H7237 Battery PIU

This manual is an installation guide for Digital service engineers and self-maintenance customers, detailing the process of installing the H7237 Battery Plug-In Unit (PIU) and its battery blocks into DEC 7000, VAX 7000, and AlphaServer 8400 systems. The H7237 PIU serves as an uninterruptible power source (UPS), housing one to three battery blocks (each containing four batteries) to provide a minimum of 8 minutes of backup power for CPU, memory, I/O, and disk subsystems. It specifically supports H7263-AA or -AB BBU-capable power regulators.

The document is organized into three main chapters:

1. Preparation: Describes the H7237 PIU, its specifications, configuration rules, and the necessary steps to prepare the installation area, kit, and tools, including a mandatory system shutdown.
2. Installation: Provides step-by-step instructions covering:
   • Removing cabinet airflow plates.
   • Disassembling and installing the PIU enclosure (noting its significant weight, 110 lbs without batteries).
   • For AlphaServer 8400 systems, replacing non-BBU-capable H7263-AC or -AD regulators with BBU-capable H7263-AA or -AB models (emphasizing that regulators are heavy and have heated surfaces).
   • Attaching battery and sensor cables to the DC distribution box and fuse blocks, with a critical warning to observe correct polarity to prevent severe system damage.
   • Installing and cabling Regulator A, B, and C batteries (each weighing 25 lbs), including warnings about electric shock, short circuits, and electrolyte leaks.
   • Replacing fuse covers and attaching PIU doors, and fully engaging the power regulators.
3. Acceptance and Troubleshooting: Details how to restore system power, check self-test results, and use set power and show power commands to configure and monitor the power system status.