ABB Compact control system replaces PLC AC700F

ABB Compact control system replaces PLC AC700F

The AC 700F controller increases the scalability of the

compact control system Freelance 800F towards very

small applications with only a few I/Os and closes the

gap between PLCs (programmable logic controllers)

and complex process control systems. It is suitable

for smallest applications with about 10 to 250 I/Os per

controller and thus opens up additional application areas

for the Freelance 800F control system, which is suitable

for both small and also medium-sized projects with several

thousand signals. Comfortable, advanced functions

of control systems are now also available for very small

applications – and all at a very reasonable price. The

AC 700F controller offers a large number of advantages

compared to a standard PLC with visualization from thirdparty

vendors. The projects on the following pages show

these advantages and the various application areas for

the AC 700F controller.

Thanks to the compact control system Freelance 800F and its

AC 700F controller it is now possible for smaller automation

solutions, which to date have been dominated by PLCs, to

benefit from the advantages of process control systems,

particularly in the process industry. There is a wide range of

use in many industries including chemicals, petrochemicals,

oil and gas, metals, cement production, glass production, etc.

The AC 700F controller can be integrated into existing Freelance

800F systems in the same way as the AC 800F controller.

In contrast to PLCs, the AC 700F controller offers all of the

advantages of the compact control system. Important for

engineering and maintenance: A single engineering tool for

all tasks: Control Builder F.

DigiVis, the visualization tool, makes operation easy, structured

and intuitive. Pre-engineered components such as faceplates,

module diagnostics, event lists, the alarm line, trend displays

and automatically generated SFC (Sequential Function Chart)

displays play a key role in this regard. The use of predefined,

field proven libraries including faceplates significantly eases

the transparency, readability and adaptability of the application

and substantially increases security. The advanced diagnostic

options and improved alarm handling allows cost cutting in

the operation and maintenance phase and asset availability

can be enhanced. This substantially increases the economic

efficiency of the entire plant.

AlzChem GmbH in Trostberg, a subsidiary of Evonik Industries

AG, produces specialty chemicals products with a wide range

of uses. These chemicals are used, for example, in the production

of crop protection products, pigments, dyes, pharmaceuticals

and polymers.

In the past, an inverted filter centrifuge in a system for extracting

natural substances was PLC-controlled at AlzChem GmbH.

The program code for the PLC, a standard program from the

manufacturer, was not transparent and needed specialists to

make changes. The program was not intuitive and diagnostic

analyses were only available to a very limited extent. In order

to simplify programming and to optimize the process control,

AlzChem thus decided to use the AC 700F controller. This replaced

the PLC and was integrated into the existing Freelance

800F system without any problems.

This offers several advantages for AlzChem: The use of one

single engineering tool to configure the entire system simplifies

engineering and saves a significant amount of time during

commissioning. After transferring the program the system is

easy to understand and maintenance is simpler.

During the operating and maintenance phase, the wide range

of diagnostic options (sequence control-, hardware -, interlock

diagnostics), the intuitive graphical user interface and mature

alarm and report management allow costs to be cut. This

reduces downtime of the application and cuts maintenance

expenditures. All this improves the efficiency of the entire

system and the slightly higher acquisition costs compared to

a PLC amortize within a very short time.

Hartmut Rohner, Head of Electrical Systems, Instrumentation

and Control at AlzChem, is particularly impressed by the simple

and clear handling of the AC 700F controller and the Freelance

800F system. “It is easy for anyone to learn how to operate

the software and hardware. In contrast, it was practically impossible

to understand the standard program supplied by the

manufacturer together with the centrifuge.” Mr. Rohner also

sees clear advantages over other systems when it comes to

maintenance and faultfinding. Whereas with other manufacturers

faultfinding is only possible using a handheld device in

the field, Freelance 800F provides extensive analysis options

right in the control room. “Now I look at the status and can

see straight away where the error is. That is not possible that

simply in other systems.” This makes fault finding and maintenance

substantially easier.

Northam Platinum Ltd. is based in Johannesburg, South Africa,

and mines and produces precious metals. Convertors are

used to extract platinum from ore. These convertors are driven

using electrical motors. Until now, a PLC controlled the motors’

direct motor starters. This operating mode was not reliable

and efficient enough for Northam, as the motors thus operate

constantly at full output. That reduces the lifespan of the components

and causes higher repair and maintenance costs to

increase.

When the application was modernized and converted to frequency

converters to increase energy efficiency, the outdated

PLCs were to be replaced. Customer requirements were a

more compact controller, an improved presentation of alarms

and results and an excellent cost/benefits ratio.

Northam opted for the new AC 700F controller when replacing

PLCs for the converters. Northam has been using the Freelance

800F system to control its smelting furnaces and other applications

for many years and is convinced by the systems performance.

One AC 700F controller now regulates one variable-speed

drive. The motor output can be adjusted at any time to the

current operating requirements of the application, as frequency

converters can be simply driven by the controller. The adjustment

allows up to 50% of energy savings and processes can

be better controlled. The increase in efficiency resulting from

the intelligent speed control can be used in two ways: to increase

productivity or to keep production stable while simultaneously

reducing energy consumption.

Integration of the AC 700F controller into the existing Freelance

800F system and the easy engineering with just one engineering

tool, “Control Builder F” simplify commissioning and maintaining

of the entire application. The configuration is particularly

simple as the visualization is also created with Control Builder

F. Separate tools for programming the PLCs and to create

operator images are no longer needed. Technicians now only

need to handle a uniform engineering tool system wide. Production

data and information such as signal descriptions,

current and historical data, reports and detailed status information

can be recorded over several years in the information

management tool PGIM 800F.

As a result of its positive experience, Northam will modernize

additional converters and other small plants using the AC 700F

controller in the near future.