861-A,B,C Power Controller Maintenance Manual

This document is a Maintenance Manual for the Digital Equipment Corporation 861-A,B,C Power Controller series.

Key information provided:

• Purpose: It details the installation, operation, and maintenance of the 861 power controllers, which are designed to control and distribute power to data processing equipment.
• Versions: Three versions (861-A, B, C) are available, differing in input voltage and phase configurations (e.g., 90-135V two-phase, 180-270V single-phase).
• Functions: The controllers manage large amounts of power with small control signals, distribute primary power, filter power, and automatically remove power in case of overload or overtemperature.
• Physical Characteristics: They are rack-mountable (19-inch standard) and include a main circuit breaker, pilot lamps, a LOCAL/OFF/REMOTE control switch, and multiple switched and unswitched power outlets.
• Control Mechanisms: Power to switched outlets can be controlled locally or remotely via a signal bus with "Power Request" and "Emergency Shutdown" lines. An overtemperature switch automatically disables switched outlets if the internal temperature exceeds a safe limit.
• Content: The manual includes detailed specifications (electrical, mechanical, environmental), instructions for installation (site considerations, cabling, grounding, initial operation), operational procedures, a theory of operation for the various circuits (line filter, relay, pilot control board, spike suppression), and comprehensive maintenance procedures, including preventive measures and a troubleshooting flow diagram for common issues.