Technical data

5-4

Site Preparation and Installation

A second type of UPS is called a “standby” UPS, or SPS. This device

switches to a battery system if power fails. SPS units usually lack

protective circuitry and power conditioning capability; as a result,

they are more susceptible to input power fluctuations than no-

break/online UPS units. If you opt for an SPS, be sure to get one

that has a switchover time of 5 milliseconds or less. Some SPS units

provide enough power to shut the system down in the event of a

power failure; others furnish enough for the system to continue

operating for a specified period of time during the power failure.

The UPS or SPS must have receptacles to furnish power to both the

processor enclosure and the console terminal.

Circuit Breakers and Receptacles

Circuit breakers furnishing power to any portion of the system

must be of the correct size to protect the equipment. Receptacles

must be wired according to the three-wire power distribution

scheme (line, neutral, and ground).

All power receptacles servicing any equipment that is directly

cable-connected to the system (modem/terminal server and fiber

optic connections excluded) must have a single, common

grounding point. The ground wire must be at true ground potential

with a resistance (measured at the power panel bus) of five ohms or

less between the bus bar and earth. The ground wire must be of the

“third wire” type, not conduit ground.

Electro-Static Discharge

Motorola computer systems are designed to withstand up to 5 kV

(Kilovolts) of ESD with no observable effect, up to 12 kV without

system interference, and up to 24 kV without damage to the

equipment.

1. Several times the ESD potential that you are likely to accumulate by walking across a carpeted floor.