Relay replacement

[Sea Drummer]

Where can i get a replacement one of these, any ideas ?

[Graham.]

Looks pity standard item. This would do if you snip off the n/o contacts probebly. Not sure why it's described as 4 way

[Graham.]

Now that I looked at it again it's clearly 4 gang, try this one instead.

[Graham.]

Crumbs, that's the same item. I'll give up gracefully, or perhaps you could adapt it.

[Sea Drummer]

Thanks but that one does not have the spec on (and is the wrong size and I want to be careful.I realised I missed off the measurements I have width 28mm , height 25mm depth 12mm

Is is possible to find an exact match based on the numbers on the side

[Sea Drummer]

How can I tell if there latching or non latching relays ?

[mick]

This is probably close enough, but you'd have to snip off the nc contact pins.

SW03503

[tony sayer]

If you put the part number 0 409 04 004 000 into Google it does come up the maker as EBERLE who it seems were taken over by Schrack relays but there doesn't seem to be a direct tie up. Suggest if your certain that the relay is duff then a search on their website may well come up with a very close usable equivalent. What it is not is the cradle series that Graham suggested it were. I've got a box of the bloody things here all

24 volts ones too!..

There seems to be a lot of cross references to TE Connectivity suggest that you look at the size the number of poles the coil volts are 24 volts and its contacts are rated at 10 amps 220 volts so shouldn't be too difficult to come up with a near enough that will replace it.

[Sea Drummer]

Thanks , I did find that part number on Google but did not realize they had been taken over by Schrack and thought it was a site which tried to get your business by responding to the lack of information for hard to get parts. The part recommended by mick looks very close as long as the contacts which are not removed perform the same function. When a relay starts to fail (intermittently), any best way of testing it, I'm thinking multiple times on and off, but mostly the resistance across the contacts, as there appears to have been quite a lot of arching inside the container as there is a black part.

[mick]

For that style of relay there are basically 2 pin layouts. One is usually used for single pole changeover and the other for 2 pole changeover. I don't think many manufacturers do double pole normally open now.

You have to watch the spacing of the main no/c/nc contacts. There are 2 alternative spacings of 3.5mm and 5mm for the pins. The lateral spacing (i.e. between the coil pins and between the different contact set pins) is the same. It would be well worth measuring the pin spacings before you start. :)

[Johnny B Good]

I'm guessing this is a relay in a UPS (probably the change over relay in a line interactive UPS[1]. When my ancient SmartUPS2000 started playing up with intermittent relay trouble, I discovered the fault was a cracked pin on the coil connection solder tag. It had cracked just where it entered the relay base. Applying some sideways pressure to the relay temporarily cleared the fault allowing me to identify which relay I needed to unsolder from the board.

I did briefly consider trying to re-solder the broken tag but gave that idea up as being impractical due to the fragility of such a repair, even if it did seem to work initially. Assuming it even held together long enough to survive being soldered back into the board, it seemed highly likely that it would fail again in rather short order.

I then had a 'brainwave' after giving the problem[2] some more consideration. Said 'brainwave' being to drill a half millimetre diameter hole some 3mm or so into the base right alongside the rest of the tag, tinning it and then pushing a 0.5mm tinned copper wire into the hole and sweating the stronger solder joint so formed to create a new 0.5mm wire tag that *would* survive re-soldering to the board and remain a strong enough joint to avoid premature failure. As it happened, this *did* prove to be an effective and long enduring repair.

I mentioned this because it looks like you've yet to unsolder the relay from the board and when you do, you just might find a similar fault equally amenable to such a repair technique. :-)

[1] Line interactive meaning The UPS can use the rather large and bulky mains transformer primary as an autotransformer to provide buck and boost regulation to cover modest dips and surges without switching directly to the battery powered inverter supply. [2] The problem seemed to be of the class, neatly described by the phrase "For the want of a nail, the ship(?) was lost". It just seemed to be a case of 'replacing a nail' to save the whole "ship" from being scrapped. Quite frankly, I wasn't sure I'd be able to track down a replacement relay without expending a lot of time and effort and extra expense.

[The Other John]

Mixing your metaphors there JBG - for want of a nail the battle was lost. The ship was lost for want of a ha'p'th of tar.

[Johnny B Good]

Thanks TOJ.

I'd already wrote the phrase out when that nagging thought occurred, hence the "(?)" add-on. :-)

It amazes me just how many manufacturers of 'cheap goods' seem blithely ignorant of that last poignant saying. A lot of the early failures in 'cheap goods' could have been so easily avoided by spending just an extra

0.01% or less on the BoM cost.

The stand out classic example of such 'Penny-wise, Pound-foolish' thinking being those packs of disposable lighters in the Pound Shops which fail long before the obvious consumables, butane and flint, run out because they shaved an extra tenth of a penny off the cost of the plastic needed to permit the operating lever some chance of outlasting the 'consumables'.