For procurement of the 40.5kV Indoor Disconnect Switch, Dongfa Intelligent provides manufacturer and supplier support for indoor 40.5kV switchgear projects. The GN27-40.5 series is intended to establish an isolation point within the switchgear during maintenance and inspection operations. Product configuration should be considered together with the cabinet structure, operating arrangement, insulation requirements, and available installation space to ensure proper integration into the complete electrical system.
At the 40.5kV voltage class, the insulation condition of an indoor disconnector needs to be considered from more than one direction. The GN27-40.5 series specifies separate insulation levels for the earth/phase condition and the interruptor gap, reflecting the different electrical conditions present within the switchgear.
The GN27-40.5 series provides 185kV lightning impulse withstand and 95kV one-minute power-frequency withstand for the specified earth/phase insulation condition. These values form part of the insulation coordination requirements of the complete switchgear system.
When the disconnect is opened, the separated contacts create an isolation gap that must maintain the required dielectric strength. The specified interruptor gap values are 215kV for lightning impulse withstand and 115kV for one-minute power-frequency withstand.
The two insulation conditions should therefore be reviewed separately when evaluating the 40.5kV Indoor Disconnect Switch for a particular switchgear design.
The GN27-40.5 series provides 630A and 1250A configurations with different short-time and peak withstand current ratings. The applicable version can be selected according to the continuous current and short-circuit conditions of the circuit.
| Parameter | GN27-40.5/630-20 | GN27-40.5/1250-31.5 |
| Rated Voltage | 40.5kV | 40.5kV |
| Rated Current | 630A | 1250A |
| 4s Short-Time Withstand Current | 20kA | 31.5kA |
| Rated Peak Withstand Current | 50kA | 80kA |
| Lightning Impulse Withstand, Earth/Phase | 185kV | 185kV |
| Lightning Impulse Withstand, Interrupter Gap | 215kV | 215kV |
| 1min Power-Frequency Withstand, Earth/Phase | 95kV | 95kV |
| 1min Power-Frequency Withstand, Interrupter Gap | 115kV | 115kV |
| Mounting Holes | 4-18×28 | 4-18×28; some layouts 6-17×20 |
The GN27-40.5/630-20 configuration has a rated current of 630A, 20kA 4s short-time withstand current, and 50kA rated peak withstand current.
The GN27-40.5/1250-31.5 configuration provides a 1250A rated current, 31.5kA 4s short-time withstand current, and 80kA rated peak withstand current.
Electrical ratings are only one part of selecting an indoor disconnect switch. The product also needs to correspond with the physical structure and operating arrangement of the complete switchgear.
The installation drawing should be checked for mounting holes, component spacing, conductor position, cabinet space, and operating arrangement. The GN27-40.5 series uses 4-18×28 mounting holes, while some 1250A layouts may use 6-17×20.
Manual or electric operation and auxiliary switch requirements should be confirmed according to the complete switchgear configuration.
For existing switchgear, the original product model, nameplate, installation drawing, mounting dimensions, connection arrangement, and available cabinet space should be checked before replacement.
The 40.5kV Indoor Disconnect Switch can be incorporated into indoor high-voltage switchgear used in substation incoming sections, transformer-side switchgear, busbar sections, high-voltage distribution rooms, and industrial or mining power systems where electrical isolation is required.
The disconnect switch may remain in one position for an extended period and be operated mainly during maintenance, isolation, or planned switching procedures. Proper installation, operation, and maintenance should therefore be considered throughout its service period.
The 40.5kV Indoor Disconnect Switch uses silver-plated contact surfaces. Contact condition should be maintained according to the applicable operating and maintenance requirements of the switchgear.
Appropriate lubrication, adjustment, and protection of the operating mechanism help maintain mechanical movement during service. Actual maintenance requirements depend on the installation environment and operating conditions.
Technical enquiries concerning product parameters, installation dimensions, operating arrangements, or configuration can receive a response within 1 working day.
For product-related issues after delivery, Dongfa Intelligent provides an initial after-sales response within 24 hours. Support can cover installation clarification, operating questions, configuration checks, and other technical issues related to the supplied product.
For repeat orders or replacement projects using the same switchgear arrangement, previously confirmed product models, technical parameters, and installation information can be referenced during subsequent configuration review.
No. The GN27-40.5 is a 40.5kV Indoor Disconnect Switch designed to establish an electrical isolation point. It does not replace a circuit breaker for circuit interruption and should be coordinated with the applicable protection and switching equipment.
They refer to different insulation paths within the equipment. The earth/phase condition concerns insulation between energized parts and earth or other phases, while the interruptor gap concerns the dielectric strength maintained across the separated contacts.
It is the specified lightning impulse withstand level across the open contact gap. This parameter is used when evaluating the insulation performance of the isolated section of the switchgear.
Yes. They perform different functions within the switchgear. The circuit breaker provides circuit interruption and protection functions, while the disconnect switch establishes the required isolation. Their operating sequence should follow the switchgear design.
Matching voltage and current ratings does not guarantee mechanical compatibility. Mounting hole arrangements, conductor positions, and available cabinet space may differ between switchgear designs.
No. The value specifies the mechanical operating life of the product. Actual operating frequency depends on the application and switching requirements of the complete electrical installation.
The original 40.5kV Indoor Disconnect Switch model, nameplate, clear photographs, measured mounting dimensions, connection information, and operating arrangement can be provided for technical review.
Address
No. 281, Wei 18th Road, Yueqing Economic Development Zone, Yueqing, Wenzhou, Zhejiang, China
Tel
