Special trade contractors primarily engaged in electrical work at the site. The construction of transmission lines is classified in Industry 1623, and electrical work carried on in repair shops is classified in Services, Industry Group 762. Establishments primarily engaged in monitoring of burglar and fire alarms with incidental installation are classified in Services, Industry 7382.
- Burglar alarm installation-contractors
- Cable splicing, electrical-contractors
- Cable television hookup-contractors
- Communications equipment installation-contractors
- Electrical repair at site of construction-contractors
- Electrical work-contractors
- Electronic control system installation-contractors
- Fire alarm installation-contractors
- Highway lighting and electrical signal construction-contractors
- Intercommunications equipment installation-contractors
- Sound equipment installation-contractors
- Telecommunications equipment installation-contractors
- Telephone and telephone equipment installation-contractors