Galaxy PW™ UPS 100 to 225kVA

1.6Electrical Parameters for Selecting Protective Devices1.6.1Normal AC Source

The parameters given in Table 1-1 can be used to determine the required rating of the upstream protective circuit breaker on the normal AC input for one single-UPS or parallel-UPS unit.

Normal and Bypass AC Input:

 

number of conductors

3 phases

rated voltage and tolerances

480 V ± 10% (adjustable to ± 15%)

rated frequency and tolerances

60 Hz / ± 10%

IMPORTANT

It is essential to choose the type of circuit breaker according to its breaking

 

capacity and the prospective short-circuit current at its place of installation.

 

This choice must also be made so as to protect the static-switch semicon-

 

ductors with respect to the maximum permissible currents and ensure

 

discrimination between the UPS output fuses and the downstream

 

protection devices.

 

 

Table 1-1: Electrical Parameters for Normal AC Source.

Electrical parameters for the normal AC source

rated

current normal AC source

 

 

 

UPS

rated current In for unit:

 

for 25%

for 50%

output

with battery at start

without battery (2)

overload (3)

overload (3)

in kVA

of charge cycle (1)

 

 

 

100

166

159

199

239

130

214

205

256

308

150

245

236

295

354

180

295

283

354

425

200

328

316

395

474

225

332

320

400

480

(1)The rated normal AC source currents (In) have been determined for a rated phase-to-phase voltage of 480 V, a battery with a 10 minute backup time at the beginning of its charge (412 x 1, 2 = 494 Volts) and full rated load with a power factor of 0.9.

(2)The rated normal AC source currents (In) have been determined for float charging voltage and full rated load with a power factor of 0.9

(3)The normal AC source currents given for an overload of 25% or 50% are maximum values. They have been determined for a battery with float charging voltage and a load power factor of 0.9. When choosing the circuit breaker rating, use the "rated current" column and check that the circuit breaker tripping curves are compatible with the values in the overload columns.

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