A Few Questions Re; Voltage Drop Etc.

[ICEbear]

[ICEbear]

i can show you a way of achieving 1000 metres without even 1 milivolt in drop

im going to up that to 3000 metres without 0.5 milivolt in drop

[kensplace]

i can show you a way of achieving 1000 metres without even 1 milivolt in drop

im going to up that to 3000 metres without 0.5 milivolt in drop

Tell us more, I cant think of a way to get 1000 or 3000 meters without any voltage drop, not with normal cables anyway..

Perhaps with 3000ft of superconductor... Or shove more than 24v down the line to compensate for the loss, but then you still do have a voltage drop, even if you get the right volts at the end of it, there is still a drop..

Im curious, whats your method that seems to defy the laws of electricity?

[spider]

Hi Ice,I'm not picking on you mate, but volt drop in a cable is due to resistance, however inductance and capacitance also play a part depending on the cable CSA, as kensplace has said, unless you use a superconductor, the current flowing in conductor with a resistance will dissapate enery in the form of heat introducing voltage losses, this is why I'm intrigued.The introduction of capacitors, diode pumps, inverters, step up transformers and any other method cannot defy the physical properties of a conductor, that why I made my comment, I can't see how you can justify your claim to be able to supply a load over 100m with less than 1 millivolt voltage losses, the electrical connections alone could cause that if not made off properly. If you can demonstrate what you claim then I will be off the Dragons Den because you have invented a way to save billions, just imagine, no more overhead lines carrying 400kV, the possibility would be a 3 core flex feeding a city!Sorry to come across as flippent, but by anyones reasoning, your claim is quite astonishing, not saying you haven't done it, but their are at least two in here who would like to know how.Correction to text :1000m not 100m

[ICEbear]

what distances can a 24v supply stretch to without voltage drop?....................not very far if its (DC)

but if its (AC) far very far

[spider]

ICE,

Your theory is flawed mate, with the very greatest of respect, I would reseach further on this.

http://www.tlc-direct.co.uk/Book/4.3.11.htm

[ICEbear]

Hi Ice,I'm not picking on you mate, but volt drop in a cable is due to resistance, however inductance and capacitance also play a part depending on the cable CSA, as kensplace has said, unless you use a superconductor, the current flowing in conductor with a resistance will dissapate enery in the form of heat introducing voltage losses, this is why I'm intrigued.The introduction of capacitors, diode pumps, inverters, step up transformers and any other method cannot defy the physical properties of a conductor, that why I made my comment, I can't see how you can justify your claim to be able to supply a load over 100m with less than 1 millivolt voltage losses, the electrical connections alone could cause that if not made off properly. If you can demonstrate what you claim then I will be off the Dragons Den because you have invented a way to save billions, just imagine, no more overhead lines carrying 400kV, the possibility would be a 3 core flex feeding a city!Sorry to come across as flippent, but by anyones reasoning, your claim is quite astonishing, not saying you haven't done it, but their are at least two in here who would like to know how.Correction to text :1000m not 100m

no probs pal my poor attempt at Humour, no no no i didnt meen there wont be volt drop along the way but did meen there wont be any volt drop at the domes

if its 24vac step-up<-----------------------------3000m---------------------------->step-down

thats why i was trying to find out how many amps at the domes he needed so i could do the Calculations for the 700m

[daubs8]

Well I need 24v AC at each dome so again, the best way of achieving it please? thanks.

[ICEbear]

Well I need 24v AC at each dome so again, the best way of achieving it please? thanks.

ok lets try again (without everybody) picking on mi

24v you need at each dome.

how many amps do these domes need each and how many domes are at the end of the 700 metre run ?

[spider]

Daubs8,

Without going round in cicles, it is recommended that the columns have a 230vAC supply, not only to provide a means to derive 24AC for the dome, but any additional loads that might be required, lighting and detection devices for example, however, to answer your question specifically relating to how far I can run 24vAC, you will have to calculate it as follows:

The volt drop = (mV/A/m) x dome current x cable length/1000

The mV/A/m for a particular cable can be found in 'The On-Site Guide'

As we have already established, all cables will introduce volt drop, if you require 24v at the camera head, either the cable CSA has to be large, or the input voltage has to be high to compensate for the voltage reduction caused by the cable.

Example:

Dome current, say 1Amp

Dome Voltage 24v

Distance 300m

16mm conductor size; 2.8 mV/A/m

2.8 x 1 x 300/1000 = 0.84 v or 23.16 at the head

Same example with 230v:

1.5mm with 8.7v drop (9.2 allowed), I would not advocate the use of 1.5, but is given as an example as why not to use 24v

300m of 16mm is not cheap!!!