loop impedance

loop impedance

Recent contents View information Top users
  1. S

    UK Amtech/Trimble - Excessive Earth Loop Impedance on SWA cables

    Hi All, I'm new to Amtech/Trimble and I've been asked to review a model. I'm looking at circuits that are SWA cables using the armour and an internal conductor as the CPC. There are various earth loop impedance errors listed where the Zs at the load end is too high, but what I can tell, Amtech...
  2. M

    G99-SGI-3 4.4 kw set export limit phase to neutral loop impedance test on site

    G99 SGI-3 4.4 kw set export limit phase to neutral loop impedance test on site 0.309 ohms and dno max being 180 m ohms or 0.018 ohms so site reading are well over the top or is this not unuall for 1950 lead cable TN-s
  3. H

    Loop impedance calculation

    Hi all , The measured value of loop impedance for a circuit is 2.4Ω. If the temperature at the time of the test was 20°C and the cable is 70°C (factor 1.2) what is the corrected value. Ze = 0.4Ω: the answer that I got is 2.8 but according to my calculations it would be 2.88 ohms follow up my...
  4. D

    Loop impedance and equipment cables

    Two related questions in 1, if anyone is up for helping! (i) When electricians install supplies, is there anything in the regs that says how many milliohms they need to include for equipment cables? I have been told "no", that the loop impedance is only up to the outlet. Now I am an R&D engineer...
  5. J

    Loop impedance measurement

    Hi, All I have a megger LTW325 and fluke 1664FC to measure loop impedance by using high current mode. But both results are quite different. megger LTW325 is given a value 0.04ohms and fluke 1664fc is given a value 0.12 ohms. Means megger can give a current at 230V/0.04=5750A but fluke is only...
  6. E

    Loop Impedance reading

    Hi I bought a holiday lodge last month and decided to test the circuits to see how they measured. The lodge itself is fed from a central point in the holiday village by a 16mm PVCSWA. The main earth wire terminates into a MET it looks to be a 10mm earth that is crimped onto the incoming earth, I...
  7. T

    Fault loop impedance testers

    Hi just wondering how most are testing fault loop impedance and which testing units are best
  8. R

    The measured value of loop Impedance for a circuit is 2.4 Ohms

    Hello trainee forum thank you very much for letting me in here and as a consequence hopefully helping me to develop my skills and knowledge. I'm currently focusing on the 2391 and have enrolled myself on a course with no previous Inspection and testing experience or Knowledge so I do feel kind...
  9. mak

    Is there a max Zs for lighting circuits?

    I can't find anything related to this in the regs so I probably misunderstood the question. The way I see it the max Zs for any lighting circuit depends on the circuit breaker for that circuit. Say we have a lighting circuit with 100x36W ceiling lights which gives us a load of 16A, we choose the...
  10. Mark Wright

    Max Earth Fault Loop Impedance for OverCurrent Devices Before Amendment 3 and Now???

    Maximum Earth Fault Loop Impedance for OverCurrent Device was calculated 230/(MCB Rating*5) * Rule of Thumb is that correct? And how are they worked out now after Amendment 3?
  11. M

    Loop Impedance tester electrical circuit

    Hi A quick one I was wondering if anyone knows how a multifunction tester performs a loop impedance test. I understand how to perform a test and what the results of a loop impedance test give you in working out your PSCC and earth fault current. I use my Fluke multifunction tester every day at...
  12. R

    Testing Loop Impedance through RCD.

    Hi, installed some circuits in a factory. The circuits were tapped off of a busbar that goes straight to the main switchgear. From this I installed a Chint RCD, which then goes to 2x Chint TP MCB and 1x Chint SP RCD. One of the TP MCB´s goes to red commando sockets and the SP MCB goes to blue...
  13. A

    Earth Fault Loop Impedance Test for lighting circuits

    Hello guys, Do you do Earth fault loop impedance test for lighting circuits during periodic inspection ? do you measure it at the lighting point? what is the percentage of lights you test? Thanks alot in advance
  14. J

    Earth Fault Loop Impedance...

    Hi there, I’m just hoping someone could clear something up for me at all. I’m just working my way through some test questions and I’ve come across one in which isn’t making sense to me. Q. Calculate the maximum earth fault loop impedance permissible for a 30mA RCD used to protect a circuit...
  15. C

    AFDDs are a massive fraud

    Derailed another thread with AFDDs, so I am starting this one. I will simply say that UK RCDs and MCBs provide arc fault protection as is. UL not only knows that, but extensively researched UK power systems in an effort to emulate the very same concept 40 years. One the simply fact (growing...
  16. D

    Megger loop impedance irregularity

    Hi, I have a Megger mft1720 and the low current loop test isn’t working properly. Just wondering if anyone else has had issues? Readings are stupidly high compared to the high current test, and this can be made even worse if there’s an rcd in line......
  17. M

    Excessive earth fault loop impedance

    I work for a hotel chain and recently we’ve had our 5 yearly test they have 8 circuits from our LV panel with excessive loop impedance readings !! So apart from either introducing an rcd or dropping mcb ratings or type is there any other way of achieving satisfactory readings ?? Also if I have a...
  18. S

    Earth fault loop impedance

    Morning all. So just trying to refresh my grey matter but having a biff moment. Earth fault loop impedance with circuits protected by BS EN60898 type B circuit breakers. I know the tabulated values are in table 41.3, but for the life of me I’ve forgotten how to calculate if acceptable or not. So...
  19. LewisM

    6A MCB Tripping on Earth Fault Loop Impedance Test

    Hi, just finished a partial rewire at my sisters house and when testing the two lighting circuits (up&down) the 6AMCB trips for both circuits individually, I thought the MCBs might just be sensitive to the test but the smoke alarm circuit also 6A is fine when testing, R1+R2 and IR test all fine...
  20. Gary Tollison

    Earth fault loop impedance, initial verification, multiple DB

    Hello. Not sure if this is the correct forum to post this in (still trying to work out where the trainee section is). Just been doing some practice fault-finding online. Found this scenario: After doing initial verification on an outbuilding with its own DB, which is supplied from the main DB...

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

YOUR Unread Posts

This website was designed, optimised and is hosted by untold.media Operating under the name Untold Media since 2001.
Back
Top