Telecom Equipment, Installation and Maintenance Practices
This section covers Telecom Equipment, Installation and Maintenance Practices. The exam tests site planning, safe installation, commissioning tests, and preventive maintenance of exchanges, base stations, and power systems.
Core rules and concepts
- Equipment includes exchanges/OLT, BTS, routers/switches, MDF/ODF/DDF, rectifiers, batteries, UPS, DG sets, and earthing. Each has clearance, ventilation, and access requirements.
- Installation sequence: site survey, layout, mounting, cable routing, labeling, termination, torque check, insulation/continuity tests, power-up, and commissioning.
- Earthing: equipment, lightning, and AC earths are bonded to a common earth grid but routed separately to reduce noise; measure earth resistance with a fall-of-potential tester. Bond racks and cable trays.
- Maintenance types: preventive (scheduled), predictive (condition-based), corrective (fault repair). Use checklists, alarm monitoring, spares, and MTTR/SLA tracking.
- Commissioning checks: input voltage, battery voltage, load current, VSWR for RF, optical power, insulation resistance, and alarm tests.
Worked example
A 48 V, 100 Ah battery bank supplies a 20 A load. Ideal backup = 100 Ah/20 A = 5 h. Apply 80% usable capacity and 80% ageing/derating: 5 × 0.8 × 0.8 = 3.2 h. If the site needs 4 h, the bank is undersized; add capacity or reduce load. This reasoning prevents a false '5-hour' claim.
Traps that cost marks
Ignoring derating and end-of-life capacity; working live without isolation; mixing AC and DC earths; failing to label cables; and accepting a battery voltage reading as proof of capacity. A voltmeter can show 48 V on a nearly dead bank.