S3H Holding Tank Sender
- Unit price
- / per
Specifically designed for black or grey water tanks
Constructed from corrosion-resistant 316 stainless steel
Features a 1 1/4" BSP thread fitment for secure installation
Compatible with both 12v and 24v electrical systems
Operates on a 240 ohms (empty) to 30 ohms (full) resistance range
Engineered for easy installation, removal, and cleaning
Protective cage design for enhanced durability in holding tank environments
The Wema S3H Holding Tank Sender is an advanced sensor designed for black and grey water tanks in marine, recreational vehicle or static applications. It incorporates the same reliable electronics as the S3 and S5 senders, but with an added protective cage surrounding the float. This cage is crucial for safeguarding the float mechanism in the challenging environment of holding tanks.
Manufactured from high-quality 316 stainless steel, the Wema S3H holding tank sender has been the preferred choice of major British and European boat builders for over four decades. Its robust construction ensures longevity and reliability in harsh marine conditions. The sender operates on a simple yet effective principle: twin magnets in the float activate a series of reed switches securely housed within a doubly insulated stainless steel tube. This time-tested design has proven its durability and accuracy over years of use in various marine vessels.
As technology has progressed, so too has the Wema S3H holding tank sender. Advancements in reed switch technology have allowed for a significant increase in the number of switches that can be fitted inside the sender. This improvement translates to enhanced resolution, meeting the demands of modern digital displays and providing more precise tank level readings. The increased accuracy is particularly beneficial for efficient waste management on board.
A key feature of the Wema S3H holding tank sender is its removable 316 stainless steel cage. This cage serves as a critical barrier, protecting the float mechanism from the harsh contents of black water tanks. The removable design allows for easy maintenance and cleaning, ensuring the sender continues to function optimally over time. This feature is especially valuable in holding tank applications where regular maintenance is essential for proper functioning.
All Wema S3H holding tank senders operate on a 240-30 ohms resistance range, providing consistent and reliable readings across various tank sizes. This standardized resistance range ensures compatibility with a wide range of marine gauges and monitoring systems.
NOTE: It is crucial to ensure that paired senders and gauges have matching resistance ranges for accurate readings and system compatibility.
For those requiring different output options, Wema also offers several sizes of holding tank senders with a 0-10 volt output, providing flexibility for various marine electrical systems and monitoring preferences.
The Wema S3H holding tank sender's robust construction, precise measurements, and easy maintenance make it an ideal choice for boat owners and manufacturers alike. Whether you're outfitting a new vessel, vehicle or upgrading an existing system, the Wema S3H holding tank sender provides reliable, accurate tank level monitoring for your marine sanitation needs.
Simply connect one wire to earth and the other wire to the sensor cable on the gauge.
Simply screw clockwise into a 1.25" BSP thread.
Tighten by hand and then nip tight no more than:
Steel Flange: 9 Nm ±1
Nylon Flange: 7 Nm ±1
S3H Holding Tank Sender
- Unit price
- / per
European vs American Resistance
What's the difference between the European and American resistance specifications?
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European spec. products work on a variable resistance from 0 ohms at empty to 190 ohms at full.
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American spec. products work on a variable resistance from 240 ohms at empty to 30 ohms at full.
[Note: US resistance is known as US purely due to the fact that, historically, this resistance range was used more by US boat builders and EU resistance was favoured by European OEMs – a bit like 240v/110v AC, PAL/NTSC etc. – today both resistance ranges are used on both sides of the Atlantic. There is no advance or disadvantage to either resistance range.]
Why is the resistance Important?
Both the sender and gauge must have the same resistance values.
If you pair an American and European sender and gauge then the gauge will read backwards.
If you are converting an analogue sender to a digital network - like NMEA2000 - then you will also need to know the resistance value of the sender in order to get the correct converter and set it correctly in the NMEA network.
What Specification Is My Gauge?
To test if your gauge is working properly or to find out if it's European or American specification:
If you have access to the wires on the back of the gauge;
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Power the gauge off
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Disconnect the black wire (sender)
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Power the gauge on
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If it's an American gauge the needle will show EMPTY
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Touch the black wire to earth, the needle will go to FULL
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If it's a European gauge the needle will show FULL
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Touch the black wire to earth, the needle will go to EMPTY
If you don't have access to the back of the gauge;
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Disconnect the two wires in the loom that attach to the sender.
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Touch the two wires together (on gauge side of loom!)
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If it's an American gauge the needle will show EMPTY
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Touch the black wire to earth, the needle will go to FULL
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If it's a European gauge the needle will show FULL
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Touch the black wire to earth, the needle will go to EMPTY
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What Specification Is My Fuel / Water / Holding Tank Sender?
To test if your sender is working properly or to find out if it's European or American specification:
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Disconnect the two wires on top of the sender.
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Remove the sender from the tank.
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Connect the wires on the sender to a multimeter.
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Set the multimeter to resistance [Ω ohms]
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Move the float to the top of the sender and take a reading on the multimeter:
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At the top of the sender (full) the resistance should be:
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European specification - 190 ohms
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American specification - 30 ohms
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Move the float to the bottom of the sender and take a second reading:
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At the bottom of the sender (empty) the resistance should be:
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European specification - 0 ohms
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American specification - 240 ohms
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Specifically designed for black or grey water tanks
Constructed from corrosion-resistant 316 stainless steel
Features a 1 1/4" BSP thread fitment for secure installation
Compatible with both 12v and 24v electrical systems
Operates on a 240 ohms (empty) to 30 ohms (full) resistance range
Engineered for easy installation, removal, and cleaning
Protective cage design for enhanced durability in holding tank environments
The Wema S3H Holding Tank Sender is an advanced sensor designed for black and grey water tanks in marine, recreational vehicle or static applications. It incorporates the same reliable electronics as the S3 and S5 senders, but with an added protective cage surrounding the float. This cage is crucial for safeguarding the float mechanism in the challenging environment of holding tanks.
Manufactured from high-quality 316 stainless steel, the Wema S3H holding tank sender has been the preferred choice of major British and European boat builders for over four decades. Its robust construction ensures longevity and reliability in harsh marine conditions. The sender operates on a simple yet effective principle: twin magnets in the float activate a series of reed switches securely housed within a doubly insulated stainless steel tube. This time-tested design has proven its durability and accuracy over years of use in various marine vessels.
As technology has progressed, so too has the Wema S3H holding tank sender. Advancements in reed switch technology have allowed for a significant increase in the number of switches that can be fitted inside the sender. This improvement translates to enhanced resolution, meeting the demands of modern digital displays and providing more precise tank level readings. The increased accuracy is particularly beneficial for efficient waste management on board.
A key feature of the Wema S3H holding tank sender is its removable 316 stainless steel cage. This cage serves as a critical barrier, protecting the float mechanism from the harsh contents of black water tanks. The removable design allows for easy maintenance and cleaning, ensuring the sender continues to function optimally over time. This feature is especially valuable in holding tank applications where regular maintenance is essential for proper functioning.
All Wema S3H holding tank senders operate on a 240-30 ohms resistance range, providing consistent and reliable readings across various tank sizes. This standardized resistance range ensures compatibility with a wide range of marine gauges and monitoring systems.
NOTE: It is crucial to ensure that paired senders and gauges have matching resistance ranges for accurate readings and system compatibility.
For those requiring different output options, Wema also offers several sizes of holding tank senders with a 0-10 volt output, providing flexibility for various marine electrical systems and monitoring preferences.
The Wema S3H holding tank sender's robust construction, precise measurements, and easy maintenance make it an ideal choice for boat owners and manufacturers alike. Whether you're outfitting a new vessel, vehicle or upgrading an existing system, the Wema S3H holding tank sender provides reliable, accurate tank level monitoring for your marine sanitation needs.
Simply connect one wire to earth and the other wire to the sensor cable on the gauge.
Simply screw clockwise into a 1.25" BSP thread.
Tighten by hand and then nip tight no more than:
Steel Flange: 9 Nm ±1
Nylon Flange: 7 Nm ±1