Section 9 Transformers, Vaults & Substations
9.1 General Comments
When large concentrated loads or long distances are encountered, it is frequently necessary to install transformers on or in the Customer’s property. In such cases, high voltage conductors are taken directly to the transformer. Whether transformers are to be installed outside, on, or in the Customer’s property, a suitable location must be provided by the Customer. The Customer shall consult the Department regarding the location, size, and construction of the facilities during the design and planning phase
In the interest of public safety, it is imperative that all transformers be readily accessible to the Department at any time of the day or night. In all but the most unusual cases, the Customer must equip each door (or other barrier) between the transformer and the nearest public access with locks that can be opened by the Department. These locks will be provided by the Department and installed by the Customer.
For ready access to unenclosed pad mount transformers, a minimum clearance of three feet from the side and back edges of the pad and twelve feet from the front of the transformer must be maintained at all times.
The Department will not energize its facilities until the installation is made in accordance with manufacturer recommendations, engineering standards, is approved by authorities having jurisdiction, and is acceptable to the Department.
9.2 Fences, Screen Walls, Decorative Walls
The Department will not construct, reimburse the Customer, or accept ownership and maintenance responsibility of any fences, screen walls, or decorative walls around pad mount transformer installations or vaults. Prior written approval must be obtained from the Department before the Customer constructs such walls or fences. Adequate space and means of ingress and egress (such as wide removable panels) must be provided to operate, maintain, remove and replace transformer, metering or other equipment located behind the fence or wall.
9.3 Types of Transformer Installations
The Department provides electric service from one of the following general transformer installations:
| (1) Pole mounted transformers, one or cluster of two or three transformers |
| (2) Pad mount transformers, open |
9.4 Pad mount Transformers
Pad mount transformers are generally provided, owned and maintained by the Department for underground service to residential subdivisions, mobile home parks, shopping centers, and commercial and industrial customers. Consult the Department for requirements and availability in totally underground systems.
For pad-mount transformers in non-residential applications, the Customer will provide the service lines to the secondary connectors. These lines must be copper and must not be larger than 500 MCM in size.
9.5 Termination of Secondary Conductors to Transformers For Non-Residential Services
Terminals for secondary conductors shall be installed as provided in Section 8.11, Termination of Conductors.
The phasing, sizing and proper length of conductors is the sole responsibility of the Customer. The Customer shall also be responsible for properly marking the phases. Connection of the terminals to the connectors of the transformer will generally be made by the Department.