What did I get myself into??

Dgleavitt

Registered
Registered
Joined
Oct 9, 2017
Messages
37
I picked up this “Surface Grinder” for 100 bucks. Supposed to be wired for 110 but get there and it is 220/440 3 phase. I got it anyway and hoping I can wire it for 220 and run a Teco VFD.

BUT...what is it??? It is a Royal Oak
D-S Grinder with a turntable head and dual wheel spindle. Can anyone tell me anything about it?

41F8AF7E-7AE7-4F6D-8D3E-30A4FA5FF926.jpeg


C1A6B884-42A0-4E9A-85F8-9C9E60691883.jpeg
 
Also forgot to mention that the hand wheels are also the “dials”. Scribed in thousandths.
 
Royal Oak is well known for form tool grinding equipment, but this one looks more like a simple tool & cutter grinder.
 
Well that’s too bad, I was under the impression that tool and cutter grinders had a movable(angle) table, where this one is fixed. For 100 bucks I can’t complain too much, but I have to buy a teco fm50 which is another 115+shipping.
The grinder(220/440) is currently wired for 440v 3 phase. There is no wire diagram or numbers on the leads. Anyone happen to have a Lamb Electric 1/3 HP grinder head and know how to wire it to 220?
 
How many wires are there? There are basically two different wiring diagrams for 3 phase motors, star and delta connections.
 
6 wires. The guy said it is wired for 440 now. It’s has three separate leads and then three wires joined together
 
If it is star wound, that is the connection for low volts (220)
line 1 1&7 together
line 2 2&8 together
line 3 3&9 together
4,5,&6 together
for 440 volts,
line 1 1
line 2 2
line 3 3
Together; 4&7, 5&8, 6&9
Take the tape off the connections and see if the numbers correspond with above; the connections for delta windings, the numbers are entirely different, but the high volts connection would be correct for your motor if it is indeed connected for high volts. For delta connection, low volts would be
line 1- 1,6,& 7 together
line 2- 2,4, & 8 together
line 3- 3,5,&9 together

The only way to confirm whether a star or delta connection is to separate all the wires and read out ohms between the windings, but I doubt that you will need to do that, likely it is a delta connected motor, if in fact the guy knew for sure that it was connected for high volts.
 
The info above came from a publication called "Engineering Pocket Handbook" it has lots of good info regarding electrical issues in a practical format, I have had my copy for about 48 years, and wouldn't be without it.
 
No numbers only faint colors. The three separate wire(1,2,3 I guess) are white(ish) brown and black and the other three(connected together) are also white, brown and black.
 
Back
Top