Customer News
July 7, 2026
IESO Scheduled to Carry Out Routine Voltage Reduction Tests on July 23, 2026
The Independent Electricity System Operator (IESO) has announced that it will carry out routine voltage reduction tests on Thursday, July 23, as part of mandatory testing of the IESO's emergency operating measures. The test is an important tool for ensuring the reliability of Ontario's electricity grid.
The test schedule is as follows:
- 3% reduction between 9:00 AM and 10:00 AM
- 5% reduction between 1:00 PM and 2:00 PM
Voltage reduction tests have three key purposes:
- To determine how much power can be reduced through the two levels of reduction.
- To identify equipment problems so they can be addressed.
- To help keep IESO and market participant staff familiar with procedures to execute voltage reductions and identify any deficiencies in the procedures that may need to be corrected.
Impact on Customers
The voltage reduction tests are expected to have minimal or no noticeable impact on the public, as the voltages are still expected to be within established industry standards for electrical equipment used by residential, commercial, and industrial consumers.