Underground Mains Services Defined

January 31, 2019

Underground mains services are routed from a primary utility line. They travel below the ground, rarely overland, then they arrive at a structure. By definition, an energy transforming junction bridges the main line and the service branch. For water, a pressure reduction mechanism is employed for this purpose. For electricity, special substations transform high-tension currents and voltages into consumer-level power. Sticking with electricity, we're about to visit an electrical substation.

Mapping Out an Electrical Substation

Overhead powerlines make a beeline towards a primary city substation. Over 132,000 Volts of power is dropped down to 66,000 Volts. Transformers and city switchgear continue dropping the voltage as distribution lines radiate out across the region. At some point, an end-line substation is reached. It's here that the power terminates as a three-phase 415-Volt, four-wire line or as a single two or three line 230-Volt power supply. The underground mains services trench takes over from here, heading as it does towards homes, offices and businesses.

Routing the Mains Lines

Away from the overhead distribution cables, the new power services cable joins a group of pipes as they zip down the length of a long street. A high-pressure mains water pipe and a gas pipe are installed to one side, and there's space left over for the cable. This is a mains utility services trench. It's the main branch, and it feeds out towards dozens of smaller branches. Adequately separated, the cables and pipes are colour coded so that there's no mistaking their duties. Orange for electricity, yellow for gas, and blue/white for water, the separated utility lines make their way forwards. Incidentally, all mains services are dangerous. After all, even water becomes dangerous when it's held under pressure. To minimize the danger, trenching technicians keep all services at least 300-mm below ground. And that's a minimum. A depth of up to 1-Metre is favoured by most trenching services, but this decision is left to the discretion of the installer, who refers to the relevant regulations in his trenching rulebook.

By definition, underground mains services are installed deep, and they're situated in a layer of carefully laid bedding. They can be traced back to water and gas distribution houses, or, as is the case with electrical power, back to a power transforming substation. However, due to undisciplined landowners and construction services, those depths can dwindle dangerously. An expert excavation company prepares for all such eventualities. The services are labelled, separated, and sunk to the correct depth. Job done, the team carefully checks their connections. They leave, but only after they've filled the trench and commissioned the service connection.

Optimized by NetwizardSEO.com.au