A steel company in South Wales undertook a large construction project to rebuild their Blast Furnace in 2012. As part of the project, Iconsys was tasked with replacing the transformer, drives, motors, and control systems for the combustion air fans, cooling tower fans, and fume extraction fans. The objectives were to install new low harmonic variable speed drives for energy efficiency and cost savings. For the combustion air fans, 3 variable speed drives were installed to control 3 fans. For the cooling tower fans, 3 variable speed drives were installed to control fan speed and maintain water temperature. For the fume extraction fans, 2 existing variable speed drive systems were replaced with new drives and motors.

1. Case Study
PASSIONATE ABOUT ENGINEERING
BF4 Rebuild VSD’s
Iconsys, Iconsys House, Hortonwood 33, Telford, TF1 7EX, UK
T +44 (0)1952 607300 F +44 (0)1952 607333 info@iconsys.co.uk www.iconsys.co.uk
PROJECT OVERVIEW
A steel company in South Wales have undertaken the largest
construction project in the UK for 2012. The Rebuild of their Blast
Furnace is of critical importance to the business.
Part of this project is the design, manufacture, supply, installation
and commissioning of the Transformer, Drives, Motors and Controls
Systems for the:
Combustion Air Fans
Cooling Tower Fans
Fume Extraction Fans
PROJECT OBJECTIVES
To replace the existing Direct On Line Motor Starters with state
of the art low Harmonic Variable Speed Drives along with new
transformers and motors.
These Variable Speed Control of the Fans will provide costs savings
and energy efficiency that will be beneficial both financially and
environmentally.
PROJECT SOLUTION
Stoves Combustion Air Fans
This system comprises of 3 variable speed drives, the speed
of which will be determined by duty cycle and combustion
air demand.
The fans operate as two duty and one standby although they can
operate together at a reduced speed. The control and speed set
point(s) are be derived from an ABB AC800 PLC over a ProfiBus
DP link.
Each Combustion Air Fan System consist of:
3,300V/690V Supply Transformers
600kW ACS800 Low Harmonic Variable Speed Drives
Local operator stations at the drive, transformer & motor
Cooling Tower Fans
The existing fixed speed motor control systems for the water
cooling towers are upgraded with 3 new variable speed drives each
rated at 90KW.
The speed and number of fans driven vary to maintain the
set delivery water temperature.
The control and speed set point(s) are derived from an
ABB AC800 PLC over a Profibus DP link.
The Form 4 MCC consists of:
3 off ACS800 Low Harmonic 90KW VSD’s and 5 switch 3P+N
switch fuse supplies
Local operator stations located at each motor
The above is housed in a specialised IP54 steel container
designed specifically for this application
Fume Extraction Fans
The two Fume Extract Fans are currently driven by “Syncdrive”
variable speed drive systems. These are replaced by new drives and
motors.
The existing motor(s) were replaced with new motors inclusive
of a new bed plate and half coupling.
The control and speed set point(s) for the new ACS800 Drives
are derived from an ABB AC800 PLC over a ProfiBus DP link.
Each of the two systems consists of:
11,000V/690V Supply Transformers
2.7MW ACS800 Variable Speed Drives
2.7MW Motor including bedplate, coupling and guard
Local operator stations
The drives will be housed in a specialised IP54 steel
container designed specifically for this application to
include internal ducting which will remove in excess
of 50kW of dissipated heat from the Drive.
It is believed these Drives are the largest low voltage air cooled
Variable Speed Drives in the UK.
CS0018