Chester lathe DB10GVS

[michael27Participant @michael27]

Hi

i I have the above lathe which has suddenly stop working.I have change both fuses, and the green/ red on/off button still not working unless you hold the green button in
my guess that the printed circuit board as blown?

As anybody come a cross this before or can suggest where to look next.

Thanks for any help

[Bo’sunParticipant @bosun58570]

I’m no expert, but as you have to hold the button in, could it be a failed relay?

[michael27]

On 5 November 2024 at 06:51 michael27 Said:

Hi

i I have the above lathe which has suddenly stop working.I have change both fuses, and the green/ red on/off button still not working unless you hold the green button in
my guess that the printed circuit board as blown?

As anybody come a cross this before or can suggest where to look next.

Thanks for any help

Hi Michael,

Sounds very much like the NVR / Emergency Stop switch has failed. The board is OK if holding Green down spins the motor.

NVR switches contain a relay and contact that bypasses the Green button which is momentary.

Pressing the green button starts the lathe and bypasses itself by powering on the relay.    The arrangement creates a No Volt Release (NVR), needed to stop the machine mangling the operator by unexpectedly turning back on after a power-cut.  They’re often combined with the RED mushroom emergency off.

Do a search on Amazon for NVR to identify a replacement.  (Other sources available, and Chester may hold it as a spare),  Cost under £10, and they look like:

OR same thing with a RED mushroom Emergency STOP on top:

 

OR, maybe the Emergency Off is a separate switch, which might be what your DB10 does. (Two red mushrooms!).

The circuit is much the same.   The NVR relay is, I believe, always inside the RED/GREEN button.

Replacing is usually easy because they are wired in with pull off and push on spade connectors – no soldering.  Before replacing check that these connections are in place.  Not unknown for the crimps to fail or a carelessly fitted spade to vibrate loose.

Replace like-with-like a step at a time.  Don’t rip several wires off and expect to remember where they came from!

Hope that makes sense, I’m poorly this morning and am going back to bed.

Another recent thread discussed the same problem in more detail.  Perhaps another kind member will find it for you.

Dave

 

 

 

 

[michael27Participant @michael27]

Hi all

update on above I have fitted a new switch still wil only work holding green switch in

done a continuity tested from the 3pin plug and through the switch all the way to motor all is ok, but the A1 wire there is no continuity through the  small red wire.

the wire from both the locations on the switch disappears in the  lathe is this where a relay switch  or something be  for could be for coil be?

Have not got round to pulling all lathe away from wall yet as this is not that easy to do

Hope this makes sense

[MacolmParticipant @macolm]

Check interlock switches on covers, chuck guard etc. There needs to be continuity through all of these before the green button power relay will latch ON.

[michael27Participant @michael27]

Hi

Thanks for replay, would it cause  any damage if I just loop the A1 wire on the switch to prove  that it works the on/off switch correctly ?

 

 

[MacolmParticipant @macolm]

That is indeed how to check it. Best not to use it like that, though.

[michael27Participant @michael27]

Thanks for all your replies

finally found the cause of the problem

the spring in limit switch for gear guard stuck clean re greased put back and  all works again

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