1

The machine has five wires, three of which are live. I want to wire into a single phase supply using a three prong plug.

It powers a boiler and water pump (for an espresso machine: 220-240V, 50/60Hz, 0.190Mpa/0.65Mpa, 3000W).

The advice I received was to twist the three live wires together and wire them all to the one live prong.

The problem I have is that the the three together is to thick. Is there a way to do this?

Solution: what I found was a connector (not sure what it's called) big enough to take the three wires together with a single wire coming out the other side. Someone else suggested 'wrapping' two of the wires around the third.

Improve this question
7
  • 7
    Unless the machine has a wiring diagram so that you can change it from three phase to single phase this is not going to happen.
    – WarLoki
    Aug 12, 2015 at 9:45
  • 1
    Fascinated by the idea that an espresso machine is set up to run on 3 phase power... maybe you can provide pics/ model number if not an actual wiring diagram.
    – Aloysius Defenestrate
    Aug 12, 2015 at 13:21
  • @AloysiusDefenestrate it's presumably of European origin, given the specs, and 3-phase is more widely distributed there, AIUII. I do wonder if the Wattage is really 3100, not 310, which seems rather low.
    – Ecnerwal
    Aug 12, 2015 at 13:35
  • @Ecnerwal -- I learn something new here every day. And agreed that a 310W boiler would be pretty sad.
    – Aloysius Defenestrate
    Aug 12, 2015 at 13:46
  • @Ecnerwal: Is three phase more common in Europe than the U.S.? I don't think I have seen anything but large European industrial installations with 3 phrase. In the U.S., 3 phase is in most residential neighborhoods and in the largest houses and medium-plus sized businesses.
    – wallyk
    Aug 12, 2015 at 19:50

3 Answers 3

Reset to default
8

You can't just fix this with wiring.

You either need to get 3 phase supplied to your location and wired to the device, or you need a phase converter, such as what these guys sell:

http://www.northamericaphaseconverters.com

A possible alternative might be to use a VFD, such as this one:

http://www.automationdirect.com/adc/Shopping/Catalog/Drives/GS2_%28115_-z-230-z-460-z-_575_VAC_V-z-Hz_Control%29/GS2_Drive_Units_%28115_-z-230-z-460-z-_575_VAC%29/GS2-11P0

In either case, I would seek advice from the device manufacture's tech lines to confirm it's suitable for your application. These devices are generally expected to be connected to a motor, and you have a heater - that is an electrically significant difference.

Also note that I doubt the 3 phase is just powering the boiler. I don't know coffee, really, but I thought high-end espresso machines were pump driven - the pump will be 3 phase too I suspect.

Improve this answer
3
  • 1
    There may also be electronics that run off only one of the legs at 120V.
    – William S.
    Aug 12, 2015 at 17:41
  • Thank you for this information. Pump also, yes. A phase converter would be very expensive for me so I was pleased to find out that combining the three wires is common practice here - I've now down that and it's working.
    – Stephen
    Aug 21, 2015 at 18:11
  • Ok, well I'd say you got "lucky" - again I don't know espresso machines, and perhaps they are generally designed in a way that means they'll work when you rewire them in that way, however as a general rule 3 phase equipment will not work using this approach.
    – RobotAndy
    Aug 24, 2015 at 12:24
5

Lacking a model number to look up, I would try opening the device near the power cord and see if there is a jumper assembly or instructions for converting to other voltages and phase supplies.

Improve this answer
6
  • 1
    This is a poor course of action that would likely result in injury or destruction of the equipment. Do not attempt.
    – William S.
    Aug 12, 2015 at 20:55
  • 3
    I upvote WallyK. Its a good idea. Lots of machines have voltage conversion methods.
    – Trout
    Aug 12, 2015 at 21:32
  • 4
    +1 to wallyk -- this is the land of DIY, and a prudent individual would unplug the machine and use appropriate caution, possibly including the use of insulated screwdrivers. I've owned (and entirely stripped/rebuilt) a one group commercial espresso maker, and I can assure you that stored high voltage electronics is not one of that machine's attributes. Power goes mainly to the boiler, a little to the pump, and a bit to the brain if it does electronic dosing.
    – Aloysius Defenestrate
    Aug 12, 2015 at 23:56
  • 2
    @cathode -- many machines are designed for this -- there will be a marked jumper or switch for the job.
    – ThreePhaseEel
    Aug 13, 2015 at 3:25
  • 1
    @cathode: Since the three phase appears to be for heating elements and not a motor, this is a moot issue.
    – wallyk
    Aug 13, 2015 at 17:03
4

Having recently purchased and rewired from three phase to single phase on a Wega Pegaso coffee machine.
enter image description here
This is what I found and did successfully. Firstly most commercial coffee machines are mono-phase, and can be wired 3 or single phase. The 3 phase has 3 individual lives all acting independently, by joining these together they act as one. One supplies the power the other 2 cancel each other out. You should not risk wiring to a 13amp plug but install a dedicated 20amp supply from your mainboard to a new socket near your machine. I have a 2 group machine, with a 3.7kw boiler, stating 400 volts (three phase). I have had no problems making 4 coffees at a time and all pressure etc are perfect. Hope this helps as it took me nearly a day of searching before I finally was confident to tackle the wiring.

Improve this answer
1
  • Hello, and welcome to Home Improvement. Thanks for the answer; keep 'em coming. And, you should probably take our tour so you'll know how best to contribute here.
    – Daniel Griscom
    Aug 3, 2019 at 12:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.