MAP1130 PPS Fan Normal and Failure Modes

The PPS fans have multiple operation modes for normal as well as failure conditions.

MAP1130 Section-1

Procedure

The operation of the PPS fans is monitored and controlled by the microcode running in the PPS sequence module. The fan speeds are controlled individually and vary for normal operation. If an error condition occurs, a serviceable event is created and reported.
The PPS fans are controlled in 2 ways:
  • The speed of the fans is controlled in steps depending on the internal temperature sensors in the PPS modules and other conditions.
  • There are certain defined fan speed combinations for normal as well as error conditions. These combinations are shown in Table 1 and Table 2.
There are four fan speeds used:
  • Stopped (0 rpm)
  • Low (1860 rpm)
  • Medium (2820 rpm)
  • High (3800 rpm)
Table 1. Normal System Operation or System Standby Mode
Operating/Failure Condition Top PPS Fan Center PPS Fan Bottom PPS Fan
Normal Mode Low Low Low
Top PPS Fan failed Failed High High
Center PPS Fan failed High Failed High
Bottom PPS Fan failed High High Failed
PPS to PPS Communication Failure Medium Medium Medium
Battery charging in phase 1 Medium Medium Medium
On Battery Mode (Booster not installed) Stopped Stopped Stopped
On Battery Mode (Booster installed) Stopped Stopped Stopped

During PPS standby or fenced mode (208VDC and 5V/12V outputs are off), only the bottom and the center fans will operate.

Table 2. PPS Fenced Mode / PPS Standby Mode
Operating/Failure Condition Top PPS Fan Center PPS Fan Bottom PPS Fan
Normal Mode Stopped Low Low
Center PPS Fan failed Stopped Failed High
Bottom PPS Fan failed Stopped High Failed
PPS to PPS Communication Failure Stopped Medium Medium