VFD for surface grinder

[DavidR8]

I'm exploring my VFD options for my new surface grinder. It has a 1 hp motor.
I have 110V in the location for the grinder so I'm looking at this VFD ass compared to running a new 220v circuit.

L510-101-H1-U - TECO-Westinghouse Motors (Canada) Inc.

www.tecowestinghouse.ca

I have a Teco for my mill and I'm familiar with it's programming.
For this application, I'm thinking that forward and speed control would be the only controls necessary?

 

[mksj]

That Teco will work fine as long as it is a direct connect to the motor and there are no other motorized drives/transformer, etc. in the connection pathway. You should be able to get the Teco for around $150 US, not sure to BC Canada. You do not want to use a static converter for a surface grinder drive motor, others have reported surface issue problems when using them.

 

[DavidR8]

Thanks @mksj, appreciate you weighing in!
There's a coolant pump but I don't plan on using it.
I had read about the static converter issues also.

 

[machPete99]

Maybe I have been living under a rock but I have never heard of a need for variable speed on surface grinders.
If that is the case then you could probably save some money by using one of those "static" phase converter boxes.

 

[DavidR8]

The only reason I saw for the variable speed is that the there's a variant of my grinder with variable speed.

 

[macardoso]

You can find VFDs that have a special voltage doubler circuit to run 200V class motors off of 100-120VAC 1P. These are available to about 2HP if I remember correctly. The better option is to supply 200-240VAC to the drive to begin with. The VFD should do fine with the motor, although if the motor has a low class of insulation on the windings, the higher dv/dt spikes from the VFD will tend to wear the windings down faster than one rated for use with a VFD (inverter duty)

 

[mksj]

It is not as much using it for variable speed, but to generate 3 phase with full Hp. There are a number of posts where there was noticeable deterioration of surface finish using a static converter on surface grinders. That particular model of VFD has a voltage doubler built in, so runs off of 120VAC and outputs 3 phase 220 VAC. In general, insulation breakdown when using VFD's is less of an issue with motor's rated as dual voltage 220/440 and also not pushing the motor beyond it's name plate specifications. Using a lower carrier frequency in the 2-6 kHz range is also helpful, less of a problem if run at 60Hz but still can be annoying. Issues with older motors running off a VFD, is typically not a problem with infrequent use as a hobbyist. It is possible to get a dv/dt filter between the VFD and motor to decrease the spikes if one if one is concerned. They can be picked up on eBay or other sources for not much, but I wouldn't worry about it in this situation.