vfd and spindle power connection, need best practice advices.

[kalakuta]

Message in a bottle from an beginner DIY CNC router adventurer, please help...

After spending quite some time fiddling around trying to understand the basics of VFD + spindle setup I am left with even more questions than when I started. Sorry if this has been answered a million times, to be honest I am a bit lost since there are sometimes contradictory information's floating around, or answers far beyond my limited knowledge.



My setup:
> Spindle 2.2kW 400Hz , 220V 8A , 8000-24000rpm (Vevor jst-jgd-80C)
> VFD 3kW 220V (single or 3 phase) 14A max, output frequency up to 1kHz (Vevor H100-3S2-1B)
> Power input at 50hz 230V (EU),



Questions about current and powering :

> Is it ok to add an open contact switch (on/off) on the VFD power source ?

> With a VFD at 14A and spindle at 8A is the VFD current limited by the spindle cap., then would it be enough to have a 1 phase input + neutral + ground rated 10A ?

> If not, given my specifications would it be best to have a 3 phase input at 10A or 1 phase + neutral at 16A ?



Questions about grounding :

> from VFD to spindle I have a 4 wire shielded cable (3p + PE). Is it ok to group the shield wire + spindle ground + input 220V earth wire all together on the VFD PE pin ?

> Is it ok if my ground is common to other appliances (e.g. stepper drivers) ? Would they not anyway be connected at the main switchboard if I pull a dedicated cable?


Thanks!

[mactec54]

Message in a bottle from an beginner DIY CNC router adventurer, please help...

After spending quite some time fiddling around trying to understand the basics of VFD + spindle setup I am left with even more questions than when I started. Sorry if this has been answered a million times, to be honest I am a bit lost since there are sometimes contradictory information's floating around, or answers far beyond my limited knowledge.



My setup:
> Spindle 2.2kW 400Hz , 220V 8A , 8000-24000rpm (Vevor jst-jgd-80C)
> VFD 3kW 220V (single or 3 phase) 14A max, output frequency up to 1kHz (Vevor H100-3S2-1B)
> Power input at 50hz 230V (EU),



Questions about current and powering :

> Is it ok to add an open contact switch (on/off) on the VFD power source ?

> With a VFD at 14A and spindle at 8A is the VFD current limited by the spindle cap., then would it be enough to have a 1 phase input + neutral + ground rated 10A ?

> If not, given my specifications would it be best to have a 3 phase input at 10A or 1 phase + neutral at 16A ?



Questions about grounding :

> from VFD to spindle I have a 4 wire shielded cable (3p + PE). Is it ok to group the shield wire + spindle ground + input 220V earth wire all together on the VFD PE pin ?

> Is it ok if my ground is common to other appliances (e.g. stepper drivers) ? Would they not anyway be connected at the main switchboard if I pull a dedicated cable?


Thanks!

The Power requirement for single phase is around 20A, the recommended is 25A to 30A circuit for a 2.2Kw spindle and machine which needs to run all on the same circuit, the spindle will be around 8.5A to 9A x 1.73= rounded 16A plus the code requirement =20A= circuit wiring just for the VFD Drive

If you have 3Ph then you should use it the circuit would still have to be rated at 18A, just for the VFD Drive

No, the shield should never be connected to a Ground wire, the shield can be clamped a small distance away from the spindle to a metal part which is Grounded Ideal you should use the correct plugs for shielding

You need a Ground Bus in your cabinet this is where all your Grounds need to connect.

Shields clamp 360° to the Ground Plane, which is anywhere the cable ends, both ends of the shielded cable need to be clamped or terminated with EMI fittings