NVR Switch

My lathe came with an integral fwd/rev/nvr. I sold it when I upgraded to 3 phase and inverter, but I could scan the wiring diagram if that would help

After looking at the pictures in your album I am not convinced that it is an NVR switch. Start the lathe in the forward direction. Switch the power supply off to the lathe. Did the switch return to the centre off position ? Restore the power to the lathe. Does the motor start as soon as the power was restored ? These tests will show if it is an NVR switch.

Les.

Hi Lynne, I suspect it could be a customized range Kraus & Naimer rather than a stock type. The fault could be a loose connection in the reverse line or a dirty or arced contact in the switch.

Regards Nick.

Lynne

A quick Google turns up the official 2021 Krause & Naimer short form data on the cam switch range at **LINK** https://www.krausnaimer.com/fileadmin/user_upload/Kraus_u_Naimer/Pdfcat/KN120GB.pdf .

From your pictures the switch you have seems to be a standard blue-line cam switch. These things can be built up in myriads of configurations by combining switch blocks, actuating units, control levers and position indication plates. Just a matter of flogging through the various codes for each part to get the device you want. (Headache pills and a wet towel round your head probably essential if starting from scratch.)

Looking at page 6 it appears that the code for a no volt release actuator is CG8X which mates with an S0 size switch. I see no reason why the actuator can't be ordered as a separate unit and replaced. Having changed switch stacks on a similar unit, albeit without no volt release, on my Bridgeport I can confirm that they come off and go back quite easily. However its unwise to remove the connections as figuring out what goes where can be a problem. I had no choice as mine had been bodged round burnt out contacts!

If you decide to order a complete unit it seems like you have a double throw switch with 60° switching angle.

Page 23 shows specific motor reversing switches. Alternatively it could have been built up from switch sets as shown on page 11 where there is a choice of plain centre off or electrically isolated contacts.

Hopefully the codes on the switch bodies are still visible so ordering a new complete unit shouldn't be too hard.

But I'd just change the actuator which ought to be part CG8X. Assuming you have an S0 size switch, easily sorted by measuring as its a bit under 2" square.

Really this is something that the UK agents should be almost instantly aware of. But I didn't find them technically knowledgable in the past. Problem is that, so far as I can see, UK stockists tend to hold build up units in the common varieties rather than getting involved in build to order.

Assuming a 3 phase motor I think part code CG8XA401 be yours. Have to take it apart to figure out the panel mounting system. Probably 4 hole without the escutcheon plate, yours doesn't look to be standard K&N.

Hope this helps.

Clive

Edited By Clive Foster on 06/11/2021 13:09:44

Hi, Bee.M There is a Poundland in Witney, so next time I am in the town, I will pay them a visit and see if I can find the air duster. Thanks for the offer Duncan. I have marked the wires with their location numbers, and have pictures so I don't feel I need the wiring diagram. It's definitely an NVR switch Les. It does all the things you list and does'nt run when power is restored. I suspect that you are correct Nick, and this is a customized unit for Myford. Clive, the pt. no. CA10X A401 ties it down to being part of the CA range, not CG. I think the X denotes latching, and A401 implies a 3 pole motor reversing switch. Building one up from scratch is a bit to challeging for me, but I have e mailed a company up north who stock Kraus, to see if they can help. Thanks though Clive for you input, and going to such lengths to help, and everyone who have posted comment Regards Lynne

Lynne

Another Google turns up the catlogue covering the CA range **LINK**

https://www.krausnaimer.com/fileadmin/user_upload/Kraus_u_Naimer/Pdfcat/KN100GB.pdf

Darned if I can tell the difference as, at a quick glance, the catalogue looks fundamenatlly the same as the one previously linked to.

Agreed X is no volt release version, A401 is the three phase reversing switch set so CA10X A401 makes sense.

But what the difference between CA range and CG range is I know not. It really shouldn't be hard for a company familiar with the range to sort out what you need.

Building up a code from scratch hurts!

Clive

Lynne

Another Google turns up the catalogue covering the CA range **LINK**

https://www.krausnaimer.com/fileadmin/user_upload/Kraus_u_Naimer/Pdfcat/KN100GB.pdf

Darned if I can tell the difference as, at a quick glance, the catalogue looks fundamenatlly the same as the one previously linked to.

Agreed X is no volt release version, A401 is the three phase reversing switch set so CA10X A401 makes sense.

But what the difference between CA range and CG range is I know not. It really shouldn't be hard for a company familiar with the range to sort out what you need.

Building up a code from scratch hurts!

Clive

Edited By Clive Foster on 08/11/2021 13:40:16