Identify Wema-systems bilge float switch?

Hi,

I need to replace bilge float switch made by Wema-Systems. Its a cylindrical unit with three wires that are Black, White and Green. Here's a photo of it:



It is part of a system that has a control module that looks like this:



I can't find any reference to a bilge switch like this and wonder if any of you has a suggestion for a replacement.

Thanks

Richard

Will one of these work? IMO these are about the best.

TEF-GEL - Ultra safety systems - Home page

kchace said:

Will one of these work? IMO these are about the best.

TEF-GEL - Ultra safety systems - Home page

Click to expand...

Thanks for the response. I might be able to use it - I don't need the high water alarm - I have that installed separately. However, one of the problems is that I don't know how my failed switch operates. I don't know what the three wires do. Also - my switch uses thin wires and clearly does not carry the current for the bilge pump. Rather it is wired to the control box I pictured and somehow the three wires control when the pump turns on and off. Unless I convert my bilge pumps to a different system I think i need to find a switch that behaves in the same way as my broken one.

I have emailed Wema and I'm hoping to get something useful from them. I just thought I'd see if any of the forum members recognized the system and could make recommendations.

Thanks again

Richard

You can get them from Fisheries supply.

Bilge Pump Switch - Wema-System | Fisheries Supply

This from their website

OVERVIEW
Wema heavy duty bilge pump switch incorporates 2 float activated reed switches protected from damage and jamming by a stainless steel housing. The reed switches are glass encapsulated, and all electronics are fully sealed within the switch head. The system incorporates a 25 amp relay, and the switch is rated for 20 amp pumps. Water in the bilge causes the magnetic float in the chamber to rise, activating the pump when it nears the top, and shutting the pump off as the water level falls and the float reaches the bottom.
• Easy to assemble
• Easy to maintain
• Wire harness is designed for automatic functioning with a manual override

AusCan said:

You can get them from Fisheries supply.

Bilge Pump Switch - Wema-System | Fisheries Supply

This from their website

OVERVIEW
Wema heavy duty bilge pump switch incorporates 2 float activated reed switches protected from damage and jamming by a stainless steel housing. The reed switches are glass encapsulated, and all electronics are fully sealed within the switch head. The system incorporates a 25 amp relay, and the switch is rated for 20 amp pumps. Water in the bilge causes the magnetic float in the chamber to rise, activating the pump when it nears the top, and shutting the pump off as the water level falls and the float reaches the bottom.
• Easy to assemble
• Easy to maintain
• Wire harness is designed for automatic functioning with a manual override

Click to expand...

Thanks so much for doing the research. Unfortunately, this is just a regular bilge pump switch with a manual override. It's not a replacement for my switch. This is designed to be placed in series with the bilge pump whereas mine is not. Here's the description I found on this switch:

PBK-12/24 - Wema System - PDF Catalogues | Documentation | Boating Brochures

Thanks again for looking

Richard

Britannia said:

Thanks so much for doing the research. Unfortunately, this is just a regular bilge pump switch with a manual override. It's not a replacement for my switch. This is designed to be placed in series with the bilge pump whereas mine is not. Here's the description I found on this switch:

PBK-12/24 - Wema System - PDF Catalogues | Documentation | Boating Brochures

Thanks again for looking

Richard

Click to expand...

It's possible that I could use a conventional float switch - but I'll need to figure out how to wire it up to the module. I might have to end up experimenting.

Thanks again

Richard

This maybe?

Bilge Pump Switch and Bilge Alarm by WEMA USA, Inc.

If I had to venture a guess, the green is still just a chassis ground for bonding and the black and white are the level sensing resistor.

Tom.B said:

This maybe?

Bilge Pump Switch and Bilge Alarm by WEMA USA, Inc.

If I had to venture a guess, the green is still just a chassis ground for bonding and the black and white are the level sensing resistor.

Click to expand...

Yes - that's the same unit as suggested by AusCan. I might be able to make it work with my current system if I knew how it really works.

Your guess for the wiring seems logical. However, all the wires go into and entirely plastic part of the unit. So there'd be nothing to bond to. There's another thing - a feature of my system that I didn't mention yet. One of the features is that if you flip the switch to manual, just briefly, it will activate the pump, which will continue until the "low water" mark is reached. It will do this even if it's not yet at the "high water" mark. In order to do this I suspect that the unit has two switches - a high and low switch. Most units have two switches but also a relay so that the switch turns on a "high water" and off again at "low water". I suspect that this unit simply provides both switches back to the control module - that's what would be needed for this feature to work. In that case, one wire is probably common (the green?) and the other two would be the two switches.

Now I could conduct an experiment with the module by shorting the various wires to simulate the switch. From that I could probably determine how it all works. Ideally I'd like to get a real replacement part, or at least a known working alternative setup. I'd rather not cobble something together based on partial knowledge - especially when we're talking about a bilge pump!

Richard

Her is a wiring diagram for the Wema bilge pump switch in the above link.

Why don't you give them a call. The folks at Wema have always been helpful when I talk to them.

rochepoint said:

Her is a wiring diagram for the Wema bilge pump switch in the above link.

Click to expand...

Thanks - I had seen that - it confirms that it's designed to be wired inline with the pump.

Richard

HopCar said:

Why don't you give them a call. The folks at Wema have always been helpful when I talk to them.

Click to expand...

I've been exchanging emails with them. For a while I wasn't getting anywhere but in the end got the answer that they don't make the module or switch any more and so I'll have to convert to the PBK and remove the module. I'll only lose that one little feature which isn't really that important. I don't think it'll be that big of a deal.

Thanks for your help everyone. I'm going to place an order for 3 PBKs - two of my old switches have already failed so I assume the third isn't far behind. I'll just replace all 3.

Richard

I know this thread is many years old and the need for the WEMA switch has probably long since past, but I have a NOS WEMA PBK12 identical to the one in the picture at the top of the thread for sale if anyone is interested. PM for details.