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  1. M

    Single phase induction motor schematic

    Hello, I've found an old motor originally designed for operating jealousies. Could you help me read and better understand the following schematic? As far as I understand, it is a single phase induction motor, there is 47 uF capacitor connected to it in order to start. There are 3 contacts...
  2. G

    3 phase shared supply

    Hi all, Im looking for advice about a 3 phase supply. I have such a supply on my property but 2 of those phases are used by adjoining properties that are not mine. Firstly is this "normal"? Secondly is it possible for an increased power load supply in this case? I have contacted northern power...
  3. M

    Industrial 3 phase furnace

    Hi guys, we have a 3 phase 415V 36kw furnace. Just wanted to know the fuse needed for each phase. we put a 40A fuse for each phase and 1 phase just blew when started firing it up. I tried to calculate the right fuse and I come up with 65A per phase? Is that right?
  4. T

    Schneider 63a single phase switch fuse

    Has anyone used a Scheider 63a single phase switch fuse before? Im just wondering whether they need crimped connections or whether its a terminal?
  5. J

    3 phase supply

    Next month i will be working on a farm putting a new 3phase board in to supply welders, plasma cutters etc. 3 phase comes into electric shed (Tnc-s) and then supply into barn comes from 80A 3ph MCB with a 300 ma trip upfront. Supply enters barn and goes into an existing board with the earth path...
  6. D

    3 phase power

    I work in Broadcast television as a broadcast systems designer. I have seen in recent months a trend that is worrying (not sure if it is legal) that in a 19" rack there could be several phases wired to power distribution outlets (normally via IEC connectors) This means it is imperative that...
  7. Midwest

    Supply to 3 phase DB tripped

    As above, place I work at as maintenance, had supply tripped off at the weekend. Not some stuff I’m fully conversant with, so just seeking views here. 3 phase DB supplying power and lighting for rooms, using RCBO’s. Panel has this as main switch; The supply panel is this; From what I can...
  8. Pete999

    Trainee 3 phase infoxxxxxxxxxxxxxxxxxxxxxx

    https://www.youtube.comhttps://www.youtube.com/watch?v=h89TTwlNnpY/watch?v=qthuFLNSrlg https://www.youtube.comhttps://www.youtube.com/watch?v=h89TTwlNnpY/watch?v=qthuFLNSrlg
  9. polo1

    BS number MK 3 phase main switch

    Anyone advise the BS number of this main switch...
  10. A

    3 Phase heating coil

    Hi. I'm making a 3 phase furnace with heating coils. Total power rating is 5 KW. I have to make one heating element for each phase. How do I split the KW rating? Will it be a straight 5/3? Also when calculating the resistance for each heater, should I calculate based on 220V(single phase voltage...
  11. robertl

    Industrial Single phase power all thats avaiable for new workshop build

    Hello Everyone, new to the forum and looking for some advice on a new workshop, i'll explain. I am planning on building a metal / woodworking workshop (mainly aluminium and stainless steel) for boat work, refurbishment and boat building. I am a marine engineer to trade and i am planning on...
  12. J

    9kW 3ph Immersion Type Heater run in Single Phase

    Hi, I received a 9kW 3ph heater from a friend from india, i was hoping to use this in steam production for a distillation project i am working at. I rewired it and made the 3 heating element in parallel connection. Now my problem is the 6 gauge wires i am using are always heating up, also some...
  13. A

    suggestion on using contactor with phase failure

    hi need suggestion on using contactor with phase failure relay to ON a machine which is a cnc router. the cnc router has it self ON and OFF Buttons so thinking to install a contactor with phase faller relay as a power source to machine in case of phase loss the machine power off. currently its...
  14. 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...
  15. 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...
  16. S

    Sleeving 3 phase cable to single phase cable

    Could someone help me understand what is cable sleeving? Can we sleeve a 3 phase cable to single phase cable? Is this as per any regs? BS 7671? Could you send me some pictures of the same if you have..
  17. V

    consumption meter for 3 phase

    hi does anyone know if there is a product please that i can use to meter a 3 phase supply (not current drawn at the time, but one which will continue to add up the current used on each phase). I am after one which will just simply clamp onto the tails rather than hard wire one in. Even if i get...
  18. S

    Electrical test on 3 phase control panel

    Hi i need some advise on writing out a electrical cert for a control panel,i have only tested distribution boards has anyone done certs for control panels?. My query is the panel has overloads for motors,ive done my R1 R2 tests etc how do i record these on the schedule as there not circuit 1-12...
  19. J

    Domestic New Lathe Motor - 1 Phase - DOL or 3 Phase - VFD?

    Hi All, A mate of mine recently acquired a rather nice wood turning lathe they'd like to get running out in their workshop. However he admits his workshop is rather old and while he's not bothered, I'm concerned about drawing too much current (I'm trying to convince him to get the wiring...
  20. westward10

    Phase Guard consumer units.

    Need to do some remedial quotes and the consumer units are noted as Phase Guard. Need some mcbs for them, anyone heard of them or who sold them?
  21. 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...
  22. Z

    Four core or five core for linking outbuildings with 3 phase

    I am laying pipes and cables (separated in accordance with local regulations) underground between outbuildings, and will then close up various trenches. Between one pair of outbuildings I want to connect 3-phase power (they are currently linked by 4 overhead wires, but I have disconnected...
  23. C

    Thermal overload 3 phase to single phase pump

    Boiler panel controlling a 3 phase grundfos pump. Pump was tripping thermal overload... Pump replaced for a single phase grundfos by engineer etc... I was asked to convert the control circuit to single phase which I did. But still tripping on the thermal overload. Set it slightly higher for...
  24. B

    3 phase of 2 phase supply

    Split phase supply L1+L2 on one phase and L3 on another, EB has 3 phase 4 wire incoming but they’ve been out to check and said it’s split phase, what would you put on certificate? 3 phase 4 wire or 2 phase 3 wire?
  25. 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?
  26. C

    3 phase supply to single phases only 2 phases used

    I went to some holiday cottages today, the main supply in was 3 phase however only 2 of the phases were used. The L1, L2 and Neutral cables were wired into a three phase meter, then coming out was L1 and Neutral, L2 and Neutral to create two single phase supplies which were divided off using...
  27. E

    3 phase isolator for a shop/flats above

    Hi All, Have been reading forums for years now,time came to ask for advice. Have a job to fit main 3 phase isolator for a shop with flats above.About to 2 nd fix the flats now,when the supply is sorted.There was a single phase to the flats,done some years ago,without any isolators.Now the...
  28. simpson93

    415v 3 phase sockets and rcd protection.

    Afternoon all, Looking for a little guidance, other than doing sub mains in armoured I don’t do much three phase work. I’m looking to install some final Circuits for some three phase cooking equipment but I find myself stuck on a few things, as the sockets will be over 16amp they will need to...
  29. markthebuilder

    Commercial Split 3 phase across 2 domestic properties

    Hi gents I m looking for info comments advice that will help me look knowledgeable to my boss (money man) northen power grid. & mep consultant . I have been given a project to split 26 student clusters (6 bed) into 54 x 2 bed flats. current supply and metering to each student cluster is as per...
  30. B

    3 phase test readings help

    Hi have wierd dilemma, looks to be 3 phase - 4 wire system so testing am getting this L1-L2 Nothing L2-L3 450v L1-L3 450v L1-N 230v L2-N 230v L3-N 230v Why no L1-L2?
  31. 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...
  32. 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...
  33. S

    Domestic Single Phase Motor Reversing Direction

    Good evening you sparky lot I'm after some wiring advice on an old single phase motor for use on a lathe. Please see the attached pics. The tails have been removed for clarity. Live was connected to terminal B, neutral to AZ. Is it possible to reverse the direction of this type of motor...
  34. P

    Commercial Replacing 3 phase circulating pump

    Hi everyone I have a failed (seized and leaking) 3 phase circulating pump. A direct replacement is well into 4 figures I have a pump that will fit, and has enough flow to do the job, but it's single phase. The supply to the pump is via a contactor, and there is no neutral. Is there any way...
  35. A

    Has anyone seen 3 phase lighting

    Hi new to this, has anyone ever seen lighting on a 3 phase breaker ? A company wanted to use a 5core swa and and share the neutral for using on the other 3 phases, they were told they can’t do this but have now decided to try get round it by using a 3 phase breaker. This is in a 3 phase board...
  36. Y

    Flickering led panel light on 3 phase

    Lights flicker when there is a 3 phase load plugged in. Same lights do not flicker on different phase. Lights are led panel lights.
  37. A

    Domestic 3 phase PV installation question

    Hi - hoping someone can help with the question below, thanks in advance for your time. We're looking at an installation before the FIT goes away, and discussing our needs with a couple of installers. The complication - we're in an old farmhouse with 3 phase supply. One phase is tapped off...
  38. Spaniel

    Commercial 3 phase motor control conundrum.

    Hello, a mechanic friend asked me to check his hydraulic vehicle lift controls as it had failed. When I arrived the lift started working again (of course) but with some contactor chattering upon initial start for approx 5 seconds. He was happy it was working again and wanted to get home, I had...
  39. V

    rcd on a 2 phase system

    hi on an installation i am about to work on it is a 2 phase system, L1 phase has been split between 2 cutout fuses so L1, L1, L2, N & TT earth if a 4 pole time delay rcd is used as the incomer will the rcd work correctly under fault condition, and also will the test button work as normal...
  40. D

    Earthing for 3 phase boards

    Hi just after opinions on this one got three 3 phase supplies all 25mm 4 core swa, armour not been used for earth would you run a seperate 16mm earth for each supply or just loop all the earths from 1 16mm all the supplies are right next to each other
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