IESO Schedules Two Voltage Reduction Tests for July 23

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VAUGHAN, Ontario, July 15, 2013 (GLOBE NEWSWIRE) -- Although not expected to negatively impact electricity consumers in its service territory, PowerStream is notifying customers of province-wide voltage reduction tests planned by the Independent Electricity System Operator (IESO) for Tuesday July 23, 2013.

There will be two tests conducted on that day, a three per cent voltage reduction starting at 10:00 a.m. DST, followed by a five per cent reduction starting at 2:00 p.m. DST. Each test will last approximately one hour.

PowerStream, along with all other local electricity distribution companies in the province, are subject to voltage reduction tests which are conducted by the IESO once every 18 months. The IESO runs these tests to assess emergency procedures, ensure staff familiarity and to identify any deficiencies. Voltage reductions are implemented as emergency control actions to manage grid reliability under conditions of high demand combined with limited supply.

PowerStream is working to notify key account customers of the voltage reduction tests directly through their account representative.

Should unforeseen circumstances require the voltage reduction tests to be postponed, the alternate date and times are Thursday, July 25, 2013 at 10:00 a.m. and 2:00 p.m. DST.

For additional information on voltage reductions please visit the IESO website or contact the IESO Customer Relations at 1-888-448-7777.


  • "The vast majority of consumers do not notice voltage reductions as they are usually within industry standards specified for electrical equipment used by residential and commercial customers," explained Brian Bentz, PowerStream's President and Chief Executive Officer. "However, some sensitive equipment during a voltage reduction could be affected depending on the consumer equipment configuration."


  • Voltage reductions have been performed in the past as part of the IESO's routine testing protocols and, under extreme circumstances, to prevent blackouts. The last voltage reduction tests scheduled by the IESO were held on February 7, 2012.
  • Province-wide implementation of a five per cent voltage reduction reduces demand for electricity in the province by about 500 megawatts (MW).


PowerStream is a community-owned energy services company providing power and related solutions to more than 360,000 customers residing or owning a business in communities located immediately north of Toronto and in Central Ontario. It is jointly owned by the Cities of Barrie, Markham and Vaughan.


CONTACT: Eric Fagen, Director, Corporate Communications Media Line (24/7): 905-532-4400 Email: Website:

Source: Powerstream