Product Overview

KYN28-12 metal-clad, withdrawable medium voltage cubicle switchgear is an indoor electrical apparatus designed for three-phase, 50 Hz single bus section or double bus section systems. It is used for receiving and distributing 3.6–12 kV network power, as well as for controlling, protecting, monitoring, and measuring power circuits.

Product Features

The medium voltage cubicle switchgear is designed in accordance with the standards for metal-clad enclosed switchgear. The complete assembly consists of the cabinet body and the movable parts (i.e., the handcart). The cabinet is divided into four separate compartments. The enclosure has a protection degree of IP4X, while the protection degree for each compartment and the circuit breaker chamber (with the door open) is IP2X.
A complete distribution system is formed through the combination and arrangement of overhead incoming and outgoing lines, cable incoming and outgoing lines, and other functional units. The switchgear can be installed, tested, and maintained from the front. It can also be installed back-to-back to form a double arrangement or placed against a wall, enhancing safety and flexibility while reducing the required floor space.

Shall and Others

The main cabinet of the switchgear is made of imported aluminum-zinc coated steel sheets, processed by CNC machine tools and multiple folding operations. This ensures high precision, excellent resistance to corrosion and oxidation, and a lighter, more robust, and aesthetically refined structure compared with similar products.

The cabinet body adopts an assembled structure using rivet nuts and high-strength bolts, which shortens the production cycle, allows for greater component interchangeability, reduces floor space requirements, and facilitates standardized production and assembly.

product-800-800

Handcart

The frame of the handcart is made of thin steel sheets and is assembled using CNC machining processes. The handcart interfaces precisely with the cabinet's insulation components, and its mechanical interlocking system is safe, reliable, and flexible in operation.

According to different applications, the handcart is classified into circuit breaker, voltage transformer, metering, and isolating types. Handcarts of the same specification are interchangeable. Each handcart has three positions-disconnected, test, and service-inside the cabinet. Each position is equipped with a dedicated positioning device to ensure reliable interlocking and sequential operation.

All handcarts are moved using a screw-and-rod mechanism, making operation simple and flexible for personnel on duty. When removal from the cabinet is required for inspection or maintenance, the handcart can be withdrawn using a dedicated transfer trolley. The trolley is compact in size and, being of a removable type, allows for convenient inspection and maintenance.

Model Description

product-966-701

Medium Voltage Cubicle Technical Parameters

Technical parameters of switchgear

Project		Unit	Parameters
Rated voltage		kV	3.6,7.2,12
Rated frequency		Hz	50
Rated current for circuit breaker		A	630,1250,1600,2000,2500,3150
Rated current for switchgear		A	630,1250,1600,2000,2500,3150
Rated thermal stability current		kA	25,31.5,40,50
Rated dynamic stable current (peak value)		kA	50,63,80,100,130
Rated short circuit breaking current		kA	20,25,31.5,40,50
Rated short-circuit making current (peak value)		kA	50,63,80,100,130
Rated short-circuit making current (peak value)	Power frequency withstand voltage for 1 min	kV	23	32	42
	Power frequency withstand voltage for 1 min	kV	40	60	75
Protection level	The shell is IP4X,and IPZX when doors of compartment and circuit breaker room open.

Technical parameters of circuit breaker

Project	Unit	Parameters
Rated voltage	kV	3.6,7.2,12
Rated voltage	Hz	50
Rated current for circuit breaker	A	630,1250,1600,2000,2500,3150
Rated thermal stability current	kA	20,25,31.5,40,50
Rated dynamic stable current (peak value)	kA	50,63,80,100,130
Rated short circuit breaking current	kA	20,25,315.5,40,50
Rated short-circuit making current (peak value)	kA	50,63,80,100,130
Rated insulation level	Power frequency withstand voltage for 1 min	42
Rated insulation level	Lightning impulse withstand voltage	75
Standard operation		5 Off-0.3s-On-off-180s-On-off
Rated breaking times during short circuit	time	50
Service life		VD4:2000 VS1:10000

Mechanical features of the vacuum breaker

Name	Unit		Value
Clearance between open contacts	mm		11±1
Over stroke			4±0.5
Interphase center distance			210±0.5,250±0.5,275±0.5
Bounce time of contact in switch-on	ms		≤2
Asynchronism of triphase switch-off	ms		≤2
The voltage for switch-off	Max	ms	≤50
	Rated		≤50
	Min		≤60
Switch-on time	ms		≤75
Average switch-on rate	m/s		0.9-1.2
Average switch-off rate	m/s		0.6-0.8
Blocked circuit in various phases	μ Ω		≤40
Contact pressure	N		3200±100

Note：

When controlling 3–10 kV motors, if the circuit breaker's starting current is less than 600 A, a metal zinc-oxide arrester should be installed. The detailed specifications of the arrester shall be determined through consultation between the user and the manufacturer.

When the circuit breaker is used for switching capacitor banks, the rated current of the capacitors shall not exceed 80% of their nominal rated value.

Product usage environment

Ambient temperature: maximum +40 °C, minimum –25 °C
Ambient humidity: daily average not exceeding 95%; monthly average not exceeding 90%
Altitude: not exceeding 1000 m
Seismic resistance: applicable for areas with a seismic intensity of up to 8 he installation site shall have no severe pollution or frequent vibration. Under harsh conditions, the equipment shall be designed to meet Class 1 requirements.
For use in environments differing from those specified in GB3906, the user shall consult with the manufacturer.

Notes:

The heater shall be switched on when the relative humidity exceeds 70%.
For installations at altitudes above 1000 m, the equipment shall comply with the requirements specified in the JB/Z102-71 standard.

Main circuit design

product-800-429

product-800-439

product-800-475

product-800-440

Note: For more wiring options, please download the product brochure.

Application Areas

	Power plant Wind turbine, compressor, pumped hydro storage plant, draft fan, condensate pump, circulating water pump, boiler feedwater pump, etc.
	Oil, Petrochemicals, Natural gas Pipeline transfer pump, injection pump, feedwater pump, submersible oil pump, circulating water pump, brine pump, compressor, booster fan, oil transfer pump, electric submersible pump, etc.
	Coal, Mining Scale removal pump, slurry pump, slag slurry pump, clear water pump, feed pump, axial flow fan, agitation pump, kiln, transmission, dust removal fan, drainage pump, media pump, counter-rotating fan, etc.
	Cement building materials Kiln induced draft fan, kiln forced draft fan, kiln tail fan, kiln head fan, medium-temperature fan, coal mill fan, dust removal fan, circulating fan, raw material grinding fan, cement grinding fan, separator fan, pressure conveying fan, etc.
	Steel and metallurgy Blast furnace blower, induced draft fan, compression fan, air supply fan, feedwater pump, water supply pump, descaling pump, dust removal fan, converter, blast furnace, etc.
	Municipal water supply Aeration blower (for heating, water supply, sewage, etc.), induced draft fan, air supply fan, booster pump, hot water circulation pump, sewage pump, clean water pump, lift pump, water supply pump, reclaimed water pump, etc.
	Light industry, Chemical industry Coal gas blower, booster pump, compressor, axial flow pump, soft water pump, water supply pump, etc.