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What is Stray Voltage?

Stray voltage is a small electrical potential between two conductive surfaces like metal stabling, milk pipelines, water bowls and floor surfaces. It usually presents no harm and is the byproduct of the normal delivery and use of electricity. However, if the voltage level is high enough, it may affect livestock behaviour and health.

How It Works

Hydro One’s Farm Rapid Response Team works with farmers, following a step-by-step Stray Voltage Investigation to address and resolve concerns about stray voltage.

Here’s what you can expect:

  • Step 1

  • Schedule an Assessment of your Farm
  • Submit a form to begin an investigation. After we receive your completed form we will call you within five business days to arrange a site visit.

  • Step 2

  • FIRST Site Visit
  • We’ll meet with you at your property to perform pre-test inspections, conduct a site layout, carry out an animal contact test and install a farm stray voltage recording device. An extra visit may be required if underground utility lines need to be located.

  • Step 3

  • Second Site Visit
  • Two to three business days later, we’ll remove the recording device and analyze the recorded data.

  • Step 4

  • DATA Analysis
  • The Ontario Energy Board (OEB) has specified a threshold of 1.0 volt maximum animal contact voltage and 2 milliamps maximum animal contact current. If the stray voltage is below the threshold, the investigation will conclude.

  • Step 5

  • Further Investigation
  • If the stray voltage measured is above the threshold, we’ll do further testing to determine whether corrective measures are needed.

  • Step 6

  • Final Site Visit
  • If corrective measures are implemented by us, we’ll return to your property to conduct final testing.

  • Step 7

  • Upon completion of all investigation activities and remediation work (if required), we’ll send you an investigation report.

Hiring an Electrical Contractor

You may also hire an electrical contractor to help identify on-farm sources of stray voltage. 

For more information

For additional information on the effects of stray voltage on livestock, refer to these additional resources:

Hydro One is here to help. And yes, that goes for cows too.

We are accountable for all aspects of our business. That’s why our Farm Rapid Response Team is ready to help test, mitigate or allay concerns about stray voltage. Complete the form online to get started.

Contact Us

Farm Rapid Response Team

Tel: 1-888-405-3778


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