by ericmark »
Fri Apr 22, 2016 12:42 pm
There is a major problem with this forum once posted you have to wait ages to read through what you have posted. It seems you have no pictures and the typo errors mean hard to understand what you are saying.
So just a few pointers. Two way switches as they are called should have three wires plus an earth between the two switches. However there is a method where with twin switches one can "borrow" a line from the other switch and reduce the cable to two wires plus earth.
However this has two major problems, the first is radio interference, the second is the two switches MUST be from the same protection device. Over the years we have scene the raise and fall of the silly 2" spot light, and these were very power hungry. As a result it was common to split the upper and lower floor lighting circuits. This can cause real problems with two way lighting on the stairs.
Before the days of the RCD and RCBO although dangerous and against the rules borrowing neutrals with two way lighting was common. They did not always realise it was a borrowed neutral they thought they had just borrowed a line, but technically they had borrowed a neutral.
As we started to fit RCD and RCBO protection these faults raised their ugly heads and caused no end of problems trying to correct them. Lucky today you can get RF switches, does mean swapping a battery every so often but does mean you can correct the borrowed neutral fault without fitting new cables.
The two way system goes switch to switch and does not normally effect how the rose is wired. The rose has four connections the earth of course and then normally a strip of connectors split 2, 3, 3, which are switched line, permanent line, neutral. The big problem is often the switched line uses a black wire (or blue with new colours) there should be a red (brown) sleeve to identify it as line, but it is often missing. If you get this wire mixed up with the neutrals it is really hard to identify it after.
I may have answered your question, but even if not, it may help you when correction the typo errors.
