Samwha dsp Tense GKT-03F Three Phase Over & Under Voltage Control Relay

The GKT-03F is an analog adjustable, non neutral three phase voltage protection relay engineered to safeguard electrical motors, pumps, and sensitive automated industrial equipment from volatile grid fluctuations. Housed in a compact, modular terminal footprint optimized for 35 mm DIN rail mounting, this specialized controller provides continuous multi fault surveillance. It actively monitors for over voltage, under voltage, phase failure, and improper phase sequence configuration within $3\times380\text{V AC}$ 3 wire network loops.

Key Features

Analogue Precision Setpoint Adjustments: Outfitted with independent potentiometers to manually configure high voltage limits ( $HV$ : 400V–510V) and low voltage limits ( $LV$ : 260V–370V), with option selections to completely disable either protection ring if required.
Adjustable Delay and Reset Timers: Features dual rotary knobs to customize the system’s Delay Time ( $DT$ : 0.1–20 sec) to avoid nuisance trips from brief grid dips, along with a programmable Reset Time ( $RT$ : 0.1–20 sec) to guarantee grid stabilization before system reconnection.
Phase Sequence & Failure Protection: Automatically blocks system initialization if the incoming three phase configuration is reversed or if an active phase drops completely, suppressing the risk of multi phase motor damage.
4 LED Diagnostic Status Array: Outfitted with vibrant front facing LED indicators labeled for clear fault tracking identifying Low Voltage ( $LV$ ), High Voltage ( $HV$ ), Phase Sequence/Failure errors, and normal Relay status.
Non Neutral Terminal Isolation: Engineered explicitly for three wire networks ( $L1, L2, L3$ ) to operate without a neutral loop hookup, serving as an ideal safety solution for heavy isolation installations.

Technical Specifications

Feature	Specification
Model Number	GKT-03F
Brand Recognition	Samwha dsp / Tense Electronics
Operational Line Voltage ( $U_n$ )	$3 \times 380\text{V AC}$ @ $50 / 60\text{ Hz}$ configuration
Over Voltage Threshold ( $HV$ )	$400\text{V} - 510\text{V AC}$ (Adjustable / Turn-Off option)
Under Voltage Threshold ( $LV$ )	$260\text{V} - 370\text{V AC}$ (Adjustable / Turn-Off option)
Delay ( $DT$ ) & Reset ( $RT$ ) Ranges	$0.1\text{ sec.} - 20\text{ sec.}$ independent calibration dials
Output Contacts Configuration	SPDT Contact rated at $5A / 250\text{V AC}$ (Resistive Load)
Form Factor Compatibility	Standard 35 mm DIN-Rail Snap-on Enclosure
Operating Temperature Window	$-20^\circ\text{C} \dots +55^\circ\text{C}$

Applications

Industrial Pump & Extractor Protection: Safeguarding three phase hydraulic or submersible water pump stations against overheating risks following partial phase failure or severe grid drops.
Motor Control Centers (MCC): Shielding conveyor motors, fans, and heavy production machine components from counter rotation failure due to improper sequence wiring during facility maintenance.
HVAC Chiller Compressor Loops: Preventing expensive terminal burnouts in commercial scroll or screw refrigeration units during under voltage brownout seasons.
Main Switchgear Protection Panels: Integrating into centralized incoming distribution tiers as a master safety gatekeeper before routing power to lower branch circuits.