User's Guide Power Supply 9150

Introduction

Powerware

9150 User’s Guide www.powerware.com

UPS Model and Battery Configurations

There are two important considerations whenselecting the UPS model

and battery configuration to properly safeguard your equipment:

The UPS output power rating (VA) should be specified according to

the total power demand of the equipment to be protected. Some

margin should be allowed for potential expansion of the protected

system,and for possible inaccuracy in calculating or measuring the

actual power requirement.

The battery should be sized according to the desired backup time.

The backup time is longer if the load is less than the nominal power

rating of the UPS.

Load Requirements

Determine the total load requirements, in volt-amperes (VA), of the

equipment to be protected by the UPS. The UPS load should not exceed

the UPS rating. To determine the total load requirements:

1. Obtain the load ratings from either the nameplate or operator’s

manual of the equipment to be protected by the UPS. The

ratings are listed in either watts (W), amperes or amperes max

(A), or volt-amperes.

2. If the rating is in watts, multiply by 1.4 to obtain the VA

requirement (this is the typical relationship between watts and

volt-ampere ratings in most computing equipment).

If the rating is in amperes or amperes max, multiply by the

input voltage to obtain the VA requirement.

3. Add all of the resultant VA ratings together to obtain the total

load requirements of the equipment to be protected (see

Figure 2).

3 COMPUTERS 3 MONITORS EXTERNAL

MODEM

3 x 300 WATTS X 1.4 = 1260 VA 3x2AMPSx240V = 1440 VA 50 VA

1260 VA + 1440 VA + 50 VA = 2750 VA (Total Load Requirements)

300 WATTS

EACH

2AMPS

EACH 50 VA

Figure 2. Volt-Amperes Calculation Example