Control System Requirements in Control Buildings

1. SCOPE ………………………………………………………………………………………………………………..
2. REFERENCES ……………………………………………………………………………………
3. GENERAL REQUIREMENTS ……………………………………………………………………………………
3.1 General ……………………………………………………………………………………
4. GUIDELINES ……………………………………………………………………………………
4.1 Considerations ……………………………………………………………………………………
4.2 Location of Control Rooms ……………………………………………………….
4.3 Number of Control Rooms ……………………………………………………….
4.4 Control Room Design ……………………………………………………………………………………
4.5 Size of Control Room ……………………………………………………………………………………
4.6 Expansion Provision ……………………………………………………………………………………
4.7 Minimum Control Room Requirements ……………………………………………………….
4.8 Average Control Room Requirements ……………………………………………………….
4.9 Special Purpose Control Room Requirements …………………………..
4.10 Motor Control Center ……………………………………………………………………………………
4.11 Emergency Power Supply with Batteries ……………………………………………………….
4.12 Security of Control Rooms ……………………………………………………….
4.13 Optional Requirements For Control Rooms of Control Rooms …………………………..
4.14 Classes of Control Rooms ……………………………………………………….
4.15 Layout Of Control Rooms ……………………………………………………….
4.16 Electrical Details of Control Rooms……………………………………………………….
4.17 Pneumatic Details of Control Rooms ……………………………………………………….
4.18 Lighting Requirements For Control Rooms ……………………………………………………….
4.19 Room Finish ……………………………………………………………………………………
4.20 Heating, Ventilating and Air Conditioning (HVAC) …………………………..
4.21 Fire Prevention For Control Rooms ……………………………………………………….
5. REVISION HISTORY ……………………………………………………………………………………

1. Scope
This standard defines guidelines for the design of industrial Control Rooms from where
operators can control an entire process plant.
Control room structural design, detail HVAC design, and detail fire protection design is not within
the nominal responsibilities of a Control System engineer, therefore, this detail work is not
included in this scope. Detail electrical engineering of the control room and the apparatus inside
is not included in this scope. Any Items in this standard pertaining to these disciplines are
recommendations only.
This practice is not intended to satisfy guidelines established by the Nuclear Regulatory Agency
for Nuclear Control Rooms.
2. References
Reference is made in this standard to the following documents. The latest issues, amendments,
and supplements to these documents shall apply unless otherwise indicated.
SABIC Engineering Standards (SES)
F03-G01 Fire Protection of Buildings
X01-E01 Control System Design Criteria
International Society of Automation (ISA)
RP 60.1 Control Center Facilities
3. General Requirements
3.1 General
3.1.1 This standard applies to all projects that require a control room, unless superseded by
SABIC. It is the responsibility of the Control Systems Lead Engineer to lead the project team
in locating, sizing and then detailing the contents of the control room or rooms.
3.1.2 To successfully execute this control room design work, the Control Systems Group shall
work closely with the Electrical, Architectural, Structural, HVAC, and Fire Protection
Departments.
3.1.3 Additionally, SABIC process control expert shall be consulted during the control room
design.
3.1.4 Any conflicts between this standard, SES and industry standards, engineering drawings,
and contract documents shall be resolved at the discretion of the Buyer.
3.1.5 Buyer exceptions to this standard will be detailed on the purchase order.
3.1.6 Vendor exceptions to this standard shall be included in the quote.
3.1.7 Mention of any trade names in this standard is for the sake of discussion only. No
endorsement of or preference of any particular vendor is implied.

4. Guidelines
4.1 Considerations
4.1.1 The need for control rooms and their approximate location shall be decided between the
Engineering Contractor and SABIC during the conceptual stage of a project. The exact
location, size, and internal layout will be firmed as detailed engineering information is
developed.
4.1.2 The design objectives of the control room must be discussed and documented for approval
before detail design begins.
4.1.3 Control Room shall comply with the requirements of ISA RP-60.1
4.1.4 Some design objectives that shall be examined are:
a. Type of plant control, for example manual versus automatic.
b. Type of control equipment located in the control room, for example single loop
controllers, strip chart recorders, and annunciators, versus interactive CRT color
graphic systems (DCS, PLC, or computer based).
c. Type and location of; data acquisition, logging, analysis, and storage hardware.
d. Number of operators and other support personnel.
e. Type of emergency control required.
f. Space requirements for documents, like procedure manuals and electrical schematics.
g. Room classification.
4.2 Location of Control Rooms
4.2.1 SABIC will normally volunteer a recommendation for the control room location because their
process and operations personnel know the process best.
4.2.2 The type of process will tend to dictate the control room location. If the process requires a
large number of operator interactions, for example sampling, adding ingredients manually,
or frequent manual washing operations between batches, then the control room will
normally be located as close as possible to all the interaction areas.
4.2.3 If the process requires one operator to monitor a very large area, then the control room
occupied by that operator will be located away from the process and elevated. This location
allows the operator to see the process plant through observation windows.
4.2.4 If the process is hazardous from an explosion point of view, then the control room will
normally be located far enough away from the process area or be designed as blast
resistant so that the control room interior could survive a major accident.
4.2.5 Other process systems may not explode, but their hazards are attenuated by distance.
Examples are flammable products, chemicals that are toxic, nuclear products, and biological
products.
4.2.6 Control rooms in these instances may be protected from the hazard by distance or by a
combination of barrier walls, containment apparatus or blast resistant construction.
4.2.7 The following guidelines shall be used as a minimum:

a. Locate the control room above flood prone areas.
b. Locate the control room so that it is accessible for fire fighting.
c. Locate the control room near the process considering the items listed above.
d. Locate the control room near the most critical part of the process and arrange a clear
view of the process through the windows of the room.
e. Locate the control room so that the room interior would not require a hazardous area
electrical classification. This can be accomplished by providing a positive pressure for
the control room with respect to the process area.
f. The control room location shall not allow process or service fluids or gases to pass
through the room.
g. Locate the control room so as to facilitate expansion.
h. Have the finished floor level of the control room at least six inches (150 mm) higher
than the process area level.
4.3 Number of Control Rooms
4.3.1 Normally SABIC will recommend the total number of control rooms, as well as the location
of the most critical room.
4.3.2 If SABIC defers this to the Engineering Contractor, then additional fact finding will be
necessary on the part of the Engineering Contractor’s team.
4.3.3 The number of operators planned for each area plus the duties they are expected to perform
during a shift shall be determined from interviews with SABIC process expert. Next, the
territory these operators are expected to cover and their specific duties shall be estimated.
With this information, the number of control rooms can be proposed to SABIC for
acceptance.
4.4 Control Room Design
4.4.1 Operator comfort shall be met by satisfying the following items in the control room:
a. Ample fresh air (positive pressure).
b. Controlled temperature and humidity.
c. Reduced noise levels
d. Adjustable lighting levels.
e. Chairs
4.4.2 The following should be within walking distance:
a. Water cooler.
b. Rest rooms.
c. Break room.
4.4.3 Equipment to be installed in the control room may require control room designs that are
more stringent than those recommended for operator comfort. For example, some brands of
Distributed Control Systems (DCS) units require tight regulation of temperature and humidity
to maintain their warranty. Also, the computers that run these DCS units are sensitive to dirt
because of their disk drives. To meet the requirements of DCS units, it is normally

recommended that control room traffic be restricted to exclude access of workers covered
with dirt or dust.
4.4.4 Locating the computers with their fixed and removable disk drives away from the control
room is another method to solve the dust problem. This incrementally increases overall cost.
4.4.5 It is possible to purchase DCS units that are NEMA 12 rated if the advantage of having the
display and control units being accessible to many operators, who may be covered with dust
from the process area, is worth the added expense.
4.4.6 Seismic considerations, if they are a part of the facility construction requirements, require
bolting the control panels to the floor so that the panels cannot tip over or move in the event
of an earthquake.
4.5 Size of Control Room
4.5.1 In very early conceptual work on a project, it is sometimes necessary to locate and size a
control room even though almost no information is available. In these instances, it is
recommended to assume 20 feet by 16 feet with 9 foot ceiling and provision for expansion.
4.5.2 When more information is available, the control room size can be determined.
4.5.3 For power plants and refineries, the above size minimum needs to be in the range of 50 feet
by 25 feet.
4.5.4 The best method to use to determine the number and size of instruments, panels, CRT’s,
printers, and desks, and then draw a room around them. However, in retrofit projects, the
room size may be dictated by the fact that existing large structures that are part of the
production equipment may be too costly to move. When the control room size is limited and
it appears to be too small for all of the equipment that should be in it, the following
alternatives should be evaluated:
a. Instruments such as strip chart or circular chart recorders may be deleted and the same
information may be presented to the operator by use of modern computer driven
histograms and trend records that are stored on disk instead of paper.
b. Single loop process indicators may be deleted and the same information displayed on
color graphic CRT units driven by DCS equipment or computers.
c. Hardwired annunciators may be deleted and the information displayed by alarm
handling packages that may be part of the same computer driven graphics packages
mentioned above.
d. The input/output (I/O) signal conditioning units for the control system may be located in
other areas of the plant.
e. These techniques of removing dedicated hardwired instruments and substituting
computer processing power and fast memory will allow a lot of information to be
controlled effectively from a small control room.
4.6 Expansion Provision
4.6.1 Provision for future expansion is standard procedure for control rooms. Future expansion in
width or length is a normal consideration, but provision for adding a second story to a
control room is also an excellent consideration.
4.6.2 If future expansion to a second story is contemplated, the second floor should be used for
relocating seldom used control equipment for example I/O racks. It is not practical to expect

one operator to run the upper control room (future) while a second operator runs the lower
(existing) control room.
4.6.3 It is helpful to consider that a training or break room might be added to the second story if it
is planned in advance.
4.7 Minimum Control Room Requirements
4.7.1 The following list is a minimum requirement for a control room. This minimum will be less
costly and will be less sophisticated than an average or a special purpose control room:
a. Emergency stops with resets.
b. Telephone.
c. Alarm displays.
d. Process control devices (for example controllers, recorders, meters, lights, buttons,
switches).
e. Color Graphic CRT’s.
f. Sufficient controls and displays to detect any abnormal condition and to bring the entire
process to a safe shutdown condition. This shutdown may ruin a product batch, or
damage some equipment, but it is guaranteed to stop the equipment.
g. Page/party system.
h. Fire/smoke alarm.
i. Hazard alarm (gas, leak, radiation).
4.7.2 The following are not controls, but are necessary:
a. Fire extinguisher.
b. Utility receptacles.
c. Storage cabinet.
d. Clock.
e. Sprinklers or other fire protection systems.
f. Writing surface.
g. HVAC.
h. Windows (unless Process Hazards Analysis forbids it).
4.8 Average Control Room Requirements
4.8.1 An average control room includes all of the above items from the minimum list plus a few
more items that would be expected in the average control room:
a. Alarm printer.
b. Report printer.
c. Closed circuit television (CCTV) for process observation.
d. Specialized instrument controls complete with displays, recorders, and alarm printer.
e. Sufficient controls and displays to be able to start the entire process.

f. Sufficient controls and displays to be able to stop the entire process in a manner that
minimizes batch spoiling and equipment damage.
g. Control capability to tune the process.
h. I/O panel or rack (to drive the displays).
i. Data acquisition devices and displays.
j. Fixed radio station to communicate with personnel carried walkie talkie units.
4.8.2 The following are not controls, but are usually included:
a. Operator desk area and bookshelf.
b. CCTV for safety or personnel.
c. Computer room flooring. This detail is expensive, but highly recommended because it
permits maximum flexibility for changes to equipment.
d. Plant manuals, checkoff sheets, logs, procedures, schematics.
e. Chart paper, pens, printer paper, indicator lamp bulbs.
4.9 Special Purpose Control Room Requirements
4.9.1 A special purpose control room includes most of the above items plus any unusual items
required by the process or client. In some cases, it is accurate to say that these things do
not belong in a control room, but nevertheless these examples have been observed in
industry.
4.9.2 Control capability to perform advanced offline calculations that improve quality, throughput,
and minimize energy.
4.10 Motor Control Center
4.10.1 A caution is offered here. If MCC’s are installed in a control room, the EMI that occurs when
a large motor is started or stopped can cause spikes in sensitive low voltage equipment.
This interference can be difficult to solve unless the MCC units are physically mounted in
another room.
4.11 Emergency Power Supply with Batteries
4.11.1 A caution is offered here. Because solid state inverters built into these power supplies may
emit EMI, this location should be discouraged. Further, the batteries represent a high
maintenance item because of possible gas leakage, possible acid leakage, and their heavy
weight.
4.12 Security of Control Rooms
4.12.1 Access to the control room may be limited by providing key-locked doors, badge reader
entrance locked doors, or code button locked doors.
4.12.2 Clean room requirements vary per industry and are too extensive to cover in detail here.
Three types of clean control rooms are as follows:
a. Clean control rooms for volume food processing will require periodic rinsing of the
control room with strong disinfectant liquids or steam. This requires no computer room

flooring, minimum horizontal conduit runs, washable keyboards, few or no storage
cabinets and usually stainless steel enclosures everywhere.
b. Clean control rooms for pharmaceutical areas or bio-genetic engineering may not be
rinsed or steamed periodically, but they will require use of stainless steel for enclosures
and will be separated from the working portion of the plant by walls and window design
that permit zero passage of bacteria and virus. Further, to get from the control room into
the production area, an extensive maze of interlocked doors, different pressures, and
clothing change areas may be required.
c. Clean control rooms for processing optical grade products for example photographic film
stock or wafer manufacturing do not require rinsing or steaming, but they do require
frequent wet wiping of all surfaces and wet mopping of floors. They require a design that
minimizes production of dirt and dust, so printers are normally not installed. Further,
they do not require the door interlocking that may be used in a pharmaceutical facility.
4.13 Optional Requirements For Control Rooms of Control Rooms
4.13.1 Small laboratory facilities with sink and eyewash station
This may require a sloped floor with drain that harmonizes with the need for a raised
computer room floor in the part of the room that contains most of the electronics and
displays. A caution is warranted here: If a laboratory is integral with a control room, the
possibility of chemical spills may force the evacuation of the control room when such
evacuation is contrary to the needs of the process. Laboratory facilities integral with a
process control room shall be discouraged.
4.13.2 Personnel lockers
4.13.3 Process material supplies
4.13.4 Spare parts supplies
The concept of a control room is to house process control equipment and the operators who
use that equipment to run the complex processes. Also, the control room is intended to
remove distractions from operators, who are skilled individuals who have to solve complex
problems in a short time. When operators have distractions not related to their primary duty
of keeping the process running smoothly, then process efficiency may suffer.
4.13.5 Some facilities require special purpose control rooms with features as listed, and the entire
system can be successful.
4.14 Classes of Control Rooms
4.14.1 Local Control Room
Usually a small room with minimum controls that is manned only part time and is used for
start-up of processes that have a periodic need for close manual observation. This room will
probably not even contain the minimum items listed above because of its occasional use.
4.14.2 Process Control Room
Located near the process to be controlled. It is usually manned when the process is running
normally. Process control setpoints will be edited from this location.
4.14.3 Plant Control Room

Located near central operations or central maintenance. For the process or manufacturing
industries, this is used to monitor and alarm only, and is not normally used to control the
process. Large power plants and large refineries will normally not have a process control
room named as such, instead it is called a plant control room. These plant control rooms are
manned around the clock and control setpoints will be edited from this location.
4.15 Layout of Control Rooms
4.15.1 The room should be arranged for ease of operation, smooth ingress and egress, ease of
maintenance and safety.
4.15.2 It is preferred that the control devices are arranged in a format that follows:
a. Equipment geographic layout.
b. Material flow.
c. Controls and alarms follow consistent color coordination.
d. Emergency stops are located closest to the operator (large buttons with shrouds).
e. Controls nearest the operator will be most frequently used and conversely, controls
furthest from the operator will be least frequently used.
f. Room layout and panel layout shall be designed to yield the best readability of all
parameters from the operator’s normal seated position, but all devices shall be readable
from a standing position with minimum glare.
g. Devices shall be specified to be readable from at least 30 degrees off center.
h. A few process parameters may require dedicated, oversized meters that are easy to
read from anywhere in the control room.
i. If separate alarm units are used, a traditional location for them is slightly above the
operators’ vision.
j. Panel location and layout shall consider repair and replacement of instruments,
recorders, and CRT’s.
k. Additional investment in hinges, rollers, slides, coiled cords and easy to plug in and
unplug multi-pin connectors, should be part of the quality design details.
l. A mandatory requirement of the NEC Article 645, requires a means to disconnect power
to all apparatus in an electronic computer/data processing room. This may apply to a
control room. A discussion with the Electrical Engineering lead should help resolve if
this is applicable to a control room, because many processes may become more unsafe
if all power is removed from the control devices that may be installed in the control
room.
m. A disconnect for the air movers and dampers (for fire purposes) is recommended near
an exit door.
n. Most modern control rooms will have no need for pneumatic supply or control.
o. Computer room flooring is strongly recommended as the standard installation because it
permits maximum flexibility. But certain processes may release gases that are heavier
than air and could collect in a shallow pit like a computer room floor. These
considerations may suggest not having a computer room floor.
4.16 Electrical Details of Control Rooms
4.16.1 Electrical details shall be reviewed with the Lead Electrical Engineer.

4.16.2 Within the control room, panels shall be rigidly mounted with access for:
a. Conduit: both rigid and flexible.
b. Cable tray.
4.16.3 Panel assemblies and all control room equipment shall meet local and state codes. Refer to
the contents of the SES-X01-E01 for details.
4.16.4 Good electronic wiring design practice has wiring separation between low voltage, medium
voltage, and high voltage devices.
4.16.5 RFI immunity specification
No installed components should be disturbed by the operation of a 5 watt portable walkie
talkie transmitting from any position inside the control room.
4.16.6 All components on panels shall have membrane key pads and oil-tight pilot devices if the
operator is expected to come in to the control room and operate devices just after a manual
process task that is dirty or oily.
4.17 Pneumatic Details of Control Rooms
4.17.1 Provide easy access to monitor the flow rates, and pressure of the instrument air for all
instruments in the room.
4.17.2 Provide easy access to the final filters and water/oil traps.
4.17.3 Slope pneumatic headers to permit manual drainage into a floor drain.
4.18 Lighting Requirements For Control Rooms
4.18.1 Fluorescent fixtures with diffusers are recommended as part of the control room lighting
system. Units shall be wired to provide 50 percent and 100 percent lighting from each set of
fixtures per wall switches. If reliable fluorescent dimmer systems are available, they may be
preferred.
4.18.2 Supplementing the fluorescent units shall be incandescent units on several dimmers. These
incandescent units shall be adjustable in beam spread and direction with few tools. Control
rooms that use DCS or color graphic CRT units will primarily use the dimmed incandescent
units during normal operation.
4.18.3 Emergency lighting in the control room shall provide at least 10 foot candles of light on the
panels, consoles and keyboards if these apparatus have a UPS that allows them to operate
through a total power outage.
4.18.4 Emergency lights with illumination levels recommended by the NEC shall be provided for
safe personnel evacuation.
4.19 Room Finish
4.19.1 Detail design of the room structure and finish will be provided by the Structural and
Architectural Departments.
4.19.2 Some general guidelines are as follows:

a. The internal walls should be smooth to avoid dust accumulation, and painted a light
color.
b. Acoustic tile ceilings are recommended.
c. Floors shall be easy to clean.
d. If carpet is requested by the client, it shall be of anti-static design to prevent damage to
devices that may be touched by operators for example CRT’s, light pens, and mice. An
alternate caution is to post a warning to maintenance personnel if this conductive type of
carpet is installed to warn them that repair to live circuits entails higher risk when
standing on a conducting surface.
e. Doors should be metal with large glass inserts, and shall include panic hardware.
f. Windows should be provided because they provide a psychological link indicating the
room is less confining than it really is, and they permit direct observation of part of the
process system. If the process can explode, it is usually not recommended to have
windows facing the potential sources of explosion.
g. Noise levels inside the control room should be designed to keep the background down
below 65 dBA when the process system is running normally.
h. The acoustic environment should enable easy operator to operator communication, but
allow audible alarms to be clearly heard.
4.20 Heating, Ventilating and Air Conditioning (HVAC)
4.20.1 The HVAC Department will provide detail design for the systems needed to condition the
control room. Some general guidelines are as follows:
a. Heating and air conditioning shall be provided to furnish 30 percent to 60 percent
relative humidity and 72 degrees Fahrenheit plus or minus 2 degrees (22 degC). The air
handling and chilling system should be designed with a redundant system, with
sufficient capacity to keep setpoint satisfied with half the system out of service.
b. A positive pressure with respect to the process area is normally required to keep dust
and gases out.
c. The HVAC system shall be interlocked with the fire protection system to shutdown all air
handlers and close all dampers in the event smoke or heat is detected.
d. Fresh air inflow into the control room should be at least 15 cfm per occupant, with air
velocities not to exceed 45 fpm, and without noticeable draft. Exceptions to this may be
required when chilled air is forced through control panels or computers that are
significant heat producers. (Verify with HVAC Department).
e. Design should keep temperature differential between floor and head level less than 10
degrees F.
f. The Control System Lead Engineer shall advise HVAC of the apparatus heat load.
4.21 Fire Prevention for Control Rooms
4.21.1 The control room fire prevention system shall comply with SES-F03-G01 requirements.
Some general guidelines are as follows:
a. Control rooms are normally protected by smoke detectors linked to a pre-charged
sprinkler system. The sprinklers built into the control room ceiling are normally
pressurized dry. If the smoke detectors sense smoke, the system charges the sprinkler
headers with water. Then the heat sensitive fuse in each sprinkler head will only melt
when the local temperature melts the fuse.

b. The under-floor areas in control rooms are normally protected by smoke and heat
sensors that inject carbon dioxide into the under-floor areas to quench the fire. Carbon
dioxide is not used for the main room.
c. Halon is no longer recommended to protect control rooms because of federal regulation.
d. Other products may be recommended to replace Halon if they satisfy the following three
requirements:
 Safe to humans.
 Extinguishes fires.
 Not injurious to the ozone layer.
e. Portable dry chemical extinguisher shall be installed adjacent to control room doors.
They are sometimes the recommended choice for fire protection in a normally manned
control room instead of a pre-charged sprinkler system.

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