User`s guide

Power and Cooling Systems
4.1.1 Input Power
The input power is five-wire (three-phase AC, neutral, and ground).
208V 60 Hz AC enters the H405-E AC power controller. 380V 50 Hz AC
inputs the H405-F AC power controller and then enters the high-voltage
autotransformer, which reduces the voltage to 208.
The H405 AC power controllers suppress conducted emissions. The AC
power controller has a contactor that closes when the control panel upper
key switch is in any position except "0," allowing AC power to the H7206-
B, and opens if the cabinet’s temperature sensor detects an excessive
temperature.
4.1.2 H7206-B Power and Logic Unit
The H7206-B:
• Rectifies the three-phase power into 300V DC for the DC-to-DC power
regulators
• Develops regulated +14V DC for both internal use and the DC-to-DC
power regulators
• Develops 110 watts of 24V DC for the cooling system blowers and its
own internal fan
• Controls the interface between power regulators
• Controls the interface between the power regulators and the rest of
the system
The nine LEDs in the upper right corner of the H7206-B are explained
in Table 4–1. The green +14V bias LED lights to indicate when the bias
supply on the fan/power module is working.
Table 4–1 H7206-B LEDs
LED Color Meaning
9 Red Fault (airflow, interlock, overtemperature)
8 Red XMI-1 module in XMI-2 card cage
7 Red H7214 or H7242 installed incorrectly
6 Red VAXBI—H7214 fault
5 Red VAXBI—H7215 fault
4 Red XMI—H7242 fault
3 Red XMI—H7214 fault
2 Red XMI—H7215 fault
1 Green +14V logic bias is okay
4–2