GN19-12ST/1000A Indoor High-voltage Isolating Switch, with CS6 dual operating mechanism, 10kV cabinet-mounted knife switch

The GN19 series are indoor high-voltage disconnectors with a rated voltage of 10-24kV and AC 50Hz. They are specially used for circuit switching and power isolation under voltage and no-load conditions, have no arc extinguishing capability, and must be equipped with manual operating mechanisms such as CS6-1.

Core parameters and model meaning

Rated voltage: Common models are GN19-10/12/24 (corresponding to 10kV/12kV/24kV respectively), and some models support a wide range of 6-10kV;

Rated current: Standard specifications are 400A, 630A, 1000A, 1250A (only 630A for 40.5kV level);

Withstand capability: Take GN19-12/630 as an example, the short-time withstand current (4s) is 20kA, and the peak withstand current is 50kA; the 1250A level can reach 40kA/100kA;

Model rules: GN19-voltage/current - dynamic stability value, the suffix "C" means through-wall type (C1/C2/C3 distinguish the bushing side), "G" means grounded type, "Y" means live display;

Structural forms: Flat-mounted type (double post insulators), through-wall type (one post and one bushing), with earthing switch type (single/double earthing).

Structure and working principle

Conductive system: Each phase of the knife blade is composed of two slot-shaped copper plates, and the contact pressure is maintained by springs at both ends; models above 1000A are equipped with magnetic locking plates, which use the electromagnetic force of short-circuit current to enhance the clamping force and improve dynamic and thermal stability;

Transmission mechanism: The operating mechanism drives the base main shaft to rotate, and drives the three-phase knife gates to switch synchronously through the crank arm and pull rod insulators;

Limit design: Limiters (stops) are installed on the base to ensure accurate end positions of opening/closing;

Insulation support: The flat-mounted type has two post insulators per phase, and the through-wall type has a porcelain bushing on one side to adapt to the wall.

Main functions and operation specifications

Isolate power supply: Form an obvious visible disconnecting point after opening the gate to ensure maintenance safety;

Switch lines: Used for changing operation modes such as double busbar switching;

Small current operation: Can switch voltage transformers, arresters, bus charging current, no-load transformer excitation current (usually ≤2A) and short cable capacitive current;

Prohibit load operation: It is forbidden to switch load current or short-circuit current, and it is necessary to confirm that the circuit breaker has been disconnected before operation;

Operation sequence: When powering on, "close the disconnector first, then close the circuit breaker"; when powering off, "open the circuit breaker first, then open the disconnector".

Usage environment and installation requirements

Environmental conditions: Altitude ≤1000m (some high-altitude models are suitable for higher altitudes), temperature -30℃~+40℃, daily relative humidity ≤95%/monthly ≤90%, no severe vibration and chemical corrosion;

Installation height: The switch shaft is 2.2~10m from the ground, and the center of the manual operating mechanism handle is 1~1.3m from the ground;

Safety spacing: The insulation distance between live parts and the ground in the open/closed state is ≥300mm, and the phase-to-phase distance is ≥150mm;

Fixing method: Can be installed horizontally or vertically on walls/metal frames, through-wall type needs to cooperate with corresponding wall bolt specifications (brick wall ≥90mm deep, concrete wall ≥75mm deep);

Interlock protection: Models with earthing knives need to have mechanical interlocks to ensure that the earthing knife can be closed only after the main knife is opened.

Selection and maintenance points

Selection basis: Select the specific model according to the system voltage, continuous working current, short-circuit dynamic and thermal stability value and installation scenario (flat-mounted/through-wall/earthing/pollution-resistant);

Daily maintenance: Must be carried out after power off and voltage test; check insulator damage, contact ablation and fastening conditions, apply power composite grease after cleaning the contact surface;

Fault handling: Replace the contacts if they are severely deformed or the springs have residual deformation; adjust the connecting rod length and lubricate the transmission parts if the operation is stuck.