DCML: High-current DC Disconnector for Off-load Isolation

The DCML is G Corner's high-current DC disconnector for off-load isolation in demanding industrial environments. Incorporating a patented drive system and silver plated copper contacts, it provides operators with a reliable, low-maintenance means of isolating circuits safely before maintenance or system work begins.

Product Description

The DCML is a compact, modular high-current DC disconnector rated from 6 kA to 72 kA at up to 1,500 Vdc. It is designed for off-load operation - providing safe and reliable isolation of a circuit when opened. Unlike DC switches, disconnectors are not designed to make or break circuits under load. The DCML should be operated only when the circuit has been de-energised, ensuring operators can carry out maintenance with full confidence in the isolation provided.

The DCML uses air as its contact insulation medium, with hermetically sealed contacts and silver plated copper contact faces for durability and low contact resistance over an extended service life. The product incorporates a patented drive system, a distinguishing feature of the DCML range. Actuation is available in both pneumatic and electric configurations as standard, with operation times of under 45 seconds, and faster 1 second and 10 second options also available.

The DCML supports both horizontal and vertical mounting orientations and is suitable for installation in rectifier rooms, tank houses, and exposed process environments. Its compact, self-supporting modular design makes it well suited to new installations and retrofit applications alike.

All G Corner products are engineered to the specific requirements of each application. The DCML represents what we can achieve for high-current off-load DC isolation - the exact configuration, current rating, and options will be developed with you to suit your installation.

Features

The following features are standard to the DCML

Compact design
Cost-effective modular design
Low voltage drop
Low maintenance
Self-supporting design
Connect to Al or Cu busbars
High deformability tolerance

72 kAs

Maximum Current Rating

10 kVp

Impulse voltage withstand - open position

4 L

Environmental Protection (IEC 60947-3)

Switching between circuits or cell groups under off-load conditions, allowing sections of the system to be isolated and reconfigured safely. The DCML provides a clearly defined isolation point for each circuit position, supporting controlled switching operations during planned outages or system changeovers.

Providing safe and reliable isolation of a circuit or section of plant before maintenance work begins. The DCML allows operators to isolate specific parts of the system without affecting the wider installation, supporting efficient planned maintenance programmes and minimising overall system downtime.

Primary Installation Environment

Rectifier Room

The DCML is suited to installation in rectifier rooms where DC circuits from transformer rectifier units require reliable isolation points for maintenance and switching operations.

Primary Installation Environment

Tank House

Where the DCML is installed within or adjacent to the tank house environment, it is designed to withstand the corrosive atmospheres, high humidity, and continuous high-current conditions characteristic of electrowinning and electro-refining operations.

Primary Installation Environment

Exposed Process Environment

The DCML can be installed in exposed process environments where it may be subject to outdoor conditions or industrial atmospheres. Environmental protection to IEC 60947-3:2020 Level 4 is provided as standard.

The DCML can be configured with a range of options to suit specific installation and operational requirements. These are discussed and agreed during the engineering process for each project.

As with all our products displayed online, this example high-current DC switch is an illustration of a fully customisable product that will be tailored to individual business requirements.

Pre Contact – Charge Clearing contact available (<10A)

Pneumatic actuation option

RTD temperature monitoring

Inductive Limit switches

Operational / mechanical counter

Padlocking

Manual interlocking

Drip cover

Control panel

Torque limiter

Blocking magnets

Alternative current ratings (on request)

01/ Product Classification

Product Classification Product Data

Product name	DCML
Category (L2)	DC Disconnectors
Product code / SKU root	DCML-X….
Product type	Disconnector
Applicable standard(s)	IEC 60947-3:2020
Device family description	High Current DC Disconnectors
Primary installation environment	Rectifier room / tank house / exposed process

Electrical Ratings Product Data

Rated voltage (Vdc)	1500
Rated current — min (kA)	6
Rated current — max (kA)	72
Rated current options (kA)	6, 12, 18, 24, 30, 36, 48, 60,72
Alternative current ratings available	Yes
Short circuit withstand — 1s	≤10 × rated current
Voltage drop at rated current	<50 mV
Temperature rise at rated current	<65 °K
Utilisation category	DC-20A

Dielectric Performance Product Data

Impulse voltage withstand — open position (kVp)	10 kVp
Withstand voltage — live parts to earth, 50 Hz 1 min	5 kV
Withstand voltage — open contacts, 50 Hz 1 min	5kV
Withstand voltage — open contacts, dc	3,820 V
Withstand voltage — aux contacts to earth, 50 Hz 1 min	2.5 kV
Withstand voltage — actuator / motor to earth, 50 Hz 1 min	2 kV

Construction Product Data

Contact Insulation Medium	Air
Frame / drive material	Stainless steel 316, FRP & GRP insulation components
Terminal / blade / finger material	High conductivity copper
Contact face material	Silver Plated Copper
Busbar plate material	Copper
Busbar connection method	Bolted joint
Hermetically sealed contacts	Yes
Isolation gap visibility	Enclosed
Patented drive system	Yes
Mounting orientation	Horizontal or Vertical

Environmental Product Data

Standard degree of protection	IP0
Standard environmental protection level (IEC 60947-3)	Level 4
Ambient temperature range	-5°C to +50°C
Relative humidity	≤95%
Installation altitude	≤1000 m