Hi, posting for a friend,
Whilst fitting a LED Light bar ( believed to be 120w) to a Landrover Defender (1995) he tapped into the signal wire of a relay that supplies his roof spot lights and used that as his signal for the light bar relay..
He has used the horns earth for the relay and also...
when working out voltage drop on a lighting circuit to work out the amp's (lb)I don't have a problem, say 10 lights @ 100 watts each 1000 watts 4.35 amps but what should I apply for a ring final and radial circuit.
With reference to Voltage Drop calculations and Table F4(ii) OSG page 151.
When designing an installation the cable is selected, among other factors, so that the maximum operating temperature is not exceeded, in this case 6242Y T&E = 70C.
The table, titled "Voltage Drop (per ampere per meter)...
Hi All,
Could anybody help me to understand the connection between harmonics and voltage drop in multi-core cables. I understand that voltage drop is directly proportional to the load current and length and inversely proportional to the cross sectional area of the cable.
Will the additional...
I have a question in a mock exam paper for the 202 exam.
It asks "Four resistors in series have the voltage drops across them of 37V,55V,19V and 9V. Calculate the supply voltage.
I'm struggling with how to approach this. I know how to work out VD but that requires more information (current)...
hi guys, im having a problem wiring some relays that need to be activated by 2 different signals, i try putting a diode on one of the signal wires so electricity wont flow thru the other signal wire, but now im having a huge voltage drop, and the relay is not activating by the wire that has the...
Hi,
I came across a situation recently while investigating a problem where measuring voltage at a set of 4 sockets read 243 Volts with no load, and when a 21 Amp load is applied, the voltage then reads 230 Volts.
Is it normal to have such a large voltage drop under load? Or does it imply the...
Hi this is my first time on this forum so take it easy please but I'm after a little bit of advice... I wonder if someone can help me calculate the voltage drop of an install that is in the process... I will give you as much info as possible, any help would be greatly appreciated...
.400a main...
Hi All,
Quick brain pick.
If I don't care about voltage drop (eg. all components on the circuit will run between 100-250V) and current capacity is within limits, are there any other considerations when deciding to use a smaller than 'normal' cable size?
200m run - 10 x 300w loads equally...
I have an install to complete where I have to take a 100amps per phase three phase supply over 330m too power a new installation. The power at source is obviously 415v (give or take) however the rating on the machine at the other end is 400v (build in Europe somewhere). I'm currently having a...
Just a quick one folk.
Do the voltage drop tables in the BGB apply for ELV systems?
I'm converting my van to a camper so I'd adding 12v circuits for lighting, water pump etc.
It's all going to be run in 3183Y flexible cable, can I use the VD values per mA/m in the regs, the same way as I...
Hi guys. Those who don't know me I have recently started on my own.
I am testing my understanding, re Volt drop. And trying to stick to one formula. But I'm getting mixed results.
My example scenario would be to feed a CU in an outhouse / shed.
The CU will feed sockets, lights and some form...
Hi,
I am sitting in C & G 94/95 exams on 22/04/2015. i am attempting past papers and got confused regarding some voltage drop questions below:
1.Compliance with the voltage drop for a 230 v single-phase electric Kiln circuit is to be confirmed. The circuit is installed using thermoplastic 70...
Hi,
Am running a radial power circuit in 4mm fp200 with a 20A rcbo but am a bit worried about the voltage drop. I have a 70M run clipped direct and by my calculations I will need to go to 6mm. I am using table 4d2 but don't know if there is a table for fp200.
Can anyone tell me what the permissible voltage drop is for a three phase circuit serving a power circuit. Is it still 5% like for a 230V circuit. I don't have my BS 7671 to hand at the mo. Thanks in advance.
Hi,
I've been doing some revison and came across 2 different equations for voltage drop.
The first one is;
Vd = mV/A x Ib x L divided by 1000
The second one is;
Vd = (R1 + R2) x Ib x Multiplier
The multiplier is to compensate the difference in conductor temperature at the time of the test...
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