Subscribe to to remove all ads and show your support!
  1. F

    Industrial Measuring current using a Shunt Resistor & an Oscilloscope

    Hi people, I'm new using forums for this kind of purposes, so please forgive me if I can't explain myself well, also if this is the wrong sub-forum please tell me ¡. I have to measure the output current & voltage of a High Frecuency, High Voltage transformer, I can measure the Output Voltage...
  2. G

    Single phase circuit on 3 phase system calc

    Hi, I have a query about calculating current in a 3 phase system. So a 22kw load in 3 phase assuming a power factor of 0.8 would be 22000/(1.732x400x0.8) = 39.69A and say a 7.2kw load on a single phase supply would be 31.30A if you simply use ohms law. But what happens when you calculate the...
  3. Diver233

    - Prospective fault current test 2391

    Hello all, I’m now overthinking the - Prospective fault current test for the 2391 practical, the exam boards will be a 3 phase and a single phase board. Do I test the three phase board and double the highest and use that for both DB’s or do I do one for 3 phase db1 and sep one for single phase db2
  4. D

    Industrial ABB VSD Current Draw

    I have specced up a 18.5kw VSD to power a 15Kw pump. On the datasheet ABB ACS580 its current rating is 38A. Should i spec the MCB and circuit etc to 40A or just to the current draw of the motor (around 28A FLC).
  5. A

    Minimizing leakage current

    Hi everyone, I have a problem in a home. By night time his rcd is tripping for no reason. I made and insulation test between neutral and earth + live and earth and got 4 mega ohms. I made a leakage current test and found he have 20mA. Can somone tell me how i can minimize it please...
  6. HoverSPRX

    Commercial Max Demand/Diversity Query

    Hello All, Iv been asked to pick up the remedials on someone else's EICR that was done last year on a school for Deaf Children. One of the items listed on the report is the conductors leading to the sub mains from the main panel are undersized. I popped the cover off to have a look and sure...
  7. L

    RCD RCBO over current

    Hi, I know the basic differences between MCB, RCD and RCBO. I was wandering what happens to a RCD if the current reaches the RCD's limit? Why do RCDs have got ampere rating if they don't protect against over current? In case of RCBO, how do I know at how much ampere they shut down? Is it the...
  8. R

    Zs reading does not meet current regs

    Doing some prior tests befor installing a fused spur from a radial circuit, and have found the Zs reading higher then the current regs, obviously it complys with a past reg, but as I’ll be doing a minor works for the job, when filling out their cert would I just put it down as an observation in...
  9. C

    Current demand & load per phase Q

    Hi all, This is my first post on this forum. I'm currently doing my C&G 2365 and I've found myself completely stumped on a problem that's probably quite simple, but which I've had a lot of conflicting answers for from various people, which has left me a little confused. I'm working on a design...
  10. rustynails

    Current generation under control

    You've all seen people on YouTube overloading twin and earth cables, JW etc... How are they generating current and how are they able to control that generation?
  11. l4urence

    Leakage current meter - recommendations?

    I'm looking at buying something for measuring leakage current - The Megger DCM305e (I think). Not specifically for nuisance tripping but more for DC leakage current - type A vs AC RCD (type AC flooding with DC and not tripping). Not a lot of info on the DC side - except DC units for PV, I...
  12. sam400

    For Sale [South]: Current Regs book for sale

    Blue one for sale in the celophane, purchased from Denmans so genuine book. £50
  13. Vortigern

    Installation is in fair condition and to comply to current Regs would require a rewire/upgrade.

    The above statement was made in an EICR which I was asked to look at. In my opinion they are on the wrong side of Trading Standards to suggest that an installation should be re-wired because it is not up to current regulations. If it is safe then I would not suggest to a client they must have a...
  14. A

    current 2391 course information

    hi, currently doing 2391 course and getting told on a periodic that the only tests you have to do as minimum are zs and rcd, anyone else been taught to do this. tutor shows guidance note 3 and in as way you can relate to it but jut doesn't sound right signing a house off after only being there...
  15. Ewi

    Current draw discrepancy

    Hey all. Im new to this forum. Seeing how limited d web is to rectifying any electrical queiries, i thought i might find this useful. I am a warranted electrical domestic licencee. (Based on IET) and possess a Higher Diploma in Electrical Engineering. I live in Malta (EU) which uses a UK...
  16. happyhippydad

    What can be used to stop back flow of current?

    My friend has a garage door that when opens turns on a floodlight. He know wants it to turn on another light in the garage as well as the floodlight. The problem is this garage light is already on a plate switch, if the garage light was simply connected to the control panel then the plate...
  17. rolyberkin

    Chances of constant current LED's having been fried!?

    Picked up a job where the previous electricians had not connected some collingwood LED stair lights (they were exited from the job!), they had been wired in parallel and no doubt hooked up to an LED driver, anyone up on their electronics? Have they definitely been fried or is it worth taking a...
  18. B

    Commercial Defining what equipment has protective conductor current

    Hi all, I have an engineer who has failed a wall mounted data cabinet because the PDU is hard wired into a switched fused spur, the spur is spurred off a ring main in 2.5/1.5 twin and earth. He has failed it under regulation: 543.7.203 The wiring of every final circuit and distribution...
  19. R

    Measuring current draw by AC motor.

    Hello guys. This isn't a job, just so that you know. Just exploring. I have a couple of AC motors and I am playing with them. One of the things I want to do is measure the current draw. So I attach them to a power source and switch it on and off they go doing their thing. No problem there...
  20. A

    Jumping current on outdoor 12v lighting circuit

    Hello, I have two almost identical circuits of outdoor 12v lighting setup in my garden, each running off a separate 20W 240v-12v transformers (12v Waterproof Transformer (Various Wattages) | 240v - 12v | 10W - 150W -...