China offered to help restore the electrical system. The voltage chosen for any electrical system is a compromise. Emergency extension can be accomplished pneumatically in case of hydraulic or electrical system failure. The following would be appropriate for the design of a moderate to large electrical system. The heating elements activate one at a time to avoid overloading the electrical system. There were also new improvements to the powertrain and electrical system for 2003. The clock runs on a turret clock electrical system. Two fires and a complete failure of the electrical system occurred in the air. Pilot light solutions work independently of the electrical system. There was also a loss of in transmission through the electrical system. The electrical system became 12 volt. The electrical system was 28 volts D.C. The Welkin required a sophisticated electrical system. An overhead catenary electrical system is specified. In the 1990s a 42V electrical system standard was proposed.