I want to replace four of the combined Push switch/Circuit Breakers used on my Parker 31 Main Switchboard. The plastic thread around the button which pushes through the panel and is secured by a knurled nut has broken and I think three others are going that way. I could just glue the switch to the back of the panel but I would rather replace the switch properly.

The part number for the single pole switch/circuit breaker is 'Weber T12-221' which I have confirmed with RS components and Farnell but they don't stock these but do stock the Circuit Breaker only variant (T12-211) made by Schurter but that doesn't operate as an On-Off switch.

I have also found that a Chinese company TNE also appear to make the T12-221 (and I think make the ones Schurter list). But they don't appear to be available in the UK. I have found them on Ebay either from the US, Germany or Poland.

So my question is has anyone else had the issue and managed to find a UK supplier, an alternative, or possibly just gave up and changed the whole switchboard in which case did they keep any of the old switches that were still Ok and did they want to sell them?

This is second attempt as I tried adding photos before and it crashed so will try adding photos after text.

All the Best and roll on Spring

Peter

Ever thought about changing them for sub - miniature toggle switches?

Regards

Grahame

p31/4

Thanks for reply and hello, I saw your entry about a stuck keel. I have never had the ram apart as it was all serviced shortly before I bought the boat so I have just been greasing the wires and blocks etc. The only problem I have had so far was a hydraulic leak which eventually turned out to be nothing more than a slack nut. I would just say be careful when looking at technical articles on the P31 Hydraulic Keel but most are for P325/335's which have a different setup to the P31. But I now intend to check the rams keel side fixings before I relaunch for the summer. I hope you have managed to resolve everything now and I think all P31 owners would be interested to hear any advice you have to avoid the same problem.

I also wanted to say Hi because we are planning to head along the south coast to the Scilly Isles if possible this summer and may well call in to Lyme Regis.

Regarding my switchboard, It would be quite easy to change to standard toggle switches as the panel inserts are the same, and I have a few in my electrical tool box but, the problem would then be that I would also have to add separate fuse holders or circuit breakers for each switch, and there just isn't the room to do that.

I understand you have an early P31 so not sure if they had the same custom made 'Parker Lifting Keel' switchboard but it has a lot squeezed onto the one panel.

I have tracked down replacements on Ebay but only available, at quite a cost, from Germany or Poland. I have also found that a wholesale distribution site lists them at an unidentified warehouse somewhere in the midlands. They only seam to deal with VAT reg companies but I am going to try phoning tomorrow. If they stock them in the UK for wholesale then surely someone must be selling them on in retail. just need to discover who.

If anyone is wondering these are Schurter Series T12-221 SPST switched circuit breakers and the board uses various fused ratings from 2 Amps to 16 Amps.

All the Best

Peter P31/#29

Aren’t these the correct ones

I wish it was. The switchboard on my P31 uses a unit that combines a thermal circuit breaker (Schurter Series T12-221 SPST) ,with a push button switch that is rated for 5000+ on off operations. The advantage being that one unit combining both takes up less space on the rather cramped switchboard than having a switch on each circuit plus an operate fuse holder or circuit breaker on each as well. A standard circuit breaker only turns off by an overload like a fuse and is turned back on by pushing the button back in. Even if they have a test facility to trigger the circuit breaker that is not rated for repetitive use as a switch. Schurter make a similar circuit breaker only version of the the T12 series the T12-211 which is much cheeper but for the above reasons wont work. I haven't found anything similar by any other manufacturer.

I toyed with idea of completely rebuilding and rewiring the whole board adding additional inserts to have separate fuses and switches but it would get very cramped and messy.

But I have now found a supplier that can supply the T12 221 units for £20 each (as against around £40- £50 including postage on Ebay). I will update this post if they are OK when I get them.

But thanks for the suggestion.

All the Best

Peter

Regards Paul

All the Switches on my Parker 31 switchboard are ‘Webber’ T12-22. They double up as both switch and thermal circuit breakers. They now appear to be made by a Chinese company TNE for a Swiss company Schurter. They are button switches secured to the front of the switch panel through a hole with a knurled nut over a plastic thread around the button shaft. That plastic thread had broken on four switches leaving the switch loose in the hole. At first the only place I could find these was on EBay with prices between £45 and £55 listed in Poland and Germany. I could find no alternative combined switch/circuit breaker to fit.

However, a wholesaler directed me to ‘Transfer Multisort Electronik Ltd ‘(TME) who have a warehouse in UK and that is where I ordered them from at around £18 each. But weirdly these came from Poland via Germany so it took a couple of weeks to get here. Here is the link to a search for the 16A version but they come in many current ratings.

https://www.tme.eu/gb/ka...:spst;current-rating:16a 

Be sure to buy just the basic T12-221 SPST switch/circuit breakers as the other variations including switch covers etc. can be quite costly.

They are a perfect fit except that the new ones have black buttons with the current rating on the end of the button whereas the old ones had red buttons.

A couple of observations. The spade fittings on one side are bolted with tiny M1brass screws to a thin brass bus bar. The holes in the spade terminals are too small so I had to drill them out to 1mm. Otherwise they all fitted out of the box.

I think that when one of the button switch threads break and a switch comes loose it transfers the pressure of pushing in the switch via the bus bar to the next switch. So, if one thread breaks the bus bar holds it in but transfers the pressure of pushing the switch in to the next switch with the potential to break that thread. So it is a good idea to sort this out if it happens or one switch after another might break.

I could see as I took the offending switches out that some had broken before and had the adjusting nut from inside removed so that they could be mounted tight to the back of the panel to show enough remaining thread for the nut. A possible fix if it’s a first break of the thread. Failing that you could glue the switches to the back of the switchboard but that would cause significant problems if you wanted to change them in the future.

Hope that helps anyone with a similar issue.

Peter and Annette P31/#29.