LEVEL 3 FAULT 2 - Dimmer switch

[Foxhound]

Hello again,

Sorry to ask again but I've got a fault I need to find an answer to finish off my assignment and despite my best efforts I've been unable to find much information about it.

Lighting 2 -

A two-way lighting circuit installed for 5 years has both two - way lighting switches changed for dimmers and the LIGHTS start pulsating? Need to write the fault out and the how to rectify it.

I'm not working in the field at the moment so be gentle but I just haven't been able to find much for this fault. All I know is that you can only have one dimmer on a two way lighting circuit because of the alternating current and because of the bulbs using thyristors that are trigged relative to the zero crossings of the AC power determines the power level. By changing the phase at which you trigger the triac you change the duty cycle and therefore the brightness and therefore the brightness of the light.

I'm getting a bit confused here how all this comes together to affect the light to make it pulse. I'm assuming that both dimmers are competing with each other and they reacting to the alternating current making the lights pulse.

Any help here to clarify this i would much appreciate it, only my tutor is a bit ---- retentive.

Thanks for your help again (I not its a home work site!!)

 

[chrish_1977]

Some dimmers can work on two way with two, there are also electronic ones now, but you have to have a slave and master for two to work

 

[jeremy]

If this was real life, the first thing that I would check is the type of lamp that is fitted, as early CFLs weren't dimmable. If the lighting circuit was installed 5 years ago, this would coincide with when energy saving lamps were really being promoted.

 

[Foxhound]

Some dimmers can work on two way with two, there are also electronic ones now, but you have to have a slave and master for two to work

Thanks again Chris,

When i came back to the other fault about the ring I realised how stupid i was being. I got confused between a open circuit and high resistance fault. It clearly states in the OSG at the top of page 93 that a finite reading means there is no open circuit. Everyone at college seemed to think it was an open circuit but i suppose it depends on the meter and like you said that is irrelevant because we have a value and must go with that value.

I'm aware of the slave and master s/w I was thinking of using that as means of rectification. I kinda need someone to simplify what exactly is going on between the two lights. It's a power factor issue I'm sure because of the thyristors and the ac wave. Just need a more of way of clearing up so i can understand it better. I'v e looked all over the net and haven't yet found something tangible with that makes me feel confident with.

Thanks again your help is appreciated

 

[Foxhound]

If this was real life, the first thing that I would check is the type of lamp that is fitted, as early CFLs weren't dimmable. If the lighting circuit was installed 5 years ago, this would coincide with when energy saving lamps were really being promoted.

Thanks Jeremy,

I had a read up on the CFLS and your right CFLS weren't originally dimmable. So thats my first port of call thanks. What about the conflicting dimmer s/w's? If lamp isn't at fault? Would installing a master and slave solve that problem?

Thanks again

 

[chrish_1977]

Sorry if I sound mean, but I think you are looking too far into the fault, in dimmers there isn't anything that is serviceable, so if the lamps haven't sorted it then change the dimmer