UK 3 Phase Motor Star/ Delta phase conversion

[xpistos]

Hi Guys,

We have a CNC router which uses single phase for the spindle, stepper motors and control box. This is all wired in and working correctly.

However, the CNC also features a vacuum bed, powered by a seperate 3 phase motor.

We have no 3 phase in our shop, the motor is labeled as 4kW, star or delta wiring options and 480v / 230v at 16 amps and 30 amps respectively.

I believe our only option is 3 phase conversion, I believe the two main options are a rotary phase converter or a inveter (VFD) which is most suitable? Or is there another option I am not aware of that would be better suited?

There shouldn't be any variation on load or need to control load speed, the vacuum bed is turned on and runs at full power.

Thanks in advance, excited to get the CNC up and running and start producing our own in-house rather that subbing out all CNC work.

UK based if it makes any difference!

 

[James]

I would use a single phase inverter
likely to be the cheapest option and the most reliable.

 

[xpistos]

I would use a single phase inverter
likely to be the cheapest option and the most reliable.

Just to clarify, single phase inveter only output 230V 3 phase? So that's delta connection on the motor and we're away?

Can you get inverters rated at 30amp?

 

[James]

Yes, delta connection.
will find an inverter for you.

 

[James]

Invertek Optidrive E3 IP66 Indoor/Outdoor 4kW 230V 1ph to 3ph AC Inverter, DBr, C1 EMC - AC Inverter Drives (230V)

Part No: ODE-3-320153-1F4A, Brand: Invertek, Model: Optidrive E3 IP66 Indoor/Outdoor 4kW 230V 1ph to 3ph AC Inverter, DBr, C1 EMC

inverterdrive.com

 

[xpistos]

Invertek Optidrive E3 IP66 Indoor/Outdoor 4kW 230V 1ph to 3ph AC Inverter, DBr, C1 EMC - AC Inverter Drives (230V)

Part No: ODE-3-320153-1F4A, Brand: Invertek, Model: Optidrive E3 IP66 Indoor/Outdoor 4kW 230V 1ph to 3ph AC Inverter, DBr, C1 EMC

inverterdrive.com

Thank-you for your help, I will upload a picture tomorrow of the plate on the motor just to ensure all loads, amps etc are correct.

Going from memory atm, but I am aware that 240v, 30amps and 4kW doesn't quite add up

 

[xpistos]

Digital phase converter

Would this be suitable to power the attached motor?

 

[James]

Possibly,
they have been around for years and were previously known as static convertors. (instead of rotary convertors)
they are far from perfect in there operation and are also only suitable to run a single motor.

note: until the motor is turning, there will be no power available on one of the phases so careful consideration has to be applied to the control circuit or contactor to ensure it only requires the 2 phases that are permanently supplied.

 

[freddo]

The control circuit (if any) should be suitably connected to the IO terminals of the inverter to start/stop the motor, a relay may need to be used if the inverter is expecting to be controlled by a dry contact. The motor should be directly connected to the inverter as most inverters will throw up error codes if the motor is switched at the output.

I'm assuming the bed here is just a motor and currently has no controls?

 

[James]

It’s a side Chanel blower brought on currently
DOL via a contactor from an external supply.
I think he is just waiting now for a suitable single phase supply to be installed.

 

[xpistos]

I got this all wired in and working thanks to the help from James, absolutely top man.

Do have a small issue with current imbalance atm, L3 (labeled as output W) on the DPS we get is outputting a might higher current than the other two legs (around 50A) this is causing an overheating issue and the motor to shut off after 15 minutes of operation.

Have tried to wire up W to other phases incase irs a motor winding issue but the high current always follows the W output, pointing towards a supply issue with the DPS.

When under load the current does drop to around 45A but this is still over the rated 30A of the motor and thermal shut down occurs.

Got me stumped again does anyone have any suggestions?

Thanks