Faulty switch?

[Rik ShawParticipant @rikshaw]

[Rik ShawParticipant @rikshaw]

My second hand bench drill of oriental manufacture has run well since I bought it until earlier this week when it died on me. I suspected the machines on/off switch had gone faulty as it had been playing up for a couple of days so I bypassed the switch and found the machine ran perfectly OK using the mains wall switch as an on/of switch

I ordered a replacement switch which is identical to the one on the machine right down to the correct part number KJD17B and described as "Start Stop Switch No Volt Release 5pin Switch NVR 2HP/16A with Emergency Stop". The ebay vendor is a business seller who sells lots of these switches.

The new switch arrived today and using my sketch and photos of originally wired switch I fitted the new one this afternoon.

The problem now is that the drill will only run while I hold the green start button down, as soon as I let go the drill stops. Have I been sold a faulty switch?

Rik?

[Brian WoodParticipant @brianwood45127]

Hello Rik,

Daft idea I know, but try 'cancelling' out any interlock stickiness by pushing the OFF button first; it is clearly not holding as it should for RUN

Brian

[Ex contributorParticipant @mgnbuk]

I have had versions of similar NVR switches that have the facility to add extra stop switches.

Does the switch you have just received have a couple of "extra" connections ? If so, try linking these, as this is the connection to the additional normally closed switches.

HTH

Nigel B

[Les Jones 1Participant @lesjones1]

Hi Rik,
Can you post a picture of the diagram on the side of the switch. I think most of these NVR switches are all the same but they put different numbers on the connections. (So there would be no point in me telling you how to connect it using the numbers on the diagrams I have.) Can you also post a diagram of how you have wired it and a picture of the wiring to it. Are there any interlocks on the drill. For example on the belt guard.

Les.

[oldveloParticipant @oldvelo]

hi

It appears that the relay does not hold the contacts in check that the stop button contacts are Normal Closed first.

The coil on the relay may have a fault.

Murphys Law may apply Inter changeable parts will exhibit basic fundamental differences.

Has the motor and the line leads been transposed.

Eric

[Les Jones 1Participant @lesjones1]

Hi Rik,
I have just been looking at these switches on ebay and noticed some have 4 connections and some have 5. How many connections are there on the old switch and the new switch ? IF the new switch has its terminals numbered 13 & 23 IN and 14 & 24 out and it has an extra terminal marked A1 then A1 will probably need linking to terminal 24 Do not make this extra connection before you have posted a picture of the diagram on the switch in case it is different to the diagram I am looking at. All these switches seem to use the same part number even though there are differences.

Les.

[Rik ShawParticipant @rikshaw]

I appreciate the help being offered here. Les, sorry but my OP was incorrect. I have been up the workshop and disconnected the new switch . The NEW switch has 5 pins unlike the old switch which had 4 pins. The new pin is labelled A1.

In the following two photos as requested the new/replacement switch is on the right.

Referring to the numbered pins on the right hand (old) switch the original wiring was 24 blue – 23 blue & white – 14 brown – 13 brown & white where the thinner white piggybacked wires on 13 & 23 probably connect to the laser spotter fitted to the drill.

So the odd man out looks like pin A1 on the new switch. Where do I connect A1 to ?

Rik

Surprisingly there do not seem to be any interlocks/microswitches on the belt guard. The drill works with the belt guard open OR closed.

Edited By Rik Shaw on 25/02/2016 21:07:52

[John RuddParticipant @johnrudd16576]

 

On the basis that there are no interlocks fitted and you have no spare wires, the A1 connection needs connecting to 24…..

Presing the Go button makes the contacts for the Live and Neutral poles, there is already a connection for the coil made internally connected to the Neutral side. Connecting A1 to 24 completes the circuit for the coil and holds the relay in providing the latching action of the switch.

Should the mains be disconnected at the source, the latch drops out requiring a reset by depressing the Go button again……..upon re-instatement of the supply….hence a no volt release function..

I'm sure someone will be along to correct any errors I've made……..

Edited By John Rudd on 25/02/2016 21:11:16

Edited By John Rudd on 25/02/2016 21:14:07

[Les Jones 1Participant @lesjones1]

Hi Rik,
The diagram I was looking at is the same as your new switch so linking A1 to terminal 24 should solve your problem. (As John has already said.)

Les.

[Rik ShawParticipant @rikshaw]

Many thanks to the experts in the "sparks" section hereabouts. A1 to terminal 24 did the trick and my drill is now back in action. Much grateful.

Rik

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