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Equipment Inspections

Graphic showing needed distance between pad-mounted equipment and obstacles.


Ameren Missouri is complying with reliability rules issued by the Missouri Public Service Commission (MoPSC) regarding the inspection of underground facilities. 

Under the rules, utilities must visually inspect underground transformers and other pad-mounted equipment once every four years, and open this equipment and perform detailed inspections once every eight years. 

How this impacts you - the property owner 

If you receive a letter from Ameren Missouri indicating your pad-mounted equipment will be inspected, please note that some action may be required on your part. We will follow a standard procedure for completing this work: 

  • Within a few weeks of the date of the letter, Ameren Missouri representatives will be in your area to inspect our underground facilities. Please prepare for their visit. Check the area around the pad-mounted equipment. Assess what you need to remove to obtain proper clearance. See the illustration above. 
  • Keep the area clear - within 10 feet of the equipment access door, and within 30 inches on all other sides of the pad-mounted equipment. See examples of obstructions

Note: These clearances are required for the proper maintenance and operation of Ameren Missouri's equipment. Inability to maintain or operate our equipment can lead to a lengthy outage for property owners and their neighbors. 

Please call 811 before you dig so underground utilities can be marked and identified. 

Pad-Mounted Equipment Inspection Types 

Ameren Missouri representatives will complete the inspection or equipment testing. If they find any obstructions in the required clearance areas, they may not be able to complete the inspection or testing process. As the property owner, you may be contacted by an Ameren employee to discuss options to remove the obstruction, which will allow us to complete our inspection. 
Minor vegetation, bushes and shrubs may be trimmed or removed by Ameren Missouri representatives, in order to complete the inspection, or for operating and maintenance purposes. Ameren Missouri personnel conduct two types of inspections:  
Patrol Inspections 
Completed once every four years. 
Visual inspection of equipment. 
Designed to identify problems or hazards. 
Detailed Inspections 
Completed once every eight years. 
Careful examination of transformer structure. 
Transformer is opened, and its condition rated and recorded. 
Visual and thorough use of routine diagnostic testing, if needed.  

Note: Some vegetation, where trimming is required to complete our inspection, may be left for homeowners disposal. For more information, call 800.552.7583. 

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