Hammer bandsaw how do I run this on monophase

[eaglesalz]

Hello, I have a Hammer n4400 bandsaw 380v 3phase and want to run it on 230v singlephase. Bought a VFD but it is a minefield to me with the programming etc. I have attached some photos of the motor on the bandsaw. I would appreciate your help. Thanks

 

[ChaiLatte]

The motor is suitable for 230v 3-phase operation. Rotate your middle photo 180 degrees so it matches the RH photo and then change the connections to the LH part of the diagram on the RH photo (delta or triangle i.e. not Y).

What do the existing controls on the machine look like? Does it have an E-stop button? Do you want it to run at a single, fixed speed?

With a VFD, all control inputs go into the VFD: it is inadvisable to have anything but an unbroken length of wire from the VFD output to the motor input.

There is a manual here, which suggests it has a DC brake (https://ostiatools.co.uk/wp-content/uploads/2022/02/Hammer-N4400-Bandsaw.pdf). That wil not play well well with a VFD. If you need braking ability, buy a VFD with that ability (which, depending on how much brake force you require, may also necessitate purchase of an external braking resistor).

 

[Fitzroy]

At a high level:
- rewire the motor from star to delta (assuming your VFD is 240v in 240v out)
- wire the motor directly to the VFD omitting any switches
- check the parameters on the VFD
- power it up and use start/run button on the VFD to run the motor

Rewiring the motor involves following the diagram on the cover. Under the nuts on the lower terminals you have three brass bars that are connecting the three terminals together. To rewire to delta, you remove the nuts and the metal bars, and then connect the lower and upper terminals together.

Wiring the VFD direct to the motor is essential, you cannot use the existing switch. If you break the connection between motor and VFD whilst in operation bad things will happen (no idea what but that's what my manual implies), think ghostbusters and not crossing the streams.

Checking the parameters on the VFD. If you have a eBay cheapie (like most of us have) the instructions are likely poorly written but there are lots of videos online showing how to navigate the settings, most of the ebay VFDs have very similar settings and menu structure. If you've purchased a higher quality UK based VFD then the manufacturer will be able to give you all the support you need on the phone. Of the four VFDs I have from ebay they all came ready to roll except for the max frequency being either 60Hz (not an issue) or on one of them it was 100Hz (not great).

When I power on the motor for the first time I do not have the machine belt on the unit, and tend to press run and the stop as soon as the motor starts up.

Fitz

 

[ChaiLatte]

- power it up and use start/run button on the VFD to run the motor

I am not sure it is clear from above that this is for test purposes only. It is not a good long term, sustainable solution to operating the VFD.

The membrane keypad/controls of a VFD are not very robust, often not manufactured for everyday operation (if the keypad is removable, to enable remote operation via a cable, this does not apply). If the keypad wears out, the VFD is effectively scrap. The VFD itself is unlikely to have the correct IP rating for a dusty environment.

 

[Fitzroy]

I am not sure it is clear from above that this is for test purposes only. It is not a good long term, sustainable solution to operating the VFD.

The membrane keypad/controls of a VFD are not very robust, often not manufactured for everyday operation (if the keypad is removable, to enable remote operation via a cable, this does not apply). If the keypad wears out, the VFD is effectively scrap. The VFD itself is unlikely to have the correct IP rating for a dusty environment.

I use the start/run on the control pad for my morticer likely not a great solution for a trade environment but occasional hobby use I think it's ok. Totally agree on the need for a housing/container of some sort for dust. I repurpose plastic click top containers for VFD housings.