Tense FKV-14 Phase Sequence and Phase Failure Relay

The Tense FKV-14 is a slim profile, multi fault industrial three phase protection relay engineered to safeguard phase sequence dependent electric motors and critical industrial infrastructure from damaging mains anomalies. Operating as an automated line side watchman, this micro modular unit actively monitors the incoming three phase utility supply. It triggers an instantaneous dry contact disconnection if it detects phase failure, a reversed phase sequence, or severe structural voltage asymmetry.

Key Features

Complete Multi Fault Surveillance: Prevents motor burnout or counter rotation mechanical damage by constantly validating phase presence, correct rotational order ( $L1 \rightarrow L2 \rightarrow L3$ ), and phase to phase balance.
Fixed Asymmetry Threshold: Automatically isolates the load circuit if the voltage delta across any of the phases shifts beyond a pre calibrated ~30% asymmetry margin.
Targeted Dual LED Diagnostics Array: Outfitted with clear, color coded front panel visual indicators:
- OUT (Green LED): Direct illumination indicating normal operation where phases are correctly sequence aligned and well within standard voltage limits.
- ERR (Red LED): Provides rapid fault localization; it lights up steady to denote an incorrect phase sequence or flashes at 2 second intervals to signal an asymmetry phase failure error.
Space Saving DIN Rail Module: Utilizes an ultra narrow footprint with an integrated top teal rail clip to allow streamlined installation inside densely packed low voltage switchboards.
Logical Terminal Distribution Layout: Engineered with lower tier input screw terminals for Line and Neutral connections ( $N, L1, L2, L3$ ) and upper tier ports for the integrated output changeover contacts ( $1, 2, 3$ ).

Technical Specifications

Feature	Specification
Model Code	FKV-14
Brand / Manufacturer	Tense Electronics
Nominal Operating Voltage ( $U_n$ )	$3 \times 380\text{V AC} + \text{Neutral}$
Operating Frequency Range	$50 / 60\text{ Hz}$ dual system capability
Asymmetry Tolerance ( $Asym$ )	~30% Fixed Limit
Output Contact Rating	SPDT dry contact rated at 5A / 250V AC (Resistive Load)
Internal Power Consumption	Energy efficient design $< 6\text{VA}$
Safe Working Temperatures	$-20^\circ\text{C} \dots +55^\circ\text{C}$
Manufacturing Origin	Made in Turkey

Applications

Three Phase Motor Protection Systems: Installed in industrial motor control centers (MCC) to shield heavy induction motors and processing pumps from overheating or reverse rotation faults caused by supply network line drops.
Material Handling, Cranes, and Hoists: Serves as a vital directional safety gatekeeper to verify proper phase order before permitting high current magnetic contactors to actuate moving gear assemblies.
Industrial Cooling and HVAC Compressors: Placed on the utility line inputs of high capacity chiller systems to ensure the compressor does not try to start under incomplete or unbalanced phase conditions.
Automation Panel Main Gates: Integrated directly onto incoming distribution rail frameworks to safeguard downstream sub panels and sensitive automation hardware from general phase drops during grid maintenance.