4 or 5 pin plugs for 3 phase supply from inverter?

[pgrbff]

I have recently bought a 3 phase bandsaw for hobby use and acquired a single phase to 3 phase inverter to power it.
When I looked at buying cable and plugs/sockets for the supply I didn't know if I should choose 3P + earth or 3P N + earth plugs and sockets.
What is the difference and which should I buy?

 

[Mike Johnson]

How many pins on the bandsaw socket, this will indicate what you need to plug in that end and how many cores the cable should have.

 

[pgrbff]

Its a 60 year old dual voltage. 3 plus earth is all the bandsaw needs. I'm just curious as to why the neutral and if the 3P N and earth is just the lastest version?

 

[James]

You need a 3 pin socket because your supply is single phase.

Then you will need to rewire the saw to include the inverter and remove the original 400v contactors.

Also change the motor configuration from star to delta, assuming it is a dual voltage motor (400 star, 220 delta)

 

[pgrbff]

The plate says 260V 5A in delta. I assume 1.5mm is sufficient? Any reason to use 2.5mm?

 

[Mike Johnson]

5A in delta, sure there is not a 1 missing off the front of that, it's a very low power for a Bandsaw.

 

[James]

That’s 5A per phase. So 1.5 from inverter to motor is ok but inverter needs to have 15 to 20A supply. What spec is the inverter?

 

[pgrbff]

5A in delta, sure there is not a 1 missing off the front of that, it's a very low power for a

 

[pgrbff]

That’s 5A per phase. So 1.5 from inverter to motor is ok but inverter needs to have 15 to 20A supply. What spec is the inverter?

Input Current: 18.1A/13.5A
Input Voltage: 200V-240V Single or Three Phase ±10% at 50-60Hz ±5%

 

[James]

Do you have anyone experienced in 3 phase control and/or any electrician to wire this up to your house?

there are plenty of places where this could go wrong if not thought out and designed correctly.

some might be an inconvenience, others could be a danger.

 

[ipf]

I can smell a bit of 'boom boom' in the air.?

 

[pc1966]

Unless absolutely necessary get a 5-pin socket and make sure the neutral is connected.

If you have a delta-style load (only using L1-L3, like your motor above) you can ignore the N, whereas if you don't have the N connection for any star-style load in the future (L1-L3 & N) it is going to end very badly for something, or someone!

 

[pgrbff]

I can smell a bit of 'boom boom' in the air.?

Uncalled for.

 

[pgrbff]

I have no problems wiring the inverter but I have never used 3 phase.
This is the junction box on the saw and how I believe it should be re-wired. But I am confused about the neutral?
I can buy 4 pin or 5 pin ind plugs/sockets and I just really wanted to know which I should use and why.

 

[James]

A 3 phase motor has no neutral connection
As said before, the socket on your wall needs to be 3 pin as it is single phase.
The inverter to motor cables should be part of the machine wiring and not require a plug and socket.

 

[ipf]

I have no problems wiring the inverter but I have never used 3 phase.
This is the junction box on the saw and how I believe it should be re-wired. But I am confused about the neutral?
I can buy 4 pin or 5 pin ind plugs/sockets and I just really wanted to know which I should use and why.

Totally called for, it seems.
If you don't understand it, DO NOT mess with it.

If you're determined to, get information first hand...... and face to face from someone qualified to offer it.

 

[Steviec1]

Totally called for, it seems.
If you don't understand it, DO NOT mess with it.

If you're determined to, get information first hand...... and face to face from someone qualified to offer it.

Your motor is wired star, you will need to wire it in Delta. 3 pin supply plug.
In case you were thinking of it, it is not good practice to wire from an inverter to a motor via plug and socket.
It will be better to get a 4 pole 20A isolator with an auxiliary and wire the 4th pole and auxiliary back to the inverter enable signal.

 

[Mike Johnson]

And wired through a NVR switch.

 

[pgrbff]

Totally called for, it seems.
If you don't understand it, DO NOT mess with it.

If you're determined to, get information first hand...... and face to face from someone qualified to offer it.

So you have someting against me learning? the only error I seemed to have made so far is not appreciating that I need screened cable between the motor and inverter. Luckily, by seeking help, albeit socially distanced, i discovered before ordering.

 

[James]

So you have someting against me learning? the only error I seemed to have made so far is not appreciating that I need screened cable between the motor and inverter. Luckily, by seeking help, albeit socially distanced, i discovered before ordering.

Learning is good and should be encouraged,
However, it is difficult for us to understand the entire setup you are planning with the limited information provided.

Perhaps you could post a drawing of how you intend to set this system up.
Just a simple block diagram, we still dot know where in the system this 4 or 5 pin plug is intended to be fitted.

Converting a 3phase machine to single phase is not as simple as putting an inverter inline on the supply cable and changing the motor configuration.

There are serveral other things to consider.
Some have been mentioned but not replied to.

You have mentioned that it must be screened cable from inverter to motor, this may or may not be the case.
It depends on make and model of inverter
Distance of cable run between inverter and motor
Proximity to other cables and equipment

As mentioned before, consideration needs to be made for replacing the original contactors and control gear that is likely to be the wrong voltage and not suitable for being powered by an inverter

Many inverters are Simpley not suitable for running off a domestic socket because of emc filtering, dc leakage, start up surge etc.