For more information about temporary capacity increases, see Chapter 8, “System upgrades” on page 281. 

## 2.8 Power and cooling 

The z14 ZR1 power and cooling system is a change from previous systems because the system is packaged in an industry standard 19-inch rack form factor for all the internal system elements. The power subsystem is based on Power Distribution Units (PDUs) that are mounted at the rear of the system in pairs. The new PSCN structure uses industry standard Ethernet TOR switches that replace the previous IBM System Control Hubs (SCHs). 

## 2.8.1 Considerations 

The IBM Z systems operate with redundant power infrastructure. The z14 ZR1 is designed with a new power infrastructure that is based on intelligent (PDUs that are mounted vertically on the rear side of the 19-inch rack) and Power Supply Units for the internal components. The PDUs are single phase, 200 - 240 VAC and are controlled by using an Ethernet port. 

The power supply units convert the AC power to DC power that is used as input for the Points of Load (POLs) in the CPC drawer and the PCIe+ I/O drawers. 

The power requirements depend on the number of PU SCMs that is installed in the CPC drawer and number of PCIe+ I/O drawers (1 - 4) and I/O features that are installed in the PCIe+ I/O drawers. 

The power subsystem in a z14 ZR1 includes the following main characteristics: 

GLYPH<SM590000> Two or four single phase PDUs (200 - 240 VAC, 50/60 Hz), each with a 30A power cord. 

GLYPH<SM590000> Maximum supported rack power is 9600W. 

GLYPH<SM590000> No High-Voltage DC power option. 

GLYPH<SM590000> No three-phase power, no 480 VAC. 

GLYPH<SM590000> No Emergency Power Off (EPO) switch. 

GLYPH<SM590000> No balanced power option or plan ahead power cables (installation of extar PDUs and PCIe+ I/O drawers is nondisruptive if enough PCIe fanouts are available in the CPC drawer). 

GLYPH<SM590000> No Internal Battery Feature (IBF). The standard data center power protection (uninterruptible power supply based) can be used. 

GLYPH<SM590000> If the 16U Reserved feature (FC 0617) is installed, the total power consumption for equipment that is installed under this feature is limited to 3400W. For more information, see Appendix G, “16U Reserved feature” on page 465. 

The following previous features are not available on the ZR1: 

GLYPH<SM590000> Internal Battery Feature (IBF) 

GLYPH<SM590000> 480V AC 

GLYPH<SM590000> High-Voltage DC Power 

GLYPH<SM590000> Balanced Power, no plan ahead power cords 

GLYPH<SM590000> external EPO (Emergency Power Off) switch 

GLYPH<SM590000> Three-Phase Power 

GLYPH<SM590000> Single SE Display and keyboard, which includes a KVM switch 

