Skamania PUD metering equipment standards for single-family residential structures or commercial services (400amp or less) are based upon the single-phase service ratings. All meter bases that are installed shall meet the following general requirements:
- Rated for exterior use and rain tight.
- Ringed meter base cover (ringless will not be accepted).
- Underwriters Laboratories (UL) rated.
- Have unused openings in the enclosure tightly sealed from the inside of the base.
- Installed level, plumb, and fastened securely to a rigid structure.
- Secondary Surge Arrestor Meter Sockets will not be accepted.
- Meter Mounted Transfer Switches will not be accepted.
- If installing a Combination Service Entrance Device (CSED), the minimum distance between the center of meter socket to edge of meter base socket enclosure must be at least 7 inches, anything less will require customer to install new meter base and have it re-inspected by L&I at customer cost.
Note: Specific metering requirements for 200 amp and 400 amp services are listed below. It is the customer’s responsibility to install the appropriate meter base. The PUD cannot give guidance, any questions about the meter base need to be addressed by an electrician or the Washington Department of Labor & Industries.
200-Amp Service
The 120/240-volt 200-amp service is the most common service installed by Skamania County PUD. Typically, the size of service is installed to home with a living area of less than 2,400 square-feet. Depending upon the type of appliances, heating and cooling system or other equipment (hot tub, jetted tub, car charger, etc.) being installed, a larger service may be necessary. It is the customer’s responsibility to determine and notify Skamania County PUD of the electrical requirements based on connected load.
In addition to the meter base requirements mentioned earlier, meter bases for 200-amp underground services shall:
- Be rated for 120/240 volts and 200 amps.
- Contain 4-meter jaws and a connection point for the neutral conductor.
- Accept 3-inch, PVC, conduit.
- Have lugs (electrical connectors) that are marked to accept 4/0 aluminum conductors.
Note: Do not route service conductor through the center knockout located on the bottom of the meter base.
400-Amp Service
The meter base required for a 120/240-volt 400-amp service is called a class 320-meter base. It is larger than the 200-amp meter base, but it is still a self-contained metering system. It can be installed on residences where the continuous current rating is 320 amp or less. In addition to the meter base requirements mentioned earlier, meter bases for Class 320 for 400-amp services require:
- Rating for 120/240 volts and 320 amps continuous current.
- 4-meter jaws and 1 connection point for the neutral conductor.
- A Class 320 manual block bypass.
- Lever bypass devices are not allowed.
Note: Do not route service conductor through the center knockout located on the bottom of the meter base. Any structure needing more than 320 amps of continuous current, a CT metered service will be required.
Self-Contained Commercial Meter Bases
Self-Contained, or direct connect meters, carry full load current and connect directly across full line voltage. A safety socket or bypass meter socket is required for all self-contained commercial meter systems.
A safety socket allows the utility to maintain self-contained metering systems without interrupting service to the commercial customer. The meter terminals are de-energized allowing utility personnel to safely perform routing meter maintenance. A safety socket style meter base is required for the following services:
- All commercial three-phase services.
- Single-phase 240/480 volt services (municipal lighting only).
- Temporary commercial services that are three-phase or 480 volt.
- Single-phase services with metering installed inside a meter enclosure.
Manual bypass meter sockets also allow maintenance of self-contained metering equipment while maintaining service to the customer. Meter terminals are not de-energized when by-passed. This style of meter base is acceptable for lower voltage, single-phase commercial services only. A manual bypass meter socket is required for:
- All single-phase commercial services 240 volts or less.
- 120/208 volt single-phase commercial network meters.
The following commercial metering exceptions do not require a manual bypass or safety socket style meter base:
- Single-phase commercial temporary services (120/240 or 120/208 voltages).
- House meter sockets included in a factory-built multifamily residential meter pack.
Grounding & Bonding Requirements
Grounding and bonding is critical for safety and electrical reliability. The customer is responsible to ensure that the electrical wiring and service equipment is grounded and bonded in accordance with the NEC and the local governing office.