What is In-Plant Voice Paging System? SAES-T-481

This article is about SAES-T-481 which is about In-Plant Voice Paging System and download SAES-T-481 PDF for telecommunication and electrical engineers, supervisors and project managers, telecom QCs, telecom QC Supervisors. This is saudi aramco standards of Telecommunication Engineering based on international codes and standards and useful for telecom and electronics engineering knowledge to get job as engineers, QC Supervisors and QC managers, Engineering managers and technicians.

SAES-T-481 PDF Download

SAES-T-481

In-Plant Voice Paging System

SAES-T-481 standard covers the minimum mandatory requirements for the design and installation of AC powered, in-plant party paging communication systems. These systems are specifically intended for use in Saudi Aramco industrial facilities, including Petroleum Refineries, Gas Oil Separation Plants (GOSPs), Natural Gas Liquid (NGL) Plants, and Water Injection Plants (WIPs).

The standard outlines the specifications and guidelines for the design and installation of these communication systems to ensure their effectiveness and reliability. It is important to note that the entire SAES-T-481 standard can be attached to and made a part of purchase orders, indicating its significance in procurement and implementation processes.

Design Requirements

The design requirements for the in-plant party paging communication systems outlined in SAES-T-481 are as follows:

4.1 Compliance: The design of the party paging communication systems must comply with NFPA 70 National Electrical Code (NEC) and the guidelines provided in SAES-B-068 (Electrical Area Classifications).

4.2 Power Supply Sources:
4.2.1 Power Source: The in-plant party paging communication system should be powered by an Uninterruptible Power Supply (UPS) system.
4.2.2 UPS System: The UPS system can be dedicated to the party paging system or shared with other systems. The UPS system’s backup capacity should meet the requirements specified in 4.2.6.
4.2.3 Compliance: The UPS system must comply with SAES-P-103 and SAES-P-104.
4.2.4 Operating Voltage: The operating voltage for the in-plant party paging stations should be 120 Volts AC, 60 Hz.
4.2.5 Load Capacity: The UPS system should have sufficient load capacity (KVA) to support the entire party paging system.
4.2.6 Backup Power: During commercial power failure, the UPS system should be capable of providing one of the following:

• 4.2.6.1 Minimum 4-hour battery backup capacity system in conjunction with a secondary engine-driven power generator system arranged according to NFPA 72, National Fire Alarm Code, 2007, Section 4.4.1.9.3, Secondary Power Supply.
• 4.2.6.2 Minimum 8-hour battery backup capacity system without the use of a secondary engine-driven power generator system.

4.3 Hazardous Areas: Paging stations, amplifiers, junction enclosures, plugs, and loudspeakers installed in hazardous (classified) areas as defined by the approved area classification drawing must meet NEC requirements for installation in such locations.

4.4 Acoustical Booths: Acoustical booths should be provided for party paging stations in areas where ambient noise levels exceed 80 dBA. The noise level inside the acoustical booths should not exceed 80 dBA.

4.5 Loudspeakers: Loudspeakers should be installed in areas where ambient noise levels exceed 90 dBA (refer to SAES-A-105).

4.6 Multi-Tone Generator: The in-plant party paging system should include a multi-tone generator capable of generating a minimum of six different types of tones for various emergency conditions such as yelp, warble, siren, and steady tone.

4.7 Priority-Override Capability: The multi-tone generator should have priority-override capability, allowing the most critical tones to override the less critical tones in the event of simultaneous or multiple emergency conditions. The control for the multi-tone generator should be located in the central control room.

4.8 Alarm Interpretation: The interpretation of each alarm tone should be established by the personnel in charge of the plant operations.

These design requirements ensure compliance, reliable power supply, appropriate installation in hazardous areas, adequate acoustic conditions, and effective emergency tone generation for the in-plant party paging communication systems.

Design

In the design of the in-plant party paging communications system, the following requirements are specified:

5.1 Line Balance Assembly:

• A line balance assembly should be installed in the system to reduce side tone, feedback, hum, and distortion. Whenever possible, the line balance assembly should be installed at the central location of the serving area.

5.2 Party Paging Systems:

5.2.1 Multi-Channel System: Only multi-channel in-plant party paging systems should be installed. The system should be capable of conducting a minimum of five simultaneous and full-duplex conversations. Each station should have paging capability and the ability to select other stations.
5.2.2 Operating Voltage: The operating voltage for in-plant party paging stations should be 120 Volts AC, 60 Hz.
5.2.3 Speaker Amplifier and Termination Points: All party paging stations should include speaker amplifiers and termination points for powering external speakers.
5.2.4 Disconnection of Handset: Station handsets should be designed to be disconnected from the communications network when the handset is not in use (on-hook).
5.2.5 Noise Cancellation: Handset microphones of party paging stations should be equipped with noise cancellation devices to minimize noise interference.
5.2.6 Retractile Handset Cable: The handset cable of party paging stations should be retractile and extendible to at least 180 cm.
5.2.7 Gain Amplifier: The handset should be equipped with a gain amplifier with an adjustable range.
5.2.8 Adjustable Volume: The volume level of the speaker amplifier should be internally adjustable.
5.2.9 Transformer-Coupled Output: The input and output of the speaker amplifier should be transformer coupled. The output side should have two taps for both 8-ohm and 16-ohm output impedance.

5.3 Speakers:
5.3.1 Compliance: Loudspeakers used for the in-plant party paging communications system should meet the requirements of UL 1480 (UL Standard for Safety Speakers for Fire Protective Signaling Systems) recommendations.
5.3.2 Impedance: The loudspeaker driver-coil (voice coil) impedance should be either 8 ohms or 16 ohms.
5.3.3 Construction: All speaker components, including the driver, horn, and mounting hardware, should be made of corrosion and impact-resistant materials.

5.4 Enclosures:

• The enclosures for the in-plant party paging communications equipment should comply with the following standards:
• NEMA type 12: For indoor, non-hazardous locations.
• NEMA type 4X: For outdoor, non-hazardous locations.
• For hazardous locations (Class I Division 1 & 2), the enclosures should comply with NEMA type 7 in addition to NEMA type 4X. The equipment, along with the enclosures, should be rated and labeled for use in classified locations (Class I – Div. 1) or (Class I – Div. 2) as per the requirements of SAES-P-100 paragraph 4.2.

5.5 Station Interconnection Cables:

5.5.1 UL Listed Cables: Cables should be UL listed for indoor and outdoor applications. Cables installed within a building should be listed as being resistant to the spread of fire in accordance with NFPA 70 National Electrical Code (NEC) Article 800-50 and Article 800-51.
5.5.2 Outer Jacket: The outer jacket of the cables should be made of hard service, flame retardant, moisture, and ultraviolet-resistant material to provide protection from oil, chemical, mechanical, and other environmental abuse.

These design requirements ensure proper line balance, functionality of party paging systems, appropriate speaker performance, suitable enclosures, and reliable interconnection cables for the in-plant party paging communication systems.

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