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three phase

  1. D

    Two post carlift single to three phase

    Has anyone had any history of powering a three phase motor from a single phase supply? Is there a preferred/best way of doing this? i.e.single phase to three phase inverter/VVFD, convertor or using capacitors etc. Not my usual avenue, but I have had the question put to me, so I am trying to get...
  2. M

    Using one phase of three phase supply, will rcd work properly?

    I have a property abroad that has just been given a new supply by my local electrician . It has gone from six mm2 single phase supply to 10 mm2 three-phase supply it has a three-phase RCD unit and currently is only using one of three phases The other phases will come into use when the...
  3. S

    Three phase INDUSTRIAL fuse board recommendation

    Hello I have a small industrial unit with a messy distribution board. It has 100A breaker and around 10 circuits (lights, sockets, air compressor, three phase 16A fuse etc....) Can you recommend a quality new board from Schneider Havell or Hager?
  4. T

    Earthing of Three phase Motor

    Hi recently was on a job carrying out EX inspections on three phase motor at a pharmaceutical plant. The supply cable going to the motors does not have a core for the earth they have used the braid/SWA of the cable for earthing. So entering the three phase motor with EXe cable glands terminating...
  5. SJD

    Single to three phase converter

    One of my customers has a single phase to three phase converter, to power a 3-phase pump. The converter is a rotary type, quite noisy, and recently has been prone to breaking down (three times so far this year). So they are looking for a static or "digital" converter replacement, 230V to 400V...
  6. C

    Three phase - serial connection

    I have two FCU's in the same room. Can these two FCU's (3 phase) be fed from same cable from the panel located in the another room? Is it acceptable as per codes? or do I need to run separate cables?
  7. Spark2019

    Commercial Three Phase Power Supplies

    Hi I'm new to the forum & currently still learning the trade, would someone please be able to clear this up for me as I keep getting conflicting information, my understanding of three phase power supplies is, if you have a standard system in place say TPN supply & 3 x main cut out's, fused at...
  8. A

    Noob Three Phase Help

    Hi Everyone, I'm hoping someone might be able to help answer a question which i have long pondered over. Firstly i am not an electrician, please dont hold it against me, i'm just interested to seek answers when there is something i dont quite understand. I work in the event production...
  9. S

    For Sale [North]: Single Phase & (some) Three Phase Boards & Devices

    Afternoon all, I've had another clear out. I thought I'd offer it up to you guys before I whack it on eBay. I'm ideally looking for an offer on the lot, however i'm happy to take offers to suit what you need. Here's what's available: 1 x Single phase 11 way consumer unit 100 amp incomer -...
  10. J

    Three Phase Rotary Converter Install with Sockets

    Not a 'commercial' job as such but given that three phase is involved I feel it belongs in this section. In my semi-professional cabinet making workshop I have a 32A consumer unit. For a range of three phase machinery I have acquired a Transwave Rotary Converter (RT4) which requires a 25A...
  11. 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...
  12. Michael J

    Three Phase overhead supply is it TN C

    While carrying out a EICR I found on first inspection that there were no RCDs installed . When I checked at the Pole Mounted Transformer the Earth & Neutral were connected at the Neutral point. So am I right in concluding it's a TN-C System? The 17th Edition states that RCDs should not be...
  13. G

    Rear entry three phase board

    Hi, Is it OK to create a rear entry in an eight way three phase BD. A technician friend of mine says he has never seen this done before?
  14. L

    63A three phase socket

    Good morning, We have a load of approximately 18.5kw ( compressor skid). There is a plan to install a dedicated socket for this machine, the cable route is yet to be finalised and One of the contractors says 16mm2 cable 100A fuse is adequate but this comes from a rule of thumb as opposed to...
  15. nicnic66

    Amtech/trimble single phase three phase headache?

    Amtech will not let me record a single phase D.B from a 3 phase D.B for a sub-mains. It keeps saying in a warning message that the installation is 3 phase and it cannot be recorded as single phase even though it will let me record single phase D.B's individually on the board schedules...
  16. L

    Three phase socket query

    Hi, We have a three phase 400v socket rated at 63A. It is proposed to use this for a mobile skid. There is an 18.5kw motor and an approximate estimate of current is 34A, the supplier is saying that the socket is not rated high enough as the skid has dual redundancy ( two 18.5kw motors) and as...
  17. D

    Single to three phase converters

    Has anyone had any experience of using these?? Any good?? Got a customer who wants to put a 3 phase 11kw chicken rotisserie into a shop with only a single phase consumer unit and doesn't want to spend 10 grand on getting a new supply.
  18. L

    Single Phase Load Estimate to Three Phase Power Supply

    Hi Everyone I would be glad if you could clarify this for me: For a Load Estimate Survey whereby 95% is single phase, the Load Estimate is 90 KVA (Single Phase). However, the power supply is three phase 4 wire system. To calculate the current per phase, the 90 kVA is divided by three i.e. 30...
  19. G

    Single Phase Charger on Three Phase Supply

    Hi all, been a bit of a lurker of the forums here for a while and so far they have saved me more times than I can say, but now I have a question that I am hoping you can help me with. I have a single phase forklift charger and it currently has a 2p+e plug and connects to the corresponding...
  20. J

    Domestic three phase? advice

    Hi I have recently moved into a small newly renovated (inc electrics) cottage and noticed appliances going really slow. Kettle taking an age to boil, toaster taking a long time, hair clippers going slow... you get the picture. UK power networks sent an engineer that changed the overhead power...
  21. M

    No neutral on three phase

    Hi all Need some help remembering some college work. Been doing a job and we are pulling in 400mm singles in parallel, got three phases and a seperate earth but no neutral. From what i remember from college was it becuase if you had the phases all balanced youd have no...
  22. P

    three phase coolant pump

    Hi i have just bought a lathe which is running on three phase i have bought a vfd to run the lathe from single phase but i have a coolant pump that runs on three phase i have converted it to run on single phase but it appears to have a dip when running do any of you guys know what i need to do...
  23. C

    Three phase upgrade question

    Hello all...hope someone here can help.... currently have three phases coming in to the property (old farm) but only receive single phase with a single phase meter. The overhead cables were upgraded a few years ago so the cabling up to the meter is all fairly recent, I can see the 3x100amp...
  24. haptism

    NVQ3 2356, three phase question

    I will be enrolling on the NVQ3 2356 soon but have a question regarding the three phase element. As i work for agencys as an improver its seldom that I ever get asked to connect up three phase equipment, or test it. How have any of you previous students on the 2356 (mature candidate) found their...
  25. 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...
  26. S

    Maximum breaker size for DB (solar PV)

    Hi, Can anyone point me in the direction of the regulation / code for the max solar MCB size when connecting into a spare way of a local distribution board ? Eg. Is it possible to connect a 100A breaker into a 100A board ?
  27. RyanAspire

    A slight issue, reassurance wanted!

    [tl;dr] If an item of equipment wanted to draw 16A of current, would it be possible for something else to restrict this? i.e. If equipment wanted to draw 16A of current, is it possible it would only draw 10A (hence making it not operate as it should)? Due to something external of the...
  28. A

    How to determine the Line and Phase current and power of a three phase installation?

    I am attempting to produce a design for a theoretical installation with a three phase incoming supply (presumably Star/Wye with PME to star point), and am having some trouble understanding and determining the current and power of each phase, and the whole installation at the incoming supply...
  29. E

    Help with wiring three phase pool airblower

    hi. one of the electrition in our company tried to wire a three phase pool air blower {in star connection}. when he connected the three phases to the air blower after one minute the air blower coils were burned. the thing is before that there was another of one phase air blower and it was...
  30. M

    Upgrade to three phase supply

    Hi all, Newbie here with no electrical experience so please be gentle! :blush: I am currently refurbishing my basement flat and during this we have discovered that the supply to the four flats is single phase. I have been told this is unsafe and insufficient for the four flats. U.K. Power...
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