Thread: Motor Contactor for Rotary Convertor/5 HP lathe

Getting ready to fire up my Monarch 14C lathe equipped with a 5HP 3 phase motor. As I said the motor is 5HP, 208-230-460 volts, 14.2-12.6-6.3 amps respectively SF 1.15 and RPM 3485 if that matters. I will be running it with 2 phase 220 volt(?) line power going through a 10HP rotary phase converter. The lathe now has the original circa 1942 vintage motor contactor on it which is an ancient looking General Electric unit. See attached pic.

Far as I can see this GE unit is just a contactor and not an overload device. So I was wondering what I should consider using instead? Years ago I studied motor contactors that contained heating elements that provided overload protection but I have pretty much forgotten all that stuff. Not even sure if that technology is even used now. I want protection for current overload at the motor so was wondering what sort of device could provide both a motor contactor and overload protection for the 5 HP motor? Thanks.

Randy

Originally Posted by rhoward

Getting ready to fire up my Monarch 14C lathe equipped with a 5HP 3 phase motor. As I said the motor is 5HP, 208-230-460 volts, 14.2-12.6-6.3 amps respectively SF 1.15 and RPM 3485 if that matters. I will be running it with 2 phase 220 volt(?) line power going through a 10HP rotary phase converter. The lathe now has the original circa 1942 vintage motor contactor on it which is an ancient looking General Electric unit. See attached pic.

Far as I can see this GE unit is just a contactor and not an overload device. So I was wondering what I should consider using instead? Years ago I studied motor contactors that contained heating elements that provided overload protection but I have pretty much forgotten all that stuff. Not even sure if that technology is even used now. I want protection for current overload at the motor so was wondering what sort of device could provide both a motor contactor and overload protection for the 5 HP motor? Thanks.

Randy

Yes motor switches with heaters for protection are still used. I usually find something on Ebay when I needed a replacement as they are much cheaper than the electrical supply houses..

Good luck with your Lathe!

The starter looks fine to me, I see overloads on it. Bob

I agree. It is a typical NEMA size 1 unit. The heaters for the overloads are the two items faarthest to the right and left. The one on the right is marked C1136 and T3. You may to change the heater for the current you will draw, but there is a good chance those will work. Wire it up and make chips.

Bill

Motor needs to be 1750/1800 max rpm, not twice that

If it has the normal 16 speed tag like the Thumbnail, you will find the clutch pulley speed in the upper right hand corner.

See the motor specs (and clutch pulley speed) for the 16" here

Monarch 16 W by John Oder | Photobucket

Originally Posted by rhoward

Getting ready to fire up my Monarch 14C lathe equipped with a 5HP 3 phase motor. As I said the motor is 5HP, 208-230-460 volts, 14.2-12.6-6.3 amps respectively SF 1.15 and RPM 3485 if that matters. I will be running it with 2 phase 220 volt(?) line power going through a 10HP rotary phase converter. The lathe now has the original circa 1942 vintage motor contactor on it which is an ancient looking General Electric unit. See attached pic.


Far as I can see this GE unit is just a contactor and not an overload device. So I was wondering what I should consider using instead? Years ago I studied motor contactors that contained heating elements that provided overload protection but I have pretty much forgotten all that stuff. Not even sure if that technology is even used now. I want protection for current overload at the motor so was wondering what sort of device could provide both a motor contactor and overload protection for the 5 HP motor? Thanks.

Randy

That contactor was made sometime between 1960 and 1964. Pull the coil hold downs off the coil and the center lifts out for contact inspection and replacement. Looks like it has hardly been used.

Tom

Originally Posted by johnoder

Motor needs to be 1750/1800 max rpm, not twice that

If it has the normal 16 speed tag like the Thumbnail, you will find the clutch pulley speed in the upper right hand corner.

See the motor specs (and clutch pulley speed) for the 16" here

Monarch 16 W by John Oder | Photobucket

Yes, I am replacing the original 1800 RPM motor with the higher speed motor to get max spindle speed a little higher. I have reduced the drive pulley size so max speed will be around 1,000 RPM now. The speed label will no longer be accurate but I can figure it out with a hand tach.

Randy

Originally Posted by johnoder

Motor needs to be 1750/1800 max rpm, not twice that

If it has the normal 16 speed tag like the Thumbnail, you will find the clutch pulley speed in the upper right hand corner.

See the motor specs (and clutch pulley speed) for the 16" here

Monarch 16 W by John Oder | Photobucket

PS - Thanks for the pics!

Randy

Originally Posted by rhoward

Getting ready to fire up my Monarch 14C lathe equipped with a 5HP 3 phase motor. As I said the motor is 5HP, 208-230-460 volts, 14.2-12.6-6.3 amps respectively SF 1.15 and RPM 3485 if that matters. I will be running it with 2 phase 220 volt(?) line power going through a 10HP rotary phase converter. The lathe now has the original circa 1942 vintage motor contactor on it which is an ancient looking General Electric unit. See attached pic.

Far as I can see this GE unit is just a contactor and not an overload device. So I was wondering what I should consider using instead? Years ago I studied motor contactors that contained heating elements that provided overload protection but I have pretty much forgotten all that stuff. Not even sure if that technology is even used now. I want protection for current overload at the motor so was wondering what sort of device could provide both a motor contactor and overload protection for the 5 HP motor? Thanks.

Randy

Can anyone provide a schematic for the pic that I posted of the GE contactor? All the wires were cut and I am not sure how to wire the thing. Thanks.

Randy

Better photos folks can discuss if they like. This is one number off from yours

Originally Posted by rhoward

Can anyone provide a schematic for the pic that I posted of the GE contactor? All the wires were cut and I am not sure how to wire the thing. Thanks.

Randy

Originally Posted by johnoder

Better photos folks can discuss if they like. This is one number off from yours

The black wires in pic 1 are for connections to two of your power line phases. The unconnected screws
on the bottom are connected to your machine motor/electrical.

T1----OL(left side one)----Machine power
T2----Contactor(raised screw in the middle of pic 2)----Machine power
T3----OL(right side one)----Machine power

The red wires are from the switch contacts. The two blocks are NC (Normally Closed)
switches wired in series to the control circuit for the contactor coil. The pic 3
red wire is using the 4th contact point as a Aux Contact for the machine start/stop circuit.
Notice the raised screw on contactor (far left pic 2), this is the Aux Contact.

230V----Stop switch(NC)----Aux Contact(each side connected across start switch)----Coil----OL(right side)----OL(left side)----230V

OL = denotes the two blocks on the sides.

This should get you sorted out.



SAF Ω

Originally Posted by SAF

This should get you sorted out.



SAF Ω

Very cool. Thank you SAF

Randy

Thanks for this schematic. I couldn't find the instruction sheet for this. Also, I'm new to this forum.

I have a few instruction sheets for other GE industrial controls that I can share. What might be the best place to post copies. I also have some electro/mechanical time delay relays and such. If they can be useful, glad to do it.