The line-to-line unbalanced output capability of the UPS is limited only by the full load per phase current values for AC output to critical load shown inTable 2-4.The recommended line-to- line load unbalance is 50% or less.

Source protection for the AC input to bypass should be treated as if supplying a 550 kVA three- phase transformer, to allow for inrush current. Bypass input wiring and bypass input breaker rating should be treated as if supplying a 550 kVA load, regardless of the rating of the UPS.

Bypass and output overcurrent protection and bypass and output disconnect switches are to be provided by the user.Table 2-8 lists the recommended rating for bypass and output circuit breakers satisfying the criteria for both.

 

 

Circuit breaker rating

 

 

UPS model

Load rating

 

400 V

 

Bypass

 

Output

 

 

 

9395-2*225

100% rated

800 A

 

160 A (B-type breaker)

9395-450

100% rated

800 A

 

160 A (B-type breaker)

9395-2*275

100% rated

1000 A

 

200 A (B-type breaker)

9395-550

100% rated

1000 A

 

200 A (B-type breaker)

Table 2-8. Recommended bypass and output circuit breaker ratings

There is no DC disconnect device within the UPS. A battery disconnect switch is recommended, and may be required by local codes when batteries are remotely located.The battery disconnect switch should be installed between the battery and the UPS.

External DC input overcurrent protection and disconnect switch for the remote battery location is to be provided by the user.Table 2-9 lists the maximum rating for continuous-duty rated circuit breakers satisfying the criteria for both.

UPS model

 

Input rating

 

600 V

 

 

9395-2*275

 

2*700 A (630 A, depends on end voltage)

9395-550

 

1400 A (1250 A, depends on end voltage)

Table 2-9. Recommended DC input circuit breaker ratings

 

Battery voltage is computed at 2 volts per cell. Rated battery current is computed at 2 volts per cell.The battery wiring used between the battery and the UPS should not allow a voltage drop of more than 1% of nominal DC voltage at rated battery current. If the conductors used for DC input from the battery cabinets to the UPS are those provided by the UPS manufacturer, and the UPS and battery cabinets are manufactured by the same supplier, then it is acceptable if they do not meet the noted minimum conductor sizes.

2.2.3 UPS system interface wiring preparation

Control wiring for features and options should be connected at the customer interface terminal blocks located inside the UPS.

WARNING

Do not directly connect relay contacts to the mains related circuits. Reinforced insulation to the mains is required.

1027574

UPS 450 - 550 kVA (2x225 - 2x275 kVA)

17

Revision B

User’s and Installation Guide