- directional coupling
- directional relay
- directional signal
- disassemble
- disc capacitor
- disc constant
- disc recorder
- discharge capacitor
- discharge circuit
- discharge device
- discharge path
- discharge switch
- discharge voltage
- discharger
- disconnect plug
- disconnecting switch
- disconnector
- discrete capacitor
- discrete resistor
- discriminator
- disjointing
- disk capacitor
- disk insulator
- displacement factor
- disruptive current
- distance protection
- distortion
- distributed winding
- discharge
- discharge resistor
- discharging
- disconnect
- disconnect link
- disconnectable
- disconnecting jaw
- disconnection switch
- disconnector switch
- discriminating relay
- dispatching room
- dispenser cathode
- disruptive voltage
- distributed capacitance
- distributed network
- distributing busbar
- distribution board
- distribution order
- distribution substation
- distribution system
- distributor cap
- dividing box
- division
- doctor
- disruptive
- distributed circuit
- distribution box
- distribution cable
- distribution network
- distribution pillar
- diversion requirement
- diversity factor
- disk
- disk winding
- displacement current
- disruptive test
- distributed inductance
- distribution bus
- distribution cabinet
- disturbance
- disturbance test
- divided commutator
- dot sequential
- domain theory
- donor impurity
- door bell
- door switch
- doorknob cell
- double bridge
- double conductor
- double contact
- double insulator
- double ionization
- drain bias
- drain connection
- drain contact
- drain terminal
- drained cable
- drive coil
- driver
- drum stand
- drum switch
- drum winding
- dry circuit
- dry connector
- double cable
- double commutator
- double seizure
- down guy
- DPST relay
- drain current
- drainage pump