21-1
CHAPTER
21
Sensor Unit Replacement
This chapter explains the replacement procedure for the sensor unit (SNSU). It covers the
following:
■ Section 21.1, “Overview of the SNSU” on page 21-1
■ Section 21.2, “Cold Replacement” on page 21-4
As a replacement method for the SNSU, only the cold replacement method can be used. For
the definition of the replacement method, see Section 4.1, “Types of Replacement
Procedures” on page 4-2.
21.1 Overview of the SNSU
This section provides an overview of the SNSU and describes its mounting locations.
The sensor unit monitors the temperature and humidity of air drawn in by the server. The
sensor unit consists of only a detecting element, and the controller block is built in to the
operator panel. Active maintenance cannot be performed on the SNSU.
FIGURE 21-1, FIGURE 21-2, and FIGURE 21-3 show the mounting locations of the SNSUs of
M8000 server, M9000 server (base cabinet), and the base cabinet of M9000 server with the
expansion cabinet respectively.