Challenge: When the construction contractor performed manhole/duct verification, they found the duct system had collapsed between 2 manholes.
Result: Verification allowed ComEd to send a crew to dig up the duct system and make the necessary repairs so that the new cable could be installed, allowing construction to stay on schedule.
This was the first project of this type for Milhouse. It involved designing underground distribution cable replacement and 2 different substation upgrades in order to accommodate Jesse Brown VA hospital’s new natural gas synchronous generator, which allows the hospital to feed power back into ComEd’s 13kV system.
The scope of work included:
- Replacing approximately 1,900 of 500CU PLJ cable with 650CU EXFSJ cable in an existing manhole/duct system
- Design to replace the electromechanical relaying with a microprocessor package consisting of a SEL-351S and SEL-751
- Adding 2 voltage sensors on the line side of the breaker to enable sync check
- Designing the installation of 3-12kV PT’s at the customer substation with a broken delta secondary to provide voltage for ground fault monitoring
Milhouse was responsible for:
- Construction drawings required to complete the scope of work
- Design in the client’s GIS system
- Demarcation drawings for the customer
- Subcontracting a qualified contractor to perform duct verification
- Ordering the material through the client’s proprietary system
- All permitting necessary to complete the construction
