 

[malcmcleod]

The room in question is an upstairs loft conversion in a bungalow. Inside the room there is 1 light switch that controls the 7 ceiling spots. This is the switch that i am trying to replace with a dimmer. Outside this room, there is a small hallway with a double light switch, one switch for the hallway lighting and the other is the second switch for the 7 spots inside the room. This double switch thats outside in the hall, i have'nt touched or even opened up to see whats inside, but when i've tried replacing the other switch with the dimmer, this double switch stops working also.(only the 1 that works the 7 spots that is).
still need help

 

[kendor]

sounds like you've mixed up what your feed is and lost the loop through feeding the other switch hence the hallway doesn't work do you have access to a meter?