Model and Its Definition

Note: If the earthing switch is not equipped, the earthing operating shaft shall serve as an interlock shaft, with the overall dimensions remaining unchanged.
Service Environment Conditions
◆ Ambient temperature: -25℃ ~ +40℃
◆ Relative humidity: Daily average ＜ 95%, monthly average ＜ 90%
◆ Altitude: Not higher than 1000 m
◆ Seismic intensity: Not exceeding Grade 8
◆ Service location: Free from explosion hazards, chemical corrosion, severe vibration and pollution
◆ Service conditions for altitude above 1000 m
◆ When the altitude exceeds 1000 m, the air density will decrease relatively, which will affect the protection parameters of electrical equipment.
◆ The user must conduct relevant calculations when selecting the switch.
◆ Recommended calculation method:
Determine the altitude H of the designated location, calculate the corresponding altitude correction factor Ka in accordance with the provisions of GB 311.1 (refer to Formula 1). Multiply the lightning impulse withstand voltage and power frequency withstand voltage of the switch by Ka; the resulting values are the withstand voltage parameters that the switch must meet when operating at the high altitude H and also when used in environments below 1000 m.

Applicable Cabinet Types
It can be assembled in small-sized fixed cabinets, ring main units or packaged substations.
The main circuit of the DHZN-12GD series indoor high-voltage three-position vacuum circuit breaker is arranged vertically: the isolating switch is located at the upper part, the vacuum circuit breaker in the middle, and the earthing switch at the lower part. The operating mechanism, circuit breaker mechanism and interlocking mechanism are positioned at the front of the switch. This switch is suitable for inverted installation.
Safe and High-performance Solid-sealed Poles
High reliability, stable insulation performance, more robust structure, miniaturization, maintenance-free operation, enhanced environmental friendliness, and high mechanical resistance.
Visible Isolation Break Point
Rotary isolating switch with visible break points after opening.
Modular Operating Mechanism
The circuit breaker adopts a modular operating mechanism, which allows independent replacement or maintenance and features excellent interchangeability. It can be operated manually, or alternatively equipped with AC/DC energy storage operation to achieve remote control.
Three-axis Stepwise Operation, Reliable Mechanical Interlocking
The isolating switch, circuit breaker and earthing switch are operated by separate individual shafts. Forced mechanical interlocks are provided between the three shafts to prevent misoperation.
Non-contact live display sensors are equipped at the outlet terminals.
No capacitors, adopting non-contact induction technology, safe and reliable!
A reliable interlock structure is designed between the cabinet door and the connecting switch.
Ensure the operator's safety with an adjustment-free cabinet door locking device.
Technical Parameters

Item	Unit	Parameters
Rated Voltage	kV	12
(1 min) Rated short-time power-frequency withstand voltage: Phase-to-phase / Fracture		42/48
Rated lightning impulse withstand voltage (peak value): Phase-to-phase / Fracture		75/85
Power-frequency withstand voltage of secondary circuit (1 min)	V	2000
Rated Frequency	Hz	50
Rated Current	A	630 1250
Rated Short-Circuit Breaking Current	kA	20	25	31.5
Rated Peak Withstand Current	kA	50	63	80
Rated Short-Circuit Making Current	kA	50	63	80
4s Rated Short-Time Withstand Current	kA	20	25	31.5
Duration of Rated Short-Time Withstand Current	s	4
Rated Breaking Current for Single / Back-to-Back Capacitor Banks	A	630/400
Rated Capacitor Bank Closing Inrush Current	kA	12.5 (frequency not exceeding 1000 Hz)
Rated Short-Circuit Current Breaking Times	Times	30
Mechanical Service Life (Isolator 1 / Circuit Breaker / Earthing Switch)		3000/10000/3000
Allowable Cumulative Wear Thickness of Moving and Static Contacts	mm	3
Rated Common Operating Voltage	V	MC24/48/110/220 DC24/48/110/220
Rated Opening Operating Voltage
Rated Voltage of Energy Storage Motor	V	MC24/48/110/220 DC24/48/110/220
Rated Power of Energy Storage Motor	V	70
Energy Storage Time	s	≤ 15
Contact Opening Distance	mm	9 ± 1
Overshoot Travel		3.5 ± 0.5
Contact Closing Bounce Time	ms	≤ 2
Three-Phase Opening/Closing Asynchronism		≤ 2
Opening Time (Rated Voltage)		≤ 40
Closing Time (Rated Voltage)		≤ 60
Average Opening Velocity (at Initial Contact Separation, 6 mm)	m/s	0.9 ~ 1.3
Average Closing Velocity (6 mm ~ Initial Contact Making)		0.5 ~ 1.1
Contact Opening Rebound Amplitude	m	≤ 2
Contact Closing Contact Pressure	N	2400±200 ( 20 -25kA ) 3100+200 ( 31. 5kA )
Rated Operating Sequence		0-0.3s-CO-180s-CO

Configuration
Standard Configuration: Wired in accordance with the standard wiring schematic diagram, equipped with an anti-tripping device. Without a closing locking device, an overcurrent device, or an undervoltage device.

Configuration	Parameters	Remarks
Energy Storage Motor	75W	Standard Configuration
Closing Coil	A(D)C24~220V	Standard Configuration
Opening Coil	A(D)C24~220V	Standard Configuration
Disconnector Auxiliary Switch	1 NO + 1 NC, 5A	Standard Configuration
Earthing Switch Auxiliary Switch	1 NO + 1 NC, 5A	Standard Configuration
Energy Storage Mechanism Auxiliary Switch	2 NO + 1 NC, 5A	Standard Configuration
Circuit Breaker Auxiliary Switch	8 NO + 8 NC, 5A	Standard Configuration
Anti-tripping Device	A(D)C24~220V	Standard Configuration
Live Sensor (Inductive Type)	Non-contact Type	Standard Configuration
Locking Device	A(D)C24~220V	Optional Configuration
Overcurrent Release	3.5A、5A	Optional Configuration
Undervoltage Device	A(D)C24~220V	Standard Configuration

Referring to the switch operation indicator plate on the right, the instructions are as follows:
Double Interlock: For the circuit breaker, disconnector and earthing switch, a forced mechanical interlock is configured for operation. An anti-misoperation locking device is designed for the circuit breaker, disconnector and earthing switch to prevent incorrect operation.The disconnector and earthing switch are operated step by step via separate independent shafts respectively, and a forced mechanical interlock is installed between the two operating shafts. After opening and closing operations of the switches, please confirm their respective open/closed states through the observation window.
Interlock Between Circuit Breaker, Disconnector, Earthing Switch and Cabinet Door
◆  The disconnector and the earthing switch are equipped with a mutual forced mechanical interlock, which allows only one of the two devices to be closed and prohibits their simultaneous closing.
◆  The disconnector can only be closed after the earthing switch is opened; the earthing switch cannot be closed after the disconnector is closed.
◆  The circuit breaker can be closed only when the closing lock is in the locked position, while the disconnector and earthing switch are not operable under this condition.
◆  The circuit breaker cannot be closed when the closing lock is in the unlocked position, whereas the disconnector and earthing switch become operable.
◆  After the circuit breaker is closed, the closing lock cannot be unlocked, and the disconnector as well as the earthing switch are not operable.
◆  The cabinet door can only be opened after the earthing switch is closed.
◆  The earthing switch can only be opened after the cabinet door is closed.


Operation of Closing Lock
1、Locking
Rotate the outer ring of the locking operation shaft by 90° (to release positioning), push it to the limit position in the locking direction, and then rotate the outer ring of the operation shaft by 90° again (to lock positioning).
2、Unlocking
Rotate the outer ring of the locking operation shaft by 90° (to release positioning), push it to the limit position in the unlocking direction, and then rotate the outer ring of the operation shaft by 90° again (to lock positioning).
Operation of the Circuit Breaker
Manual Operation
1、Use the dedicated energy storage handle for energy storage.
2、Closing: Press the closing button. (If equipped with a closing lock or undervoltage device, the secondary circuit must be powered on before closing can be performed)
3、Opening: Press the opening button.
Electric Operation
1、After the secondary circuit is powered on, the energy storage mechanism will store energy automatically.
2、Closing: Press the closing button in the control circuit.
3、Opening: Press the opening button in the control circuit.
Operation of the Disconnector
Clockwise rotation is for disconnector opening.
Counterclockwise rotation is for disconnector closing.
Operation of Cabinet Door Locking
Closing the cabinet door automatically releases the interlock between the cabinet door and the earthing switch. After the earthing switch is closed, if the cabinet door is opened, the earthing switch will be automatically locked and cannot be operated.