This project at a UK brewery required the existing 30 year old ACB to be replaced due to unreliability

The contract had been awarded to a major UK switchgear manufacturer who recognised our expertise in this area so they were more than happy to sub-contract it to ExEllison.

The old ACBs had asbestos arc-chutes as is common on many Air Circuit Breakers of this age and is reason enough to change the ACBs as well as the lack of spare parts and expertise to keep them in good working order.

The ExEllison installation team is fully trained for the removal and transportation of Asbestos and provide a traceable disposal certificate for the material removed.

The Customer had originally been told that a week-long shut-down would be required.

However, the unique ExEllison design allows an easy-fitting retrofit assembly to be completely constructed and tested in our works removing the need to make any parts on site.

3 – ACBs were retrofitted and two bus-section ACBs removed and shorting-lings fitted – all in a single day.

ExEllison have retrofitted over 400 ACBs of various types including:

• Ellison
• Ottermil
• ABB, Mitsubishi
• Terasaki
• Siemens
• Reyrolle
• Schneider
• Merlin Gerin
• Johnson Philips
• GEC
• Whipp & Bourne
• STS Switchgear
• Dorman Smith
• Eaton, Proteus
• AF Switchgear

Honeywell are responsible for the operation and maintenance of buildings for blue-chip companies.

The ACB Problem

During routine maintenance of the High Voltage and Low Voltage systems of one of their clients in Birmingham City Centre, ExEllison Switchgear Services discovered a problem with the 11000V isolator close-coupled to the Package Substation transformer.

Whilst the problem was temporarily overcome to ensure that power was returned to the building a solution for the long-term integrity of the supply was required.

The unit in question was of an obsolete design so spares were no longer available. Following consultation with ExEllison Switchgear Services Ltd a solution was devised to meet their specific circumstances.

The ACB Solution

It was agreed that a readily available ACB of standard design be utilised as a replacement for the faulty ACB. With our knowledge of the Ellison equipment we were able to design the interface to enable simple replacement during a single 10 hour shutdown. All of the materials were custom built in advance of the agreed shutdown.

ExEllison Switchgear Services Ltd utilises the latest 3D solid modelling CAD systems to design its products to ensure a first-time fit every time. We have developed standard arrangements for a wide variety of Switchgear retrofits.

In this case a Schneider MV isolator was utilised in conjunction with our custom designed interface.The interface was designed to allow installation into the existing panel with the minimum of modification and down-time. A full assembly kit was supplied with no need for cutting and carving of parts to suit on site.

Only the experience ExEllison have can guarantee a first-time fit without the need for a shutdown in advance of the installation.

CASE STUDY HONEYWELL:

• ACB Replacement Protection replacement,
• Spares
• Switchboard modifications
• Extension Panels
• Emergency response
• Retrofit metering
• Control panels
• Maintenance Installation Services
• Transformer replacement and Substation equipment

Further complications were introduced by the fact that the substation was located on the 7th floor of the building with the lift only reaching the 6th floor.

Specialist lifting equipment was employed to ensure safe movement of the 300Kg isolator.

Specialist High Voltage Engineers ensured the correct termination of the 11kV cabling followed by thorough testing of the modified system before re-energisation.

The ACB Problem

Any failure of supply would have serious consequences not only to the shops within the centre but the data-centres that a number of their clients employ.

The main LV switchboard was some 20 years old and utilised Ellison GEA air circuit breakers

Whilst the ACBs had given years of good service they had encountered a number of problems with difficulty in closing and failure of the CPR Overcurrent relay fitted.There were also considerations made as to the problems in the supply of spare components in the event of future problems.

There were also considerations made as to the problems in the supply of spare components in the event of future problems.

The ACB Solution

Following consultation with ExEllison Switchgear Services Ltd we embarked on a programme of replacing the ACBs with a modern units including integral protection units.

ExEllison Switchgear Services Ltd utilises the latest 3D solid modelling CAD systems to design its products to ensure a first-time fit every time. We have developed standard arrangements for a wide variety of ACB replacements.In this case Mitsubishi ACBs were utilised. The interface was designed to allow installation into the existing panel with the minimum of modification and down-time.

A full assembly kit was supplied with no need for cutting and carving of parts to suit on site. Only the experience ExEllison have can guarantee a first-time fit without the need for a shutdown in advance of the installation.

Note that ExEllison Switchgear Services Ltd does not install an Air Circuit Breaker into an existing ACB chassis. There is little point in replacing an ACB whilst still relying on aged contact finger clusters. We take the old ACB out completely right back to the basic connections. This weak point is removed to ensure the integrity of the new assembly.

Typically the removal of 2 incoming ACBS and a bus-section ACB and the installation of new replacement ACBs is completed within an 8-hour shutdown. In this case the three main ACBs were replaced in a planned 12-hour shutdown—with 3 hours to spare. The opportunity was taken to upgrade the metering by fitting multi-function metering integrally to the new modules.

ExEllison’s unique design ensures perfect alignment of copperwork with no cutting on site. CTs can be fitted within the new module to supply the new metering. Fuse fed voltage references are also encorporated.

Internal shrouding is fitted to make the ACB module complete. A fully shuttered Cassette is used to ensure the operators safety
The installation is completed and the equipment returned to service following ACB testing. The equipment is now suitable for continued use at a fraction of the cost of a replacement switchboard and all of the associated civil and cabling works.

ExEllison’s unique design ensures perfect alignment of copperwork with no cutting on site. CTs can be fitted within the new module to supply the new metering. Fuse fed voltage references are also encorporated.

Internal shrouding is fitted to make the Air Circuit Breaker module complete. A fully shuttered Cassette is used to ensure the operators safety.

The installation is completed and the equipment returned to service following ACB testing. The equipment is now suitable for continued use at a fraction of the cost of a replacement switchboard and all of the associated civil and cabling works.

For Further information on ACB replacements or our other services contact us at enquiries@exellison.co.uk or Tel 01902 632639. Mob 07786 350764, 07973 563855.

The ACB Problem

Typically a 24- hours a day, 7-days a week operation they require unquestioned continuity of supply. Any such business must keep any interruption to supply to an absolute minimum—even if planned.

The main package substation was some 15 years old.

Installation of a new production facility demanded increased capacity resulting in the need for:

• Transformer upgrade.
• ACB Protection replacement.
• Addition of fuse-switch outgoing circuits.
• Overhead busbar trunking.