In every electrical system, two conductors quietly play a crucial role in keeping operations safe and stable, Neutral and Earth. Though they’re often out of sight, their connection forms the backbone of fault protection, voltage stability, and system compliance. When this connection is compromised, the risks can be serious: unpredictable voltages, equipment damage, and even safety hazards. That’s why Transtech developed NEMON, the Neutral to Earth Monitor Operation. This intelligent monitoring solution is designed to detect issues in the Earth-Neutral connection before they escalate. Whether it’s a blown fuse, high resistance, or a missing neutral, NEMON keeps a constant watch, ensuring your three-phase protection system operates safely and reliably.
What is Neutral to Earth Connection
In a typical electrical installation,
- The Neutral conductor carries current back to the source, completing the circuit.
- The Earth conductor provides a safe path for fault current to dissipate, protecting people and equipment.
These two conductors are usually bonded at a single point, often at the main switchboard or transformer, to stabilize the system voltage and provide a reference point for protective devices. This bond is known as the Neutral to Earth connection.
When this connection is intact and functioning correctly, it helps:
- Maintain voltage balance across phases
- Ensure protective devices like circuit breakers and surge protectors operate correctly
- Prevent dangerous voltages from appearing on exposed metal parts
However, when these connections degrade or fail, due to corrosion, loose wiring, or component failure, the consequences can be severe:
- Unpredictable voltages
- Equipment damage
- Increased risk of electric shock
- Fire hazards
Traditional protection devices often overlook these subtle but dangerous faults. NEMON fills this gap by providing continuous, automated monitoring of Earth-Neutral integrity.
What is NEMON?
NEMON stands for Neutral to Earth Monitor Operation. It’s a purpose-built monitoring module designed to work alongside Transtech’s Series 3 Phase Protectors. Its role is simple but vital: to continuously monitor the condition of Earth-Neutral connections and alert operators to any faults that could compromise system safety.
Developed using Transtech’s deep instrumentation design expertise, NEMON is the first of its kind to offer real-time detection of fuse failure, high resistance, and missing neutral conditions, all in one compact, intelligent unit.
How NEMON Works
NEMON uses a combination of low-level, galvanically isolated 10kHz signals and intelligent detection circuits to monitor three key conditions:
- ENPV Fuse Monitoring
NEMON checks the status of the Earth-Neutral Protection Varistor (ENPV) fuse. If the fuse has operated (i.e., blown), NEMON detects the open circuit and triggers an alarm relay. This ensures that protection components are always in working order.
- Neutral-Earth Resistance Monitoring
A healthy Neutral-Earth connection should have a resistance below 10 ohms. NEMON injects a small test signal and measures the resulting voltage to calculate resistance. If the resistance exceeds the threshold, the system is flagged as unsafe, and the alarm relay is deactivated.
- Missing Neutral Detection
Using a clever “pseudo-neutral” technique, NEMON can detect when the Neutral conductor is disconnected. It does this by observing shifts in a balanced resistive/reactive network. If the Neutral is missing, the balance is disturbed, and NEMON responds immediately.
Key Features
- Three Modes of Protection: Monitors L-E / L-N / N-E pathways for full protection coverage
- Advanced Detection Circuitry: For zero-potential conductors (Earth & Neutral)
- Category C / Class III Rated: Ideal for point-of-entry installations
- Self-Resetting Design: Unlimited life spans up to rated kA faults
- Standards Compliant: Meets IEC 61643-1 and AS/NZS 1768:2005
Where Do You Need NEMON?
NEMON is ideal for use in main switchboards, critical infrastructure, and industrial environments where electrical reliability is critical. It’s especially valuable in systems using Transtech’s Series 3 Phase Protectors, where it adds an extra layer of intelligence and safety.
Applications include:
- Manufacturing plants
- Data centres
- Utilities and substations
- Commercial buildings
- Mining and heavy industry
Unlike conventional monitoring systems, NEMON is built to withstand the harsh realities of industrial environments. Its galvanically isolated sensing ensures safe operation even in noisy or high-voltage conditions. And because it’s fully self-resetting, there’s no need for manual intervention after a fault, reducing downtime and maintenance costs.
At Transtech, we believe that safety should never be an afterthought. With NEMON, we’re setting a new standard for Earth-Neutral monitoring, one that’s intelligent, reliable, and built for the future.
Whether you’re upgrading an existing system or designing a new one, NEMON gives you the confidence that your Earth and Neutral connections are always under watch.
Visit our website or contact our team today to learn more about NEMON.