This article describes direct lines and dedicated hotlines by passing the PABX switch for direct access communications.
1. Telephone Hotline System Specification
2. Telephone Hotline System Codes & Reference
National Fire Protection Association (NFPA)
NFPA-70 National Electrical Code (NEC)
Article – 250 Grounding
Article – 800 Communications Systems
3. Telephone Hotline System Requirements
3.1. Direct line telephones shall consist of the following:
3.1.1. Single line, analog, black desktop telephone with touch-tone dialing capability.
3.1.2. Direct external PTT telephone lines that provide international dialing capability. These lines will bypass the PABX but will pass through the central office for international dialing.
3.1.3. Connections shall be between the PTT and other areas viz,
a. Emergency Command Center
b. Security Room
c. Utilities and Offsites Control Room
d. Control Room
e. Central Maintenance/Material Warehouse
f. Fire/Safety/Clinic or as specified by the project scope.
3.2. Hotline telephone systems shall consist of the following:
3.2.1. Red color, single line, no dial, wall mounted hotline telephones
3.2.2. Red color, single line, no dial, desktop hotline telephones
3.3. Two-way ring down circuits
3.4. Internal Hotlines telephone connectivity shall be provided as specified by project.
3.5. External Hotlines telephone connectivity shall be provided as specified by project.
3.6. These hotlines are directly connected from point-to-point bypassing the PABX and powered by external ring down circuits. When any hotline phone is taken off-hook, the hotline telephone on the other end of the connected phone line rings until answered. When the ringing phone is answered, the two parties have direct full duplex voice connectivity. The connection terminates when either party places the telephone on-hook. When both telephones are returned to on-hook, the hotline circuit is again ready for another hotline telephone call. All hotlines are direct station-to-station communication with no ability to choose between different phones ringing on the receiving end.
3.7. The hotline system shall be designed to utilize 230 Vac @ 60Hz. power. Manually selectable 127/230 Vac power supply units or equipment shall not be used.
3.8. A dedicated UPS power connection to the ring down circuit is required at each telephone location. The UPS system shall be capable of powering the ring down circuit for not less than 12 hours as per HCIS directive SEC-08. The ring down circuit shall supply off-hook ringing current to the hotline circuit.
3.9. Where direct lines and hotline systems use outside building copper cable, the copper cable shall be shielded 22 AWG. All cables shall be installed in accordance with NEC.
3.10. Where hotline connections are required outside the site, cabling may be done by Others.
4. Telephone Hotline System Testing
4.1. All equipment shall be factory tested according to the manufacturer’s specifications.
4.2. Field testing shall simulate a realistic operational environment as may be encountered and ensure equipment compliance with the specifications.