Power Switch For Huanyang 2.2KW Inverter

So, I’m just starting to set up my first spindle and VFD - the Huanyang variant of English has me a little spooked. I need to source a power on/off switch for the 220 volt VFD. On some devices (like my 220v air cleaner) it is sufficient to have a single pole switch on either hot leg. What are you 220 VFD users using to power the Huanyang on and off?

Not huayang but informative quick read about related needs on a related vgd/spindle combo. Don’t break the power between the vfd and the spindle.

Eaton 30-Amp Double Pole Toggle Light Switch, Ivory in the Light Switches department at Lowes.com

Hey Andy, hey John,

yes, you don’t really want to know what happens when your kilowatts induction motor, from one microsecond to the other, becomes a kilowatts induction generator when spinning at high speed and the current is cut off (and it cannot reach the braking chopper inside the VFD and the braking resistor (see also dynamic breaking)).

Even the Huanyang has this warning in its manual :slight_smile:, only the picture that shows it is strange. The little “x” on page 5 means “don’t do this”.

On my Omron MX2 Manual, there is also the

:warning: Warning to put a switch on the input of the VFD:

Hi, first post on this forum. :slightly_smiling_face:

For safety and Code compliance, you must switch both legs if the VFD is hardwired into the branch circuit. If it’s connected to the branch circuit with a cord and plug, then the plug can serve as the Disconnecting Means when you need to remove power from the VFD and the switch could be a single pole. IMO it’s still a good idea to switch both legs, because some one, some day, is going to assume the power is completely Off when the switch is off position.

The current at 240V is pretty low (10A) and normal 2-pole snap switches are rated higher. Technically, you’re supposed to use Motor Rated switches. Standard snap switches aren’t motor rated and are limited to 2 HP. 2 pole 30A motor rated switches are good for up to 5 HP (more than the 3 HP here), but they cost about 4X as much. If you use standard switches, don’t switch it off when the spindle is running except in emergency.

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There is a suggestion made in the manual page above that all of us should consider.

That is adding a magnetic switch on the mains power side of your VFD or router. If the power goes out unexpectedly, it can come back on just as unexpectedly, and that could be bad. Better to have it stay off if power is lost.

In my shop I have replaced the power switches on many of my 120v stationary power tools with magnetic switches. My tablesaw is 240v so it already had one, but on the planer, jointer, drill presses, router table, and bandsaws I am in the process of changing the switches over or installing a switch in line before the tool for those that I cannot replace the switch directly.


Thank you, everyone.

I used these for power to the VFD and created my own enclosure. It is a 2-pole and rated for almost double the VFD’s amp draw and they work great. I bought the same thing in single pole as well for the water pump for the spindle
Amazon.com: Baomain Red Light DPST ON/Off Snap in Boat Rocker Switch 4 Pin 16A/250V UL TUV List 1 Pack : Sports & Outdoors

Interesting. So if power is lost to the VFD while the spindle is running, and it then comes back, the spindle would resume running without having to press the Run button? That’s what they seem to be saying. If that’s the case, then yes a magnetic switch is probably a good idea.

Hey Barry,

yes, it “may”, but it depends on how the VFD is set.

– Source: Omron MX2 User’s Manual, Page XIII

The behaviour of the VFD in case of a short power failure can be tweaked this way:

– Source: Omron MX2 User’s Manual, Page 121

– Source: Omron MX2 User’s Manual, Page 122

In my spindle manual, it says:

5.1 Electrical Risks

Ensure protection against overload or short circuit!

In the event of an overload - for example due to the motor shaft being jammed - or due to a short circuit, it must be ensured that the motor spindle is immediately disconnected from the voltage if the current exceeds the rated current of the motor spindle. Even if a phase fails, the motor spindle must be immediately disconnected from the voltage. This can be achieved with suitable motor protection switches or the appropriate parameterization of the frequency converter.(1) It is essential to ensure that the motor cannot start up automatically after the protective device has been triggered! Non-observance can result in an impermissibly high temperature rise in the motor spindle, which can lead to damage to the motor spindle and machine and even a fire hazard.

– Source: Mechatron HFS Series High-Frequency Spindle Operating Manual

  1. This is the reason why in a good VFD, you can adjust these settings.

But the spindle manual also says:

5.2 Risks from rotating parts and flying debris

Use machine encapsulation!

The high speed of tools up to 24,000 rpm poses a risk of injury from flying chips or the tool bursting. Fragments reach high flight speeds and can sometimes cause serious injuries. A separating protective device (machine encapsulation) must therefore be used that protects against flying chips and debris and also has a safety switch that disconnects the frequency converter or the motor spindle from the power supply on all poles as long as the encapsulation is not closed.

– Source: Mechatron HFS Series High-Frequency Spindle Operating Manual

That is why ISO 13849 Safety relays like the Omron G9SE (datasheet) have an input for a sensor switch on the door of the enclosure of a CNC machine, which signals him someone opened the door, which allows, if VFD is configured appropriately, to decelerate spindle immediately.

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I used this 220v 30a switch between my VFD and the wall power.

Hey Barry,

I second Bob @Bob_D with his suggestion that it is always a good idea on tools that can harm humans (and cats)

If you’re using a router it definitely will start back up unless you have taken some step to disable it. But can you do that fast enough?