voltage drop

  1. M

    UK Voltage drop and design

    Evening everyone I've a few questions and it would be helpful if someone could answer them but also point me in the right direction for the answers so that I can mark the places for future reference. I've just fitted a small garage unit in a house to allow me to power 3 double sockets in the...
  2. J

    Voltage Drop Design Current?

    When calculating voltage drop and using the formula mV/A/m x Design Current x length / 1000 = v Do I use the design current value after rating factors have been applied? Thanks again for any help.
  3. J

    Voltage drop.

    Can someone clear up a few points for me please. With voltage drop when the voltage is decreased by a % will the current increase to make up for the loss in voltage to give us the same output? And the more current we draw the greater the volt drop? Thank you
  4. tim@fuseboxwal

    Voltage drop under load

    Hi, has anyone encountered a similar fault... TN-C-S supply with old wylex fusebox. Last night, customer experienced total power loss whilst in the shower (electric), nothing tripped and no fuses blown. Customer pulled out fuses to check them and then replaced them all but could only get some...
  5. dokkan1080

    Voltage drop

    Today I saw a swa 2.5mm run from a consumer unit to a garage shed about 45m (eyeballed it) from a 16amp breaker.... to a double socket then a fused spur to a led light fixture. Voltage drop would be : 15X16X45/1000 =10.8volts which complies but I guess its pretty close with power circuits...
  6. C

    Calculating Voltage Drop

    How is voltage drop of a circuit normally calculated in the UK? And why are wires 16mm2 and under listed as a single unit, but 25mm2 and over in R, X and Z? How do I work with Z?
  7. T

    Voltage drop problem not resolved with bigger cable

    Currently working on a job where the client was concerned about the swimming pool heat pump tripping the mcb (the mcb is more than adequate for the job). The heat pump 4kw and pool pump 1.2kw were drawing 27/28 amps with only 197 volts measured at the pump room. It’s about a 60 meter run. I...
  8. HappyHippyDad

    Realistic cable size for voltage drop

    My customer currently has a shed at the bottom of his garden. The shed is approx 70m from the house as it is a huge garden. The shed has electrics going to it. They are from another shed 20m away on a 1.5mm cable. This shed is from a spur off a socket in the house on a 13A FCU. It is 2.5mm. So...
  9. Marcus Vaughan

    Calculating Voltage Drop On Lighting Circuits

    Hello All, I should know this and have been avoiding asking but just want to be sure. So I am designing a downstairs lighting circuit for a domestic refurb/rewire. I reckon max demand will never hit 3 amps. So using the basic formula for voltage drop - (tabulated value x design current x...
  10. C

    Paralleling to reduce Voltage drop

    Hello, can you parallel conductors to reduce Voltage drop? Got a job were voltage drop is an issue and I can't upgrade cables because of cost. Will paralleling conductors of same csa double the csa and reduce voltage drop, and is it allowed in regs?
  11. J

    Having trouble with voltage drop here.

    Hello again. Finding the power I’ve done, finding the current but for the life of me I’m struggling to find the voltage drop across R1 & R2. I’m sure I’ve been doing all the calculations correctly but I can’t end up with 10.11v. It is one of them I’d say once you’ve done it once it will...
  12. charlie76

    Voltage drop in domestic installation

    Without going in to my calculations and design details (just yet), I have a customer wanting a supply to a summerhouse and workshop which is approx 100m from the source. My calcs call for a 16mm² feed to overcome voltage drop, well O.T.T for the required Ib but non the less, what it comes out...
  13. L

    Voltage drop and cable size calculations.

    Hi, would like ta post a question about voltage drop in a cable. If I have a 230v single phase load of 500w with a 50 meter cable run reference method C . What would be the voltage drop in a 1.5mm2 ? From my calculations excluding pf I checked from the table the the voltage drop in mV/A/m of a...
  14. A

    Question regarding Voltage Drop Calculations

    When one is calculating the voltage drop of a circuit, one must determine the length of said circuit. However, I am not sure whether the length of the circuit includes the length of both the Live conductor running out from the consumer unit to the furthest circuit AND the Neutral conductor...
  15. Lexlee

    Fitting led lIght bar - Large Voltage Drop

    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...
  16. P

    Voltage drop on radial and ring

    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.
  17. Pete999

    Pete's Videos Voltage drop explained

  18. G

    Voltage Drop Calculations, Potentially Stoopid Question?

    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)...
  19. S

    Voltage drop and harmonics in multicore cables

    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...
  20. gazdkw82

    Voltage drop - series resistors

    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)...
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