New to the Blanchard club

[Spruewell]

Found out she’s wired for 480V. I only have 220 in my shop. Looks like I’ll have to go in and re-wire each motor as well as the rectifier for the mag chuck. I’ve been going through the manual I have for it, and haven’t been able to find information on the electrical panel that would tell me if there is anything in there that needs to be changed for 220. Anybody out there have any experience with this? It all appears to be original equipment in there with massive contactors, cloth insulated wires and everything.

 

[Mr. M]

Wouldn't it be easier to find a transformer to step it up to 480v?

 

[Mud]

Wouldn't it be easier to find a transformer to step it up to 480v?

+1, what is the rated amp draw?

 

[Garwood]

Mine looks just like yours. Mine has a wiring diagram glued inside the electrical cabinet door.

From my experience switching other stuff over you'll have a control transformer that you retap along with every motor. In addition, the big problem, is you have to change out the heaters in every contactor for the now higher current. You also have to verify every contactor will handle double the current. Sometimes they won't.

I'd put it on a transformer. You probably won't be able to find heaters for those ancient contactors. So you'll have to replace them all. Plus the fabric motor leads are likely to crumble when you rework them.

45kva is a common size 240-480 transformer. I've bought several for $200ish. Hook it up backwards and it should feed your blanchard.

 

[Spruewell]

That is sounding like a better way to go. Should save me hours of re-wiring and troubleshooting. I’ll start hunting one down.

Next adventure is going to be pulling the mag chuck so I can get the way covers off and clean the ways. The big core holes in the table were completely plugged. So bad I didn’t even know they were there until I started digging.

 

[Doug]

Mine looks just like yours. Mine has a wiring diagram glued inside the electrical cabinet door.

From my experience switching other stuff over you'll have a control transformer that you retap along with every motor. In addition, the big problem, is you have to change out the heaters in every contactor for the now higher current. You also have to verify every contactor will handle double the current. Sometimes they won't.

I'd put it on a transformer. You probably won't be able to find heaters for those ancient contactors. So you'll have to replace them all. Plus the fabric motor leads are likely to crumble when you rework them.

45kva is a common size 240-480 transformer. I've bought several for $200ish. Hook it up backwards and it should feed your blanchard.

Yes....as I have said a few times before "Feed it what it wants"
You covered every point I did as well.

 

[Mr. M]

I got a surface grinder that runs on 460v. It is pretty basic but quickly became apparent that a transformer was the better/easier/cheaper option.

 

[Carbidebob]

Have you priced a transformer big enough for this machine's requirements.
Let alone the shipping weight and size plus it's constant power loss. (It will make a nice spot to keep the coffee cup warm).
Just say no and rewire.
Control transformer and then the wires inside each 3 phase motors. So Spindle, rapid up/down, and chuck rotation motors.
The magnet control will likely also have such high/low wires.
If so old that you can not find heaters maybe it is time to change the contactors.
But for mine one built in WWII I can still find heaters.
Have to admit the wires in it getting a bit old so a swap to new contactor block should mean new wires.
If this confusing the help of a machine tool electrician may be of help.
This is not the local electrical guy who wires houses and such for a living.
Make the journey and learn a bit. (I remember my first)

 

[Spruewell]

I was actually envisioning wiring in the transformer after the main switch. That way it only is on when the machine is on. I have a transformer from an old machine that I had to mothball that I think might be able to do the job.

 

[mach ramsey mn]

I would do the calculations to figure what you need from the full load amps on the grinder at 80%. For example if the grinder takes 30 amps (37.5@ 80%) at 480v works out to be 31Kva. Just to throw a 45 Kva transformer on there if you only need 30Kva is kind of a waste. Besides a 45Kva transformer will pull 125 amps @ 208 volts(55 amps @480v). The inrush will be considerably higher. The contacts on the grinder disconnect aren’t likely to be that high. Just my thoughts.

 

[Garwood]

I would do the calculations to figure what you need from the full load amps on the grinder at 80%. For example if the grinder takes 30 amps (37.5@ 80%) at 480v works out to be 31Kva. Just to throw a 45 Kva transformer on there if you only need 30Kva is kind of a waste. Besides a 45Kva transformer will pull 125 amps @ 208 volts(55 amps @480v). The inrush will be considerably higher. The contacts on the grinder disconnect aren’t likely to be that high. Just my thoughts.

They are derated running in reverse. Hence why I suggest 45kva

 

[mach ramsey mn]

They are derated running in reverse. Hence why I suggest 45kva

As I indicated , 80% of name plate. Or for the calculation increase the full load amps 20%

 

[Mud]

And be very careful about grounding when backfeeding, look at the diagram on the transformer carefully and maybe consult someone who has done it. Transformers are built very differently.

 

[mach ramsey mn]

A wye-wye transformer would be preferred. Typically the transformers you will find will be Wye configuration on the low side and Delta on the high side. If this is what you end up with you need to wire it as a “grounded Delta” configuration. This is done so if something in the machine shorts to ground it cannot backfeed that grounded power back through your whole electrical system. Think of it like this, that Delta power coming out of the transformer if not bonded (grounded) properly is like a whole isolated power system from all other power in your shop.
On a Wye-Wye transformer you bond the center connection ( usually X4 and L4 connections) and all is good,

 

[Doug]

Check out HGR for a xformer.

 

[MwTech Inc]

Last two transformers (30 kva) I bought to take 480 down to 208 were both less than $250
Square d and Siemens

 

[Spruewell]

This is the Transformer I have. It was hooked up to an old Nakamura TMC-2.



I think I can use this, but if anyone knows better, I'm listening

 

[Spruewell]

Pulled the chuck on this thing and found the surface of the ways to be in need of some help:






Looks like something got in there and tore it up. I checked the pinion and ring gear, they both look fine. Whatever it was, I haven't been able to find it yet.

 

[Garwood]

Probably just ran low on oil. I'd stone off the high spots and run an indicator on the table while spinning. If it's smooth I'd run it. "Lubrication pockets".

 

[Carbidebob]

Looks normal for a Blanchard.
Lightly stone and clean the sump well.
In these grooves are particles waiting to let loose.
I like to use schocthbrite to remove such.
.....But then super cleaning the sump and chuck bottom is even more important.