Hi Folks
I've been trying to work out whether a doorbell will work with approximately 16m run of bell wire. I've tried to find out volt drop, resistance (to calculate volt drop), or even CSA of typical bell wire. But no luck. I tested an approx. 3m length with my MFT and got 0.87 Ohms. That gives 4.64 Ohms over 16m which is almost 40% of 12V (assuming 1A load)! What makes me question this is that by the same logic even a 9m run would give over 20% volt drop and I have wired doorbells with this sort of length before and had no problem.
If you are wondering the bell wire I have is figure of eight from TLC: Twin Fig 8 Bell Wire Solid 100M - https://www.tlc-direct.co.uk/Products/CABELL.html .
What am I doing wrong here? Is bell wire all the same in terms of CSA, resistance and volt drop and if so what is the maximum length? If not, where do I get the figures and how do I calculate it?
I've been trying to work out whether a doorbell will work with approximately 16m run of bell wire. I've tried to find out volt drop, resistance (to calculate volt drop), or even CSA of typical bell wire. But no luck. I tested an approx. 3m length with my MFT and got 0.87 Ohms. That gives 4.64 Ohms over 16m which is almost 40% of 12V (assuming 1A load)! What makes me question this is that by the same logic even a 9m run would give over 20% volt drop and I have wired doorbells with this sort of length before and had no problem.
If you are wondering the bell wire I have is figure of eight from TLC: Twin Fig 8 Bell Wire Solid 100M - https://www.tlc-direct.co.uk/Products/CABELL.html .
What am I doing wrong here? Is bell wire all the same in terms of CSA, resistance and volt drop and if so what is the maximum length? If not, where do I get the figures and how do I calculate it?
