GNF38-12/630A type indoor ring main unit isolation switchDetailed product description：

The LZFW-35GY current transformer adopts our company's unique technology, which integrates outdoor epoxy resin and silicone rubber into a composite insulation form. It is not a general form of silicone rubber umbrella sheet bonding, and the overall product is firm. It belongs to the new generation of outdoor products. Widely used in outdoor or indoor power systems with a rated frequency of 50 Hz and a rated voltage of 35 kV or below, it is also used for metering, measurement, and monitoring protection.

Characteristics of GNF38-12/630A indoor ring main unit isolation switch
1. This product is made of outdoor epoxy resin, and the non winding part is coated with silicone rubber and fully vacuum cast. It is a fully enclosed insulation and pillar structure. The product fully combines the advantages of good processability and strong heat dissipation performance of outdoor epoxy resin with the strong UV resistance, good water addition, anti fog flash and anti pollution flash ability of silicone rubber, while complementing each other's shortcomings, to achieve good internal and external insulation performance. The product has anti fog and anti humidity, anti pollution flash, excellent resistance to cold and hot shock, good environmental adaptability, strong hydrophobicity and anti UV linear ability, anti-aging and arc resistance, long service life, and can fully meet outdoor use conditions.
2. The product adopts a ring-shaped ultra microcrystalline alloy iron core and imported high-quality silicon steel sheet coil iron core. Has high metrological accuracy, stable error, and low instrument security factor; Stable protection level performance and high accuracy limit coefficient. The transformer has the characteristics of low power consumption and minimal residual magnetism.
3. According to user requirements, production can be done in various ratios and multi-level combinations. Beneficial for power station expansion and effectively saving investment.
4. The product can be installed independently or used in conjunction with outdoor circuit breakers and other outdoor equipment. It has the characteristics of easy installation and replacement, and maintenance free use.

Usage conditions for GNF38-12/630A indoor ring main unit isolation switch
Fully meet the high-altitude outdoor product usage conditions specified in IEC185-87 and GB1208-1997, as well as the requirements of Level II pollution prevention level.

Basic technical parameters of GNF38-12/630A indoor ring main unit isolation switch
1. Rated voltage 35 kV
2. Rated altitude ≤ 4000 meters
3. Rated insulation level 40.5/95/185 kV
4. Rated primary current 20-3000 A
5. Rated secondary current 5A or 1A
6. Partial discharge capacity in accordance with GB1208-1997 standard, apparent discharge capacity ≤ 20 pC
7. Dynamic thermal stability current: 1 second thermal current=110 I1n; Dynamic stability current=2.5 Ith
8. Rated primary current, level combination, and corresponding rated output relationship Rated primary current

Overview

The GNF38-12KV series indoor ring main unit isolation switch is designed and manufactured to meet the needs of the development of fixed high-voltage cabinets and ring main units towards compactness and miniaturization. It has a three station structure and a fully insulated bottom plate; And equipped with coaxial locking and a complete mechanical interlocking mechanism, the appearance is compact and small. It is the best optional switch for compact box type switchgear.

Switch model and meaning



Reference standards

GB1985-1989 AC High Voltage Disconnectors and Grounding Switches
IEC129-84 AC isolating switches and grounding switches

Normal usage conditions

a. Surrounding air temperature: upper limit+40 ℃ lower limit -25 ℃
b. Altitude not exceeding 2000m
c. Relative humidity: daily average not exceeding 95%, monthly average not exceeding 90%
d. The surrounding air should not be significantly polluted by corrosive or flammable gases, water vapor, etc
e. No frequent severe vibrations

Main technology of GNF38-12/630A indoor ring main unit isolation switch

Main structural features

Adopting busbar through wall integral insulation bottom plate (APG process), the external insulation creepage distance can reach 24MM/kV, and the insulation performance is good.
The single break point and three station structure ensure that the isolation switch cannot be grounded when closed and cannot be closed when grounded.
Equipped with coaxial manual operation mechanism and position positioning device.

Installation and debugging

After opening the box, the product should be checked for any damage or rust, the product nameplate and certificate of conformity should match the purchase order, and the packing list should match the actual product and be in good condition.
Clean the surface of dust and dirt.
Check if the screws at the main connecting parts of the switch are loose. If so, tighten and adjust them.
Apply industrial Vaseline oil to the mechanical friction parts.
According to the position of the high-voltage cabinet and the ring main unit, installation is required, and attention should be paid to the insulation distance between the live part and the ground when the switch is opened, which should be greater than 125cm.
After the switch is installed, it should be operated without load 3-5 times, and the opening, closing, and grounding signs should be checked to ensure that they match the corresponding operation. There should be no abnormal phenomena such as jamming during operation.
The pressure of the contact spring between the moving and stationary contacts has been adjusted before leaving the factory, and users do not need to adjust it again.
The connection between the switch and the busbar must have good contact and be securely fixed.

Usage and Maintenance

The opening, closing, and grounding positions of the switch are determined and locked, and the mechanical interlocking action is performed. The identification of each position is completed by the operating mechanism.
Before operation, it is necessary to check whether the mechanism is safe and reliable.
First, turn the wrench on the panel towards the operating axis, then release it. Insert the handle and rotate it in the direction indicated by the arrow on the panel. Once the operation is in place, the wrench on the panel will automatically return to its original position. Repeat the above steps when operating again.
When the operating mechanism leaves the factory, its internal sliding parts are coated with lubricating grease. If the user finds any obstruction during operation, they can open the front cover and apply lubricating grease to the sliding parts.
The maintenance of the switch is not carried out with electricity, and it is not allowed to pull the switch with load.
During maintenance, the fixing screws of the insulation base and insulation support, the spring compression of the moving contact knife, the shaft retaining ring on the connecting pin between the insulation rod and the insulation crank arm, and the opening on the connecting pin between the insulation rod and the moving contact knife should be carefully inspected. If there are any abnormalities, they should be adjusted and maintained in a timely manner.
When the contact positions of the static contact and the moving contact blade are found to be burnt or blackened during maintenance, it is not allowed to use a file to lower the contact points. Only sandpaper can be used to polish them, and then industrial Vaseline grease can be applied.
During maintenance, attention should be paid to observing the deformation of the clamping spring of the moving contact blade. If there is any deformation, it should be adjusted or replaced in a timely manner.

Appearance and installation dimensions

Installation method

GNF38-12/630A type indoor ring main unit isolation switch

Rated primary current （A）	Accurate level combination	Rated secondary output (VA)
		0.2（0.2S）	zero point five	10P10	10P20
20~600	0.2（0.2S）/10P	fifteen	---	fifty	twenty-five
	0.5/10P	---	twenty-five
	10P/10P	---	---
	0.2 (or 0.2S)/0.5/10P	fifteen	twenty-five	forty	twenty
	0.2 (or 0.2S)/10P/10P