S3 Fuel and Water Sender
- Unit price
- / per
Wema S3 Fuel and Water Senders are available in a comprehensive range of lengths, spanning from 150mm to 1600mm, catering to various tank sizes and applications. These versatile senders are designed to accurately measure fuel, water, and other liquid levels in tanks.
Two standard resistance ranges are offered to accommodate different gauge systems:
- 0-190 ohm: Primarily used in European gauges
- 240-30 ohm: Commonly employed by American gauge manufacturers
It's crucial to ensure that senders and gauges have matching resistance ranges.
The Wema S3 Fuel and Water Sender demonstrates exceptional versatility, being suitable for use with oil and various other liquids. For unique or unusual applications, we recommend contacting our experts for confirmation and guidance.
Manufactured from high-quality 316 stainless steel, these robust senders have been the preferred choice of major British and European boat builders for over four decades. The Wema S3 operates on a simple yet effective principle: twin magnets in the float activate a series of reed switches securely housed and doubly insulated within the stainless steel tube.
Continuous improvements in reed switch technology have allowed for significant enhancements in sender performance. Modern Wema S3 senders now incorporate a greater number of switches, resulting in improved resolution to meet the demands of contemporary digital displays.
For applications requiring even greater precision, we offer high-resolution senders in lengths from 150mm to 400mm. These advanced models feature switches placed at approximately 10mm intervals, compared to the standard 20mm spacing, providing enhanced accuracy and clarity, especially in shallow tanks.
The reliability of S3 senders has been proven across various industries. Wema technology is widely adopted by major European truck and bus manufacturers, as well as in off-road and military vehicles, attesting to its durability and performance in demanding environments.
To accommodate specialised requirements, we offer custom options including:
- Extended sender lengths
- Alternative outputs (0-5v, 0-10v, 4-20mA)
- Bespoke solutions for unique applications
For more information on these options, please contact our team.
Beyond its primary function as a liquid level sensor, the Wema S3 Fuel and Water Sender can be adapted for use as a position sensor. This is achieved by mounting the sender to a stationary part and attaching the float to a moving component, enabling precise position measurement in various mechanical systems.
[Please note: the code 001300 refers to the S3 head]
Torque Settings for Wema S3 Fuel and Water Sender Installation
Proper installation is crucial for optimal performance and longevity of the Wema S3 sender. When mounting the sender (with o-rings in place) into a flange, adhere to these recommended torque settings:
- Steel Flange: 9 ± 1 Nm
- Nylon Flange: 7 ± 1 Nm
Following these torque specifications ensures a secure, leak-free installation while preventing damage to the sender or flange. Always use a calibrated torque wrench for precise tightening.
Simply connect one wire to earth and the other wire to the sensor cable on the gauge.
S3 Fuel and Water 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;
-
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
-
-
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
-
Touch the black wire to earth, the needle will go to EMPTY
-
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
Your details are protected and safe with us.
316 stainless steel
1 ¼" BSP thread
0-190 ohms or 240-30 ohms
IP67
Simple to install and remove
Very reliable
Lengths from 150mm - 1600mm +
The choice of shipping options is calculated at the checkout.
The price and available shipping options will depend on your location as well as the size and weight of your order.
If you choose 'free delivery' or some Royal Mail services, the order may not be trackable for the duration of the journey and only show tracking events when the order is shipped and when it is delivered.
We aim to dispatch all morning (GMT) orders the same day and all orders received afternoon or at weekends the following business day.
Once your order has shipped you will be notified by email.
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Wema S3 Fuel and Water Senders are available in a comprehensive range of lengths, spanning from 150mm to 1600mm, catering to various tank sizes and applications. These versatile senders are designed to accurately measure fuel, water, and other liquid levels in tanks.
Two standard resistance ranges are offered to accommodate different gauge systems:
- 0-190 ohm: Primarily used in European gauges
- 240-30 ohm: Commonly employed by American gauge manufacturers
It's crucial to ensure that senders and gauges have matching resistance ranges.
The Wema S3 Fuel and Water Sender demonstrates exceptional versatility, being suitable for use with oil and various other liquids. For unique or unusual applications, we recommend contacting our experts for confirmation and guidance.
Manufactured from high-quality 316 stainless steel, these robust senders have been the preferred choice of major British and European boat builders for over four decades. The Wema S3 operates on a simple yet effective principle: twin magnets in the float activate a series of reed switches securely housed and doubly insulated within the stainless steel tube.
Continuous improvements in reed switch technology have allowed for significant enhancements in sender performance. Modern Wema S3 senders now incorporate a greater number of switches, resulting in improved resolution to meet the demands of contemporary digital displays.
For applications requiring even greater precision, we offer high-resolution senders in lengths from 150mm to 400mm. These advanced models feature switches placed at approximately 10mm intervals, compared to the standard 20mm spacing, providing enhanced accuracy and clarity, especially in shallow tanks.
The reliability of S3 senders has been proven across various industries. Wema technology is widely adopted by major European truck and bus manufacturers, as well as in off-road and military vehicles, attesting to its durability and performance in demanding environments.
To accommodate specialised requirements, we offer custom options including:
- Extended sender lengths
- Alternative outputs (0-5v, 0-10v, 4-20mA)
- Bespoke solutions for unique applications
For more information on these options, please contact our team.
Beyond its primary function as a liquid level sensor, the Wema S3 Fuel and Water Sender can be adapted for use as a position sensor. This is achieved by mounting the sender to a stationary part and attaching the float to a moving component, enabling precise position measurement in various mechanical systems.
[Please note: the code 001300 refers to the S3 head]
Torque Settings for Wema S3 Fuel and Water Sender Installation
Proper installation is crucial for optimal performance and longevity of the Wema S3 sender. When mounting the sender (with o-rings in place) into a flange, adhere to these recommended torque settings:
- Steel Flange: 9 ± 1 Nm
- Nylon Flange: 7 ± 1 Nm
Following these torque specifications ensures a secure, leak-free installation while preventing damage to the sender or flange. Always use a calibrated torque wrench for precise tightening.
Simply connect one wire to earth and the other wire to the sensor cable on the gauge.