Skamania PUD metering equipment standards for single-family residential structures are based upon the single-phase service ratings. All residential meter bases that are installed shall meet the following general requirements:
- Rated for exterior use and rain tight.
- 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.
Note: Specific metering requirement 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 address by an electrician or the Washington Department of Labor and Industries.
200 - Amp Service
The 120/240-volt 200-amp service is the most common residential 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 200amp 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 320meter 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.
Residential Current Transformer (CT) Metering
Services greater than 400 amp (320 amps continuous current) require CT metering. This type of metering system requires prior approval from a Skamania County PUD Representative and requires an additional construction charge. This service requires a different meter base and equipment. All underground CT metering equipment will be installed by Skamania County PUD and be located at the transformer.
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.
