The Service
Entrance
10
165
Objectives
Information in this chapter will enable you to:
• List the components of the service entrance.
• List service drop clearances specifi ed in the
NEC.
• List eight basic guidelines when locating a
residential service entrance.
• Calculate the size of service entrance needed
based on the power needs of the dwelling.
• Select proper conductors and components
for the service entrance.
• Size and install conductors between the
meter socket, main disconnect, and service
panel.
• Provide proper grounding for a service
entrance.
• Explain the purpose of a step-down trans-
former and indicate where it is used.
Technical Terms
Drip loop
Insulator
Meter
Meter enclosure
Service head
Service lateral
Meter socket
Service drop
Service drop mast
Service entrance
Temporary wiring
Transformer rule
The service entrance includes all the wires,
devices, and fi ttings that carry electricity
from the power company’s transformer to the
consumer. All electrical energy supplied to
power-consuming devices in the building must
fi rst pass through the service entrance equip-
ment. The service components protect, meter,
and distribute the power to the branch circuits.
Service Entrance
Components
The service entrance consists of the following
electrical equipment and parts:
• Wires from the utility pole or transformer to
the dwelling service point
• Service entrance conductors
• Meter socket, pan, or enclosure
service entrance: All of the wires, devices, and fi ttings
that carry electricity from the power company’s trans-
former to the consumer.