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  1. R

    3 wire Delta calculations

    I have a question on 3 wire Delta connected winding with Phase Supply between X, Y & Z is 370 Volts. What is the voltage between One Phase 'X' and the center tap of the opposite winding? See attached doc.
  2. M

    delta transfomer current

    Hi All, anybody know the formula to find current on delta transformer?
  3. H

    two motor star delta

    hi guys i have an issue with one of two motor running star delta for a concrete mixer one motor is pulling out more current than the other one almost 10A difference (1st=39 , 2nd=48) knowing that the 2nd is rewinding both motor are same company
  4. Michael J

    The maximum value for Zs on a TT system is 50/I delta. So for a 30mA RCd is 1667 ohms

    why is this not the case if the final circuits on a TN-S or TN-C-S system are protected by a RCD? Funny what you think of when you can’t sleep
  5. Amnesh Singh

    Connections of a Three phase Motor STAR and DELTA. 1.0

    Well You all guys know how a Star Delta Motor Works, In Case Some New Sparks in the Electrical Industry wants to know they can download or follow this simple Diagram of a Three Phase Motor. It Tells Both DELTA and STAR Connections of the Motor Windings. I will soon put a wiring diagram of Star...
  6. R

    Lower the voltage of a three phase 220v delta wiring system with auto transformers

    Hi all, I have a three phase 220v delta wiring system but the real voltage is about 240-245V by measuring between the pairs RS, RT, TS. I want to lower it to about 220V so I was thinking to use three auto-transformers 240-220V wired like this: I expect to find 220V between the transformer...
  7. V

    3 phase immersion heaters in star (no N) or delta

    Hi all Been to a micro brewery today . They have 2 water boilers with 3 phase immersion heaters in them (ie 3 x elements) Originally they were wired to run single phase will all the lives and neutrals linked out and a 32A single phase supply connected to them. Now they are wired in a star...
  8. I

    Star Delta motor problem.

    So I have a 55kw Star Delta starting motor. The motor was moved about 10feet from original position so I had to put new cabling in from Isolator to Motor. That's all was changed. When I went to start it it blew a fuse when kicking into Delta. Changed fuse and it happened again only this time it...
  9. T

    Calculation of capacitor value for conversion from star to delta

    Hi does anyone have a notion of how to calculate the capacitance value for the above?
  10. dlt27

    Motors and Star Delta Question

    Hi and thanks for any replies. I am predominantly an install electrician and don't have a lot of experience dealing with motors so any help would be greatly appreciated. I have been asked to connect a CNC machine, a dust extractor and a pump. The CNC is straight forward as it is just connected...
  11. T

    Control Panel Star Delta Starter

    Hello all. I’m after a bit of advice. Daft question I’m sure but when wiring a star delta starter in a panel is it necessary to use the electrical interlocks, i.e for the coil of the delta contactor, would you take the wire through the N/C of the Star contactor first?
  12. M

    How to on & off the dol or star delta motor with timer?

    Hey guys...... I am new to this forum. I looking for a solution since a week but i am not able to get it. I want to switch on & switch off the dol or star delta motor with timer (Please note: here i am not talking about a timer switch which is used to switch the motor from star to delta). I...
  13. Jim90

    Help with 3 phase star delta motor

    Hi, I've been sent on a job to investigate a fan not working correctly. After investigation found that the fan doesn't run in 'Auto' or 'High speed' and just shows 'trip' on the control panel. The fan will run in low speed. I've replaced the belts on the fan as they were frayed. Opened the...
  14. Simon-0116

    3ph star delta starter motor drawing high amps

    Star delta starter / motor problem. Starter starts runs as should on bench with no motor connected. Getting 230v to e on all 6 uvw 1s and uvw2. 415 u1 to v2 etc etc. But nothing 1 to 2s. As expected. When motor connected up. (Single speed) it takes 3a in start on all . Drops into run fine but...
  15. A

    Question regarding 400V three phase lighting connected in Delta, without Neutral.

    I am in the process of designing the electrical installation of a community centre, and have a question about the provision of three phase lighting for a large function room containing 18 36W LED fittings. All of the light fittings are to be switched simultaneously. Would it be possible to...
  16. K

    Star delta testing help needed

    Hi I need some help I haven't work on star delta motors since my 1st year apprenticeship. How do you test the motor from the panel i.e check that the windings are balanced? Any help much appreciated
  17. S

    Delta-Wye Transformers

    Hi Guys, I'm looking for some information or diagrams on Delta-Wye transformers. Most diagrams that I have got, give me information for 3 lines to a Delta configuration then on the secondary side you get the Star configuration. I am really happy with the above concept, I would like to...
  18. G


    Where would a Dd0 transformer be used in the UK? Or an IT supply outside of medical for that matter?
  19. T

    Star Delta motor into DOL starter?

    Hello everyone. I have a new star delta pump (7 core flying lead) that has to be made off into a DOL single contactor starter. Is this possible and does anyone know how?
  20. E

    20 Kva Magnetek Jefferson 60Hz 3 Phase, 460y/260 Dry type transformer

    Hi. Have back fed this transformer trying to achieve 400 volts from a 250 volt 50Hz 3 phase 20Kva diesel powered generator. Have linked the high voltage Delta connected side to include all the windings, and connected the generator to the star connected low voltage windings, leaving the neutral...
  21. UKMeterman

    HV phase lost, strange voltages on LV side

    Hi, Storme Katie dislodged one of the HV jumpers on the DNO 11 KV network, so the local 11KV 415 transformer was single phasing. I expected to get 240, or 120V but there were some people getting 150V and I got about 70 volts and it was indepenent of load. I am trying to work out why not 120V? Thanks
  22. Lee Gold

    Star and delta phase voltages

    I came across a question today in my paper asking me to draw out star connection and a delta connection and draw out phase voltages on star from phase to phase and write in the voltage and I don't understand it at all can somebody help please. Star carrying 240/400v delta 400v Sorry I'm not...
  23. I

    3 Phase presentation

    HiForum Thisall came about as I am looking to use a 3 phase motor with variablefrequency drive/VFD and started to get confused with 3 phasevoltage. MyVFD uses one phase and neutral on the input and presents 3 phases onthe output in Delta (no neutral). At first I though I could simulate400V 3...
  24. Tiny Spark

    A strange fault and a interesting days fault finding....

    Ive had a amusing days fault finding today, Found several faults but have come out of it asking more questions than I have answers. So Me and a colleague go to this AHU that keeps tripping for unknown reasons, The pannel has been canabalised and the inverter and motors covers are removed but...
  25. E

    Do RCCD's work in two phase systems

    Hi, I'm a newby hear and wonder if anyone can help me with this question. I work on a ship and our sockets are 2 phase 220volt instead of Live and Neutral 220volt, i.e we do not have a star point at our transformer. Our network voltage is 11KV / 440v Delta / Delta and then transformed down to...
  26. M

    Delta training/NU Training/ New Delta/Tom Harvey

    Hi guys, I was with delta doing my NVQ and tore recently a guy called TOM HARVEY contacted me and has continued my NVQ. Everything has been fine but now it's time to issue the cert, I just can't get hold of him. I've tried ringing his mobile left emails and voicemails but to no avail! Can an...
  27. infinity

    blackest panels

    Have you found a panel blacker than the penlight delta black? How black are the sun power signature blacks? does anyone have a photo of them? or even a data sheet? I can't seem to find the data sheet for them anywhere just for the normal 327W panel. Are there any other completely black panels?
  28. C

    3 phase motor star delta staring controls

    Hi guys with the star delta motor starting controls I know you have 3 contractors, the main, the star & then delta. The star contractor is looped out as star configuration at the top but I cannot see how the delta contractor is configured in delta, it just looks like a standard contractor to me...
  29. timo1

    Delta training gone under!!?

    Fab. 87% into my nvq 3 and get an email telling me delta have gone under. Have to contact the company tomorrow to see what happens now, but I am getting the sinking feeling that I'm going to be kissing my hard earned goodbye. Luckily paid by credit card so may be protected, but still a pain in...
  30. H

    Delta Training

    I've just been informed that Delta training have gone into liquidation. I had an open portfolio doing the 2356. Liquidator has told me there is next to no assets and I'm set to lose my £800 fee.
  31. G

    3 phase motor

    I wired a 3 phase motor for a hydraulic pump up today. Its a 3kw motor. My boss told me to wire it as a Direct online in Delta. I thought maybe it would be better as a Star Delta as the pump would be dry and it may cause high start up current. I belief that a small motor is fine as a DOL. When i...
  32. T

    JIB Electrotechnical Certification Scheme (ECS) Another jib thread - sorry!!!!

    There's thousands of posts on this but i cant seem to find anyone in my particular situation, and I have rung the jib but as rear usual they give conflicting answers so here it goes, im after the elusive gold approved card my quals are: 2330 lv 2 2330 lv 3 17th (haven't taken the amendment)...
  33. T

    3 Phase Calculations for Star and Delta

    Hi All just a question for the more mathematical people. Have got three 15kw water heaters wired in Star . What is the current calculation for this per phase and would this change if wired in delta assuming a pf of 1 ? Regards John :6::rolleyes2:
  34. G

    remote switching between star and delta (both ways)

    Hi all, I apologise for jumping straight in with a new thread asking questions. I did search and can't find any info on my problem. Getting to the point... I have fitted an ABB EXE2S star delta starter to run a 3phase 15kw motor on an extraction fan. The starter is working perfectly but the...
  35. I

    Power rating - mixed star/delta/single on one board

    Hi, I am required to put data labels on the equipment I manufacture (if anyone knows the reg number of it that would be helpful). One one box on the data label I am required to put the 'KW' rating. Only problem is a few devices I build contain distribution boards and sockets. The maths is...
  36. I

    Commercial Power rating - mixed star/delta/single on one board

    Hi, I am required to put data labels on the equipment I manufacture (if anyone knows the reg number of it that would be helpful). One one box on the data label I am required to put the 'KW' rating. Only problem is a few devices I build contain distribution boards and sockets. The maths is...
  37. V

    high readings on RCD test

    I put two new spikes on a tt system and I am now getting a reading Ze-84ohms, I put new 30Ma trips on three boards but ,I am getting high tripping times on two of the RCD would this be the trips or would there be some other reason?
  38. L

    3 phase motor connection type???

    Hi Guys, I am now working in a industrial environment as an Electrician having spent the majority in a domestic or commercial environment, I have done installation work with 400v 3 Phase however I am a bit rusty on the STAR / DELTA 'meaning' on the id plate of the motor. What my question...
  39. O

    has anyone used delta training?

    has anyone used delta training for there online nvp3? and did u think they Where any good?
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