Vandalised BC Hydro transformers cause oil spill and days of outages

Between April and July 2019, at least four BC Hydro pad-mounted transformers in the Mt Seymour-Parkgate area of North Vancouver were deliberately damaged, apparently using some kind of saw and drill. In each case the transformers tripped, cutting power to nearby neighbourhoods, restaurants and grocery stores, in one case for three days. In one incident roughly 1,000 litres of mineral oil leaked from a damaged unit, but the gravel base beneath it stopped the oil seeping into the grass. BC Hydro said the tampering posed serious safety risks, including the possibility of a fire or an explosion, and put repair costs at roughly 150,000 Canadian dollars, not including lost business or spoiled food at affected premises. The utility said the incidents, which it dated to 2 and 24 April, 1 May and 2 July 2019, were suspected to be connected, and police were investigating.

Deliberate damage to pad-mounted transformer enclosures with what BC Hydro described as some kind of saw and drill. Pad-mounted units serving underground distribution are sited in publicly accessible locations such as pathways and lawns, and rely on mineral oil for cooling.

1. Pad-mounted transformer enclosures in publicly accessible locations should be assessed for tamper resistance, given the outage and safety consequences of forced entry.
2. Fail-safe tripping on loss of cooling oil is an important backstop and its correct operation should be verified as part of design and maintenance.
3. Where repeated interference with distribution equipment is detected, operators should link the incidents, report them to police early and consider additional surveillance or physical security.
4. Oil containment measures such as gravel bases reduce ground contamination when a transformer loses oil and should be checked during inspections.

theprogress.com/2019/07/10/vandalized-bc-hydro-transformers-cause-power-...