Voltage Reduction Test Scheduled for Tuesday, July 18, 2023 

The Independent Electricity System Operator (IESO) will conduct a routine voltage reduction test on Tuesday, July 18, 2023, as part of mandatory testing of its emergency operating procedures. This province-wide test will have minimal noticeable impact on the public at large.  

The test will consist of two reductions in voltage: 

  • A three per cent voltage reduction will occur from 9:00 – 10:00 EST 
  • A five per cent reduction from 13:00 – 14:00 EST.  

These tests are normally conducted every 18 months. If you did not notice any impact on your equipment during past tests, you should not notice it during this test.  

Ensuring a reliable grid 

Voltage reduction is one tool that the IESO could use to help maintain the reliability of Ontario’s power system in an emergency situation. Voltage reduction tests have three key purposes:  

1. To determine how much power can be reduced through the two levels of reduction.  

2. To identify equipment problems so they can be addressed.  

3. To help keep IESO and market participant staff familiar with procedures and identify any deficiencies in the procedures that may need correction.  

For more information 

The IESO is responsible for managing Ontario’s bulk electricity power system and operating the wholesale market. More information about their services can be found at www.ieso.ca.  

Additional information about the voltage reduction test can be found on the IESO’s website at https://www.ieso.ca/en/Sector-Participants/System-Reliability/Voltage-Reductions 

Customers with questions about the test can contact our Customer Care team by phone at 226-896-1010 or by email at communications@enovapower.com 

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