18 August 1998
computer, eliminating the need for the separate communication processor described in this manual for
systems with multiple communication channels.
7. POWER LINE CONDITIONER. Power line conditioners protect UMCS equipment from power line
fluctuation and noise which can result in computation error, erratic operation, loss of data, overheating,
circuit burnout, and in some cases, system shutdown. The power line conditioner provides attenuation of
the power line noise by using isolation transformers. It provides a regulated voltage source by using solid
state devices that provide fast response to changes in incoming voltage or load conditions; however,
they do not protect the UMCS from power outages. Power line conditioners will be provided for all central
station equipment, island station equipment, smart field panels and remote terminal units except
equipment for which the design includes an uninterruptible power system (UPS). Each power line
conditioner will be sized for 125 percent of the required load for the connected equipment.
8. UNINTERRUPTIBLE POWER SYSTEM. An uninterruptible power system will be provided for
UMCS equipment which must operate continuously under all conditions including loss of commercial
power. Static uninterruptible power systems provide continuous, conditioned, single-phase AC power
while operating either from an AC line power source or from DC storage batteries. The batteries will be
sized for a minimum backup time of 15 minutes or as required by the installation and application. The
UPS also protects UMCS equipment from power line fluctuation and noise similar to the power line
conditioner. Uninterruptible power systems will be sized for 125 percent of the required load for the
9. INTERCOMMUNICATIONS SYSTEMS. An intercom system can be used to communicate with field
personnel while performing checkout, maintenance, and trouble shooting tasks for UMCS. The intercom
system can also facilitate the checkout and acceptance of the UMCS by providing communication
between field equipment panel locations and the central station or island station. Implementation of an
intercom system will require dedicated circuits between the central station or island station intercom and
each intercom station, or the encoding of voice communications on the data communication systems.
Hand held FM radio units are an alternative to intercommunications systems.
10. INTERFACE AND FUTURE EXPANSION. When specifying the central station or island station,
provision must be made for additional peripherals such as workstations which may be required in the
future when expanding or modifying the UMCS. In addition, provision may be necessary for a central
station to communicate with additional island stations which may be required in the future. Hardware and
software communication protocol documentation, required to implement a system expansion, must be
provided by the original system manufacturer via appropriate license agreements. If future planning at
the facility indicates an expansion and the potential need for both a central station and one or more island
stations, costs for the system can be deferred to the future project by installing the field equipment with
only a single island station; or, depending on agency criteria and cost tradeoffs, it may be more prudent to
initially procure the central station and one or more island stations.
11. CONSOLE AND ACCESSORIES. The central station and each island station will contain necessary
accessory equipment to support operation of the system, including a desk type console, swivel chairs with
casters, paper trays for printers, and storage enclosures for test equipment, magnetic cartridge tapes,
printer paper and other supplies. The console will contain sufficient surface area for the operator's
workstations and work area. Equipment cabinets and accessories will be color coordinated. Figure 2-1 is
typical for a central station or island station equipment room.