Three phase electrical connection query

[Greenbeast]

Ok i have picked up an old hobart bowl mixer that is plated as 3 phase and has a 415V sticker on the back of it.

It currently has a 9H 3P+E Blue plug on it, i don't know if it has ever been used in this configuration or it has been put on prior to being sold at some point in the past (i bought it of someone who never got round to using it).
I've not come across this type of plug before and i'm unsure how to proceed. I bought a 6H 3P+E Red socket because i was mistaken.

Thoughts?

 

[Pheasant Surprise]

What is the current/power rating of the appliance please?

Confirm also it only has the line conductors L1, L2 and L3 and earth connected on the plug?

Plug style is not so important, whether it uses all the phases (and neutral) is the important bit, along with its rating.

 

[Lincsman]

It should be big enough, remember each phase is 230 v, what amps does the mixer require?

 

[Greenbeast]

What is the current/power rating of the appliance please?

Confirm also it only has the line conductors L1, L2 and L3 and earth connected on the plug?

Plug style is not so important, whether it uses all the phases (and neutral) is the important bit, along with its rating.

It should be big enough, remember each phase is 230 v, what amps does the mixer require?

Yeah it's not the size I'm querying, I think it's only 1/2hp, but the fact it has a 240V plug but the machine is 3phase/415V.
I will take the plug off in a minute and see what the wire colouring is

 

[335d]

Blue plug is usually 240v. Has someone rewired the motor to run off a single phase to 3 phase inverter which would have 240V between phases?
Stick up a picture of the motor rating plate, and then one with the terminal cover off to see if it is wired in star or delta

 

[Pheasant Surprise]

Blue plug is usually 240v. Has someone rewired the motor to run off a single phase to 3 phase inverter which would have 240V between phases?
Stick up a picture of the motor rating plate, and then one with the terminal cover off to see if it is wired in star or delta

My guess is that as it’s not been used in anger by the previous owner as @Greenbeast noted, they’ve just wired up a blue 4 pole plug.

But it needs a bit more more investigation as you say.

 

[simon-0116]

Never seen a blue 16a 4 pin in all years as a sparky, 10yrs +. Obliviousy for a diffent set up not your average 1ph or 3ph. @tallguy may know. Not sure how to tag him.

 

[Pheasant Surprise]

@TheTallGuy

 

[milkloss]

The 3ph in the blue plug would be 240v 3ph (vs the standard 415v....as found in red plug). This is usually generated by an inverter that is used to create three phase power from a single phase supply. When this 240 3ph is used the motor would normally be wired in delta configuration as opposed to Y (star) config as with 415v.

Edit to question my own post....... see below. I’m not qualified btw and don’t listen to me

 

[TheTallGuy]

Never seen a blue 16a 4 pin in all years as a sparky, 10yrs +. Obliviousy for a diffent set up not your average 1ph or 3ph. @tallguy may know. Not sure how to tag him.

I've seen a few over the years, but they're rare & wouldn't hook it up to any sort of supply without checking how it was wired up as people have been known to do strange things. As mentioned above a picture of the terminals at the motor end and tge rating plate will give us a clue.

 

[Greenbeast]

I forgot to snap it, but the machine does have a 415V warning sign over this junction box

 

[Greenbeast]

I've seen a few over the years, but they're rare & wouldn't hook it up to any sort of supply without checking how it was wired up as people have been known to do strange things. As mentioned above a picture of the terminals at the motor end and tge rating plate will give us a clue.

Sod it, forgot the plate picture but is is 0.9A, 415V, 3 phase
Will have to dismantle it much more to see the motor winding better

 

[TheTallGuy]

Sod it, forgot the plate picture but is is 0.9A, 415V, 3 phase
Will have to dismantle it much more to see the motor winding better

Okay that's a good start - that means it should be a standard set of windings. When you get to the connections there will probably be 6 wires coming up from the windings - if your supply wires each connect to two winding wires then it's set for delta/240V, if each wire goes to a single winding wire with the other three joined together then it's star wired. There's slight variations that can come into play & hence why a picture would be useful.

 

[milkloss]

The 3ph in the blue plug would be 240v 3ph (vs the standard 415v....as found in red plug). This is usually generated by an inverter that is used to create three phase power from a single phase supply. When this 240 3ph is used the motor would normally be wired in delta configuration as opposed to Y (star) config as with 415v.

Rereading my own drivel here but did I get that last sentence right? Surely delta would be for 415v and star for 240v?

Haven’t played with electrickery for ages and must put my thinking cap on!!!

Don’t listen to me @Greenbeast !!

 

[Pheasant Surprise]

Rereading my own drivel here but did I get that last sentence right? Surely delta would be for 415v and star for 240v?

Haven’t played with electrickery for ages and must put my thinking cap on!!!

Don’t listen to me @Greenbeast !!

Gotta sense of deja vu on this one

Phase to neutral will be 240v
Phase to phase (line to line) will be 415v
Just depends what you’re measuring across

The 3-ph supply is always the same....three individual phases, each 240v with respect to neutral but 120 degrees apart in phase. Hence when you put your meter across the phases, mathematically the voltage is squareroot of 3 x 240v = 415v

So delta connected will be 240V (there is no “neutral” in this wiring scenario - the phases balance out the currents in and out the windings).

Star connected will be 240v from the centre of the star (neutral) to each leg (phase or line as you will) and 415v across the legs.

 

[Greenbeast]

Gotta sense of deja vu on this one

Phase to neutral will be 240v
Phase to phase (line to line) will be 415v
Just depends what you’re measuring across

The 3-ph supply is always the same....three individual phases, each 240v with respect to neutral but 120 degrees apart in phase. Hence when you put your meter across the phases, mathematically the voltage is squareroot of 3 x 240v = 415v

So delta connected will be 240V (there is no “neutral” in this wiring scenario - the phases balance out the currents in and out the windings).

Star connected will be 240v from the centre of the star (neutral) to each leg (phase or line as you will) and 415v across the legs.

So given the current wiring of the plug above, shall i just supply the appropriate phases to it? i.e. should i attempt to find a 9h socket or should i replace the plug with a red 415V 6H plug to match the socket i've bought already? Or do we still need to see the windings?

 

[TheTallGuy]

Oops didn't spot the pictures!

So given the current wiring of the plug above, shall i just supply the appropriate phases to it? i.e. should i attempt to find a 9h socket or should i replace the plug with a red 415V 6H plug to match the socket i've bought already? Or do we still need to see the windings?

You need to check the windings because if it is delta then you would be putting 400V across each winding instead of the nominal 230V that you would have under star connection.

 

[Greenbeast]

I need to give it a deep clean anyway as it's fudging greasy and gummed up, i'm sure the EHO would love that!

 

[Greenbeast]

This is the best view I can get at the moment. What do you need to see?
There a pair of yellow, red and black wires coming from the switch which is fed by the black, black and brown wires that come from the plug through the body

 

[Netherfield]

Pound to a penny that someone has just used(bodged) a blue plug and socket instead of a red one, if the motor was dual voltage it would be stated on the motor plate in my mind.