HP A9834-9001B - Manual (Page 71)

Chapter 2
System Specifications
Environmental Requirements
71
b. These numbers are valid only for the specific
configurations shown. Any upgrades may require a
change to the breaker size. A 5-wire source utilizes a
4-pole breaker, and a 4-wire source utilizes a 3-pole
breaker. The protective earth (PE) ground wire is not
switched.