Series parallel motor starter with auto off proximity sensor

[vitoboy]

Hi All
A while ago a customer asked us to move a 1970s single phase corn mill and return it to use.
It had an old series parallel starter with a lever on it ..which we replaced with a crompton controls series 3000 starter...all good and running.

Now they had another ip rated box attached to the original starter with a 230v relay and a brodersen unic xw electronic timer (release delay,on pulse,off pulse,on off pulse) plus a 230v 2 wire proximity sensor on the mill hopper....they said it was used to switch the mill off when the corn ran out to prevent damaged rollers and they would ideally like it reinstated.
Problem was this stuff was bypassed when we got to it (the proximity sensor was found to be u/s).. and we have of course changed the starter to series 3000.

So I have done a couple of drawings .. but I can't seem to get it to work.

I'm thinking that the xw time delay is there to start the motor via the relay and get it milling until the proximity sensor see's the corn ...holding on the relay itself.. then drops out leaving the proximity sensor keeping it running ... when the proximity stops seeing corn it drops the relay stopping the motor.

So... am I on the right track here..can anyone give me a sketch for this..?..I can post more details on each item if required as I have the series 3000 diagram the relay diagram the unic xw diagram. .the proximity sensor is just 2 wire..

Cheers

Vito

 

[Lucien Nunes]

If the sensor does not have an adjustable off delay itself, then I would think that the sensor triggered the timer (configured as an off delay) and kept it triggered, and the timer output alone controlled the starter. That would enable it to ride out any gaps in the corn flow including at start-up as you mention, before timing out and stopping.

When the motor had a manual drum-starter, the timer contacts would have held the NVR coil; now they would presumably be in series with the stop button. The trick is in how to trigger the timer to begin with, to allow it to start. With the manual starter, a contact in the start position might have been used. I'm guessing here, by all means post some pics to help us out.

FWIW we had one of these single-phase 2-stage starters under scrutiny a fortnight ago, where the NTC thermistor for the run contactor had broken apart. Also, if you have the old drum starter, I'm needing an example for the museum!

 

[westward10]

Yes what are the chances.

Motor starter help.

Hi all, thanks again for any input. I have been asked to look at this starter as motor starts ok, but when switches over to run motor stops and starter just hums. First of all like I’ve said in previous posts I haven’t had a lot of experience with motors/ starters etc Am I right in thinking this...

www.electriciansforums.net

 

[vitoboy]

The proximity sensor does not have a delay.

I have the cover of the old starter with its diagram on the inside I could post...your welcome to the bits.

I will post some pics and my attempt drawing tomorrow.

Thanks for your interest!

 

[FarmersFriend]

If you search for a company called “proxyswitch” they make a really simple, robust time delay switch in the U.K. I use these on most of the grain handling installs I do. They make low voltage and mains versions.
On a side note I priced a 68A series parallel Crompton starter from CEF & KEW, KEW where £200 cheaper!

 

[FarmersFriend]

If you search for a company called “proxyswitch” they make a really simple, robust time delay switch in the U.K. I use these on most of the grain handling installs I do. They make low voltage and mains versions.
On a side note I priced a 68A series parallel Crompton starter from CEF & KEW, KEW where £200 cheaper!

Sorry but I don't know how to edit posts! company is called proxswith, no Y.
DOL 40 Series are the other ones we use for grain handling installations.
[automerge]1577183967[/automerge]

If the sensor does not have an adjustable off delay itself, then I would think that the sensor triggered the timer (configured as an off delay) and kept it triggered, and the timer output alone controlled the starter. That would enable it to ride out any gaps in the corn flow including at start-up as you mention, before timing out and stopping.

When the motor had a manual drum-starter, the timer contacts would have held the NVR coil; now they would presumably be in series with the stop button. The trick is in how to trigger the timer to begin with, to allow it to start. With the manual starter, a contact in the start position might have been used. I'm guessing here, by all means post some pics to help us out.

FWIW we had one of these single-phase 2-stage starters under scrutiny a fortnight ago, where the NTC thermistor for the run contactor had broken apart. Also, if you have the old drum starter, I'm needing an example for the museum!

I have to service a few of the manual rotary ones each year, if I replace any I will let you know