NEC 27U, User Manual

Page: 34 / 72

3-6 Planning Your System Rack Configuration
Configuration Guidelines
When you configure a system, you should check your configuration to ensure
compliance with the following guidelines:
1. To improve rack stability when servicing system components, mount heavier
items such as servers in the bottom of the rack. If your rack is a stand-alone
unit and the rack is more than 75% filled with components, consider
installing the optional side stabilizer kit.
2. Each Model 42U Rack can contain up to 42U of components (1U is equal to
1.75 inches). Models 36U and 27U contain up to 36U and 27U of
components, respectively.
3. The maximum Volt/Amps available from a single UPS is 3000VA (2250W).
4. The maximum Volt/Amps available from a single PDU is 2880VA.
5. The UPS should always be installed in the bottom of the rack.
6.
The UPS and its associated PowerChute
®
plus software can only support
three servers per UPS, without purchasing an additional interface expander
module and additional cables.
7. If power distribution is provided by a PDU, the PDU is normally installed in
the bottom of the rack. However, when rack space is at a premium, you can
install the PDU directly behind the keyboard tray or the monitor tray.
8. The keyboard can be no more than 5U from the BSU unless a concentrator
or extension cables are purchased.
9. If you are configuring the keyboard for use in a standing position, the
recommended height is 18 to 20 U.
The System Rack Configuration Worksheet, Table 3-3, may be used to calculate
the space requirements for components you plan on installing into the rack.