MODIS ULTRA Main Board System

Main Distribution Boards

Main Distribution Switchboards


Main Distribution Boards

The Main Power Distribution Board range named Modis Ultra, is a fully Type Tested/Design Verified Assembly to the latest BS EN 61439 tested for operation at 500C ambient

It is a Floor Mounting and Free Standing system available in sheet steel cubicles of Forms 2 to 4 with current ratings up to 6300A and fault rating of 50kA for 1 second/3 seconds or 80kA for 1 second and 100kA for 1 second.

Technical Specification:

  • Type Tested / Verified Assembly to the latest standard IEC 61439 and certified by ASTA
  • Ratings up to 6300A
  • Fault Ratings of 50kA for 1 second / 3 secs, 80kA for 1 second and 100kA for 1 second
  • Tested for operation at ambient temperatures of 50°C
  • Frames formed from 2.5mm sheet steel, 3.0mm available on request
  • Doors & Covers fabricated from 1.6mm sheet steel, 2.0mm available on request
  • Form of segregation up to Form 4 Type 6, Type 7 available on request
  • Busbars from HDHC Tin Plated Copper
  • Standard rating of IP43, IP54 available on request
  • Sheet steel epoxy powder coated to light grey semi-gloss as per RAL 7035 with an average 65 microns paint thickness
  • Enclosure sections available in widths of 600mm, 800mm & 1000mm, depths of 800mm or 1000mm and a height of 2300mm including an integral plinth


  • Switchboard EN 61439-2
  • ACBs EN 60947-2
  • MCCBs EN 60947-2
  • MCBs EN 60898
  • RCBOs EN 61009
  • RCCBs EN 61008
  • Fuse Switch EN 60947-3


The Modis Ultra busbar system is 4-pole with a fully rated neutral available in 1250A, 1600A, 2500A and 3200A. ASTA certified busbars have a fault withstand rating of 50kA for 3 seconds.


The Modis Ultra system is designed with Form 4a Type 2 or Form 4b Type 6 separation as standard with front or rear cabling access options. Type 7 separation is available upon request.


Three different frame widths and two different frame depth options available. All frames have a standard height for modular design.

Ingress Protection:

The Modis Ultra system has a standard rating of IP43 with IP54 option available upon request.

MODIS ULTRA Type Tested Main Distribution Board


The busbar systems are four-pole with a fully rated neutral and are available in 1250A, 1600A, 2500A and 3200A options.

All systems are tested for temperature rise and short circuit withstand:

  • 1250A tested at 50kA for 3s
  • 1600A tested at 50kA for 3s
  • 2500A tested at 50kA for 3s
  • 3200A tested at 50kA for 3s

The busbars are manufactured from HDHC tin plated copper and are mounted on a patented, insulated and reinforced support. All connections to the busbar are clamped with no drilling required. This makes the busbar system easy to connect saving time during build and installation. Busbars can be mounted at the top or bottom of each frame depending on the required cable entry point.

Busbar cross-sectional area:

Designation Current rating (A) No. of Laminations Size(W x D mm) mm²
Modis Ultra 1250A 2 30 X 10 600
Modis Ultra 1600A 2 50 X 10 1000
Modis Ultra 2500A 2 100 X 10 2000
Modis Ultra 3200A 2 150 X 10 3000


The Modis Ultra system houses all devices and busbars within rigid welded or bolted frames. Frames are available in 400, 600 and 800mm widths, 800 or 1000mm depths and a standard height of 2300mm.

The Modis Ultra system is designed for installation in enclosed locations where space is a premium. The standard cubicles are IP43 with the option to upgrade to IP54 if required. The frames are painted in light grey RAL 7035 epoxy polyester film.

Protective Earth Conductors:

Modis Ultra switchboard is fitted with a horizontal earth conductor mounted either at the top or the bottom of the frame depending on the cable entry. The conductor runs the full length of the system and is sized according to the fault withstand of the busbar system.

Pre-punched holes in the conductor allow quick and reliable connections and thereby reducing the installation time whilst maintaining a high level of confidence in the integrity of the joints.


The Modis Ultra switchboard offers good all-round access and has the option of front or rear access for cabling. Removable gland plates make cable glanding quick and safe. Removable barriers simplify cable connection and termination for outgoing devices.

Internal Segregation:

The Modis Ultra system has been designed to exceed the requirements of EN 61439-2 with regard to providing Form 4a Type 2 or Form 4b Type 6 separation options. The system is designed for front and rear access and has an IP43 protection as standard.


The Modis Ultra switchboards accommodate the Dorman Smith range of withdrawable Air Circuit Breakers up to 3200A in TP & N or 4-pole versions as the standard option for incoming device. The outgoing devices can be either fixed or plug-in MCCBs in TP & N or 4-pole up to 800A. All devices are installed with door-interlocking handles for operational safety. The busbar system has been tested to the breaking capacity of the devices ensuring correct fault withstand protection at all levels of the installation.


The new Loadline R range of air circuit breakers utilise leading-edge technology and feature a number of innovations which makes this family of products ideal as the incoming device in the Modis Ultra system. All devices comply with EN 60947-2 standard and are available in three different frame sizes and with current ratings of 630A to 6300A. ACBs are available as three or four-pole, fixed or withdrawable and have a range of accessories from simple key locks to intelligent trip units with data measuring and communication facilities.

Fuse Combination Units

The Loadswitch fuse combination units have been designed to meet customer needs for straight forward installation, ease of cabling connection and exceeding the EN 60947-3 standard. The full uninterrupted duty ensures that these units will maintain full rated load indefinitely. With category of AC23A and short-circuit capacity of 80kA, the Loadswitch fuse combination units can be installed with confidence on any inductive or resistive load.


The Loadline range of MCCBs are available in current ratings from 20A to 1600A and have an extensive range of complementary accessories. All devices comply with EN 60947-2 standard and are available in thermal/magnetic and electronic varieties. Electronic MCCBs are category B for utilisation selectivity.


The Dorman Smith Loadcentre range of MCBs provide you with the option of B,C or D characteristic breakers from 6A to 63A. These MCBs are available in one to four-pole options and have a range of complementary RCBOs and RCCBs to meet your specific requirements. The Loadcentre range is the premier choice for final circuit protection within the Modis Ultra switchboard system.

Digital Metering Systems

The Modis Ultra switchboard system can accept a comprehensive range of fully programmable, highly accurate multi-function digital metering systems for all power monitoring applications. The digital meters can measure, clearly display and communicate true RMS values, power quality data and total harmonic distortion of the installation. To meet specific user requirements we offer a variety of communication output options, case styles and LED or LCD displays.

Kilowatt Hour Energy Meters

A range of panel mounted and DIN-rail mounted meters are available for monitoring energy consumption. Self-contained meters offer combined kWh or kVArh energy measurement with pulsed or analogue output options and selectable CT and VT ratios. This style replaces the rotating disc meters and separate instantaneous watt meters.

Protector Trip Relays

This range of devices includes electronic control products for the continuous monitoring of many electrical parameters and the protection of the associated circuits. Designed to fit a wide variety of applications, this range offers both technologically advanced and traditional products. Included within the portfolio are multi-functional microprocessor based systems and single parameter units for measuring earth leakage, ground fault current, vector shift and rate of change of frequency (ROCOF).

Meter Relays and Digital Indicators

Dorman Smith provides a range of meter relays and digital indicators for measuring, monitoring and control of a variety of electrical and process parameters. Meter relays are ideal for process control and load-shedding applications, combining an indicator with set points which operate alarm and control circuits when the signal deviates from the set limits. This range includes digital and analogue meter relays, digital bar graph indicators and controllers. These instruments have been specifically designed for use in control panels and switchboards, monitoring systems, power generation and control applications.

Analogue Instruments

High quality analogue instruments designed to measure an extensive range of electrical and electronic parameters are often the preferred choice for panel instrumentation. These instruments are precision engineered and are robust, ensuring accurate measurement and display in the most demanding environments. The Dorman Smith range offers various styles, sizes and specifications to meet the exacting needs of industrial installations.

Modular Distribution Surge Protectors

The Modis Ultra system supports several forms of TVSS, including modular distribution surge protection for single and three-phase power systems. Dorman Smith can offer TVSS with high surge handling capabilities of 90, 150 and 300kA, which are intended for high lightning exposure areas and for the protection of critical systems where long life and low maintenance are important factors. Type I and type II units available to meet different surge supression requirements.

Distribution Surge Protector

A series of general purpose, hard-wired, single and three-phase distribution surge protectors with 30kA of surge capacity, a two stage (redundant) protection and pre-failure indication are available. Some models are available with relay contacts that enable remote monitoring of the phase protection status.

Sub-Panel Protectors

The compact, 10kA rated, 6651C Protector has been designed for sub-distribution panels that supply critical hardware items; such as computers, PABX systems, network file servers and mainframes. This hard-wired surge suppression device is hard-wired and has redundant protection and offers full status monitoring in single and three-phase systems.