SAES-T-151 PDF - D.C. Power Systems - PDFYAR - Engineering Notes, Documents & Lectures

This article is about SAES-T-151 which is about Telecommunications D.C. Power Systems and download SAES-T-151 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-151 PDF Download

SAES-T-151

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Telecommunications D.C. Power Systems

SAES-T-151 is a Saudi Aramco Engineering Standard that outlines the minimum mandatory requirements for Communications Power Systems in Saudi Aramco communications facilities. These facilities include central telephone switching offices, microwave terminals, repeater stations, and UHF/VHF radio equipment. The standard sets forth the guidelines and specifications that must be followed when designing, installing, and operating power systems for these communication facilities. It ensures that the power systems meet the necessary safety, reliability, and performance standards to support the operation of the communication equipment effectively.

Telecommunications D.C. Power Systems Design

According to the SAES-T-151 standard, the design requirements for battery rooms in Saudi Aramco communications facilities are as follows:

4.1 Battery Rooms – Ventilated

4.1.1 The battery rooms must have proper ventilation systems in place to prevent the accumulation of hydrogen gas and maintain the designated temperature. The ventilation system should ensure that hydrogen accumulation remains below 2% by volume. The maximum rate of hydrogen evolution is specified as 0.000269 cubic feet per minute per charging ampere per cell at 25°C. The worst-case scenario is considered when maximum current is forced into a fully charged battery. Battery rooms must be vented to the outside air. The ventilation system should provide a minimum of one complete air change every three hours. Return air ducts from air conditioning systems in battery rooms are prohibited. (Reference: HVAC Standard SAES-K-002 Section 6, Battery Rooms, or SAES-K-003, Communications Buildings).

4.1.2 A battery room that meets the ventilation requirements mentioned in 4.1.1 at all times is considered a non-classified area. As a result, explosion-proof enclosures are not necessary for electrical appliances installed in these rooms.

4.1.3 Room lighting in the battery rooms must comply with the guidelines outlined in SAES-P-123.

These requirements ensure proper ventilation and safety measures are in place for battery rooms within Saudi Aramco communications facilities.

Battery Sizing

According to the SAES-T-151 standard, the battery sizing requirements for communications systems in Saudi Aramco are as follows:

4.6.1 The battery reserve capacity should be sufficient to sustain the operation of the communications load during the busiest hour (referred to as “full DC load”) for a period of 8 hours when standby AC power is available. For unattended remote offices, the battery reserve period should be 12 hours. The full DC load can be determined based on actual measurements of an existing system or estimated using calculated loads as an alternative. Battery sizing takes into account the maximum system voltage required, the minimum allowable voltage, and the duty cycle. (Reference: IEEE 485).

4.6.2 The final voltage of each battery cell should not be lower than 1.75 volts for lead-acid batteries or 1.1 volts for Nickel Cadmium batteries.

4.6.3 The battery reserve capacity is determined using the following equation:
AH = L x BT x TC x AC x DF
where:
AH – Ampere-hour capacity of the battery
L – Full DC load in continuous amperes
BT – Backup time (specified as 8 or 12 hours)
TC – Temperature compensation factor (1.19)
AC – Age compensation factor (1.25)
DF – Design factor (1.10)

4.6.4 The minimum number of series-connected cells and the end-of-discharge voltage per cell should comply with the guidelines outlined in SAES-P-103.

These requirements ensure that the battery reserve capacity is appropriately sized to meet the power demands of the communications load during specified periods and that the voltage levels are within acceptable limits.

FAQs about SAES-T-151 PDF Download

Scope of SAES-T-151:

SAES-T-151 specifically focuses on the minimum mandatory requirements for Communications Power Systems in Saudi Aramco communications facilities. These facilities include central telephone switching offices, microwave terminals, repeater stations, and UHF/VHF radio equipment.

Purpose of SAES-T-151:

The standard aims to provide guidelines and specifications for the design, installation, and operation of power systems in communication facilities. It ensures that the power systems meet the necessary safety, reliability, and performance standards to support the effective operation of the communication equipment.

Key areas covered by SAES-T-151:

SAES-T-151 addresses various aspects related to Communications Power Systems, including but not limited to:
Power system design considerations, such as load requirements, redundancy, fault tolerance, and protection measures.
Power source options, such as commercial power supply, uninterruptible power supply (UPS), generators, and battery backup systems.
Power distribution systems, including distribution panels, grounding requirements, and electrical protection devices.
Safety considerations, including electrical safety practices, grounding and bonding requirements, and protection against electrical hazards.
Environmental considerations, such as temperature, humidity, and ventilation requirements for power equipment rooms.
Maintenance and testing requirements for power systems to ensure ongoing reliability and performance.

SAES-T-151 PDF – D.C. Power Systems