EMI filter

10-10-20

I need an EMI filter folks, my booster pump is creating electrical noise and causing other devices to go offline. It already has a filter fitted within the control box, but I'm guessing that it's bust from the heat as it's 17 years old. I recall that EMI filters were available years back, a plastic can type arrangement with three wires coming out, but I can't seem to source them from electrical suppliers around here.

Where might I pickup a generic filter or is RS my best bet?

kirk.

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kirk.

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Dave_D_Rave

Try and replace like for like if possible.

By obtaining a generic filter this may or may not solve the issue

The filter on the pump has been specifically designed to minimise the the effects from the pump.

Would you have a photo of the filter by any chance ?

10-10-20

It's a pig to get in at, but I know that it's wired in series with the motor on the neutral (only two terminals), so must be a basic coil and cap variant. Any of the ones online are on the L and N, which is better for EMI anyway. I'll see if I can reach it today.

10-10-20

Pah! This is the part, I think mine is a 7uF:

https://theshowerdoctors.ie/product-category/parts-and-spares/shower-pump-parts-and-spares/

The four push connectors on the top are actually just two and two shared.

So this is a actually a start capacitor and not an EMI capacitor, would I be correct? So given that the pump is functional, can I go ahead and install an EMI filter in series with L & N before this...? I think so.

2011

https://www.boards.ie/discussion/2058313773/emi-filter

What brand of pump is it? You may be able to get a replacement.

I have found this crowd to be good for pump parts:

https://www.domesticpumps.ie/

10-10-20

https://www.boards.ie/discussion/comment/121114545#Comment_121114545

Yes, I found the part (posted above), but that's listed as the 'starting cap' and not an EMI cap. I'm not sure that it will resolve the EMI issue, so considering getting a specific EMI filter to add onto the pump as close as I can mount it.

Dave_D_Rave

EMI filters are made up of capacitors and inductors which are connected in series and parallel.

If the component you are looking at is a Capacitor only like the product you have linked above then this is a start capacitor as you have noted.

An EMI filter will look like the attached take note of the schematic showing the caps and inductors.

2023-09-16_21h05_19.png

10-10-20

https://www.boards.ie/discussion/comment/121120144#Comment_121120144

That one is roughly what I'm looking for as it has the class x and class y caps to earth. Just seems to be tricky to get hold of em. Might try sorce one from an appliance store as they appear to keep them as spares.

whizbang

Its more likely you have a bad (corroded/loose) connection somewhere along the line..

10-10-20

https://www.boards.ie/discussion/comment/121145604#Comment_121145604

Hi, thanks. I've inspected the pump wiring, it's solid that I can tell. I'll try a closely coupled EMI filter if I can source one and see if it improves matters.