wenty-first century generator sets are equipped with a wide variety of sophisticated sensors, designed to protect critical systems and to provide accurate and timely information to the machine controller, operator and end user.  Sensors for monitoring coolant and oil levels, temperatures and pressures protect the engine from catastrophic breakdown.  Fuel level sensors do more than just enabling the operator to keep the machine running.  They help prevent damage through fuel starvation and environmental damage due to overfilling.  In remote applications, they are increasingly being coupled to telematics and used to detect fuel theft.

How are sensor manufacturers responding to these challenges? John Petersen, Sales and Marketing Manager at UK based sensor specialist, Fozmula, explained:

“We welcome the introduction of automotive standards, quality and development methods; they force us to make continuous improvements across our entire business.  From the suppliers we work with, through design, development, right up-to packing and shipping; all aspects of our business have been analysed and improved. As a result, the business is leaner, more efficient and staff are enjoying the more challenging but rewarding working environment.  Gensets and their components are now developed following full new product introduction, NPI, programmes.  This entails following a disciplined development process focusing on cost, time and quality and employing techniques such as DFMEA, full test plans through to PPAP and ISIR submission.  Far from demotivating we’ve found rising to these challenges has improved job satisfaction and enabled us to attract highly skilled and enthusiastic employees.
This push for quality and reliability has seen a move towards more solid-state sensors i.e. devices without any moving parts such as floats, swinging arms and magnetic switches.  Solid-state liquid level sensor technology is typically based around hydrostatic and capacitance methods of monitoring liquid level.
Fozmula has developed these technologies over the past 25 years with the latest developments concentrating on electrical integrity in the form of electro-magnetic compatibility, reverse polarity, over-voltage and mis-wiring protection.  New IP67 rated connectors such as the industry standard Packard-Metripack and DIN style bayonet connectors are supplemented with the increasingly popular Deutsch DT range.  When it comes to capacitance switches, we’ve added more discrete voltage output and “flip-flop”voltage options and are confident we can offer drop-in replacements for most new and obsolete switches.”

Petersen went on to describe some of the new devices Fozmula has released specifically with their generator set customers in mind:

·        S28x Coolant and Oil Level Switches

A comprehensive range of completely re-engineered capacitance type level switches used to alert users to low coolant or low oil protecting the engine from potentially catastrophic failure.  Customer scan specify thread size, connector type, switching sense, delays, electrical outputs and either brass or 316 stainless steel bodies.


·        T/LL400 Liquid Level Sensor – Extended Temperature Range

Originally intended as an “electronic dipstick” providing continuous level monitoring of engine oil level this rugged device is capable of operating at temperatures between -40 °C and +125 °C so is also finding its way into coolant and hydraulic systems.  With 0-5 V and 0-10 V output versions this range is a popular choice for use with the latest genset controllers.


·        T/LL150 Cut-to-Length Fuel Level Sensor

Some customers don’t have the luxury of knowing precisely what fuel tank design they will need a sensor for until it arrives in their workshop or their service engineer arrives on site.  Fozmula now offers a capacitance type sensor that can be ordered off-the-shelf in standard sizes but can be easily cut-to-length and recalibrated by the customer’s technician.  This feature has enabled one customer to buy sensors with one part number and use them set up their large rental fleet (comprised of gensetsfrom various OEMs and of different shapes, sizes and power) to monitor fuel levels remotely via their telematics system.


·        T/LL360 Liquid Level Sensor - Auto-compensating Capacitance Type

A highly versatile Liquid level sensor featuring innovative auto-compensation for liquids with different dielectric properties.Popular with power generation customers whose applications need to be able to run on a wide variety of fuels.  It has both screw thread and SAE 5-holeflange mountings and a wide choice of electrical connectors. Output options are voltage, resistance or current, each type also offers an optional alarm point.


·        Guided Wave Radar Level Sensors

Fozmula is now owned by US based Rochester Gauges. In addition to Rochester Gauges’ huge portfolio of mechanical gauges, reed switch probes and float switches, Fozmula now has access to sensors based on Guided Wave Radar principles.  These cost-effective sensors offer very high accuracy and resolution independently of the medium’s properties. With outputs including CAN and LIN, in addition to traditional analogue outputs, these devices are ideal for heavy duty applications and fuel theft protection.


·        G/LL63, G/LL64 & G/LL65 Tank Contents Gauges

A range of mechanical float and spiral driven fuel tank contents gauges providing a local display of the liquid level.  Variants include our G/LL65 with two electrical outputs; a continuous signal for fuel level and a level switch to trigger either a high- or low-level alarm. This is perfect for genset day tanks; when the set is running the gauge provides a fuel level signal to the controller.  When the machine is idling operator can see the fuel level without having to switch the machine on.

According to Petersen, including so many customer specifiable options across Fozmula’s extensive range of sensors, switches and gauges is part of the company’s philosophy that “We’ll supply a sensor to suit the application, we don’t expect our customers to modify their machines to accept our sensor”.

More information? www.fozmula.com

Mar 3, 2020
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