Liebert 610 manual Load on maintenance bypass two breakers

Operation

3.3.9Maintenance Bypass

Maintenance Bypass switchgear allows you to totally isolate the UPS from all power sources, while you maintain power to the critical load.

Your installation may have a two-breaker or three-breaker maintenance bypass or none at all. The main difference between a two-breaker and three-breaker maintenance bypass is the location of the Bypass Input Breaker (BIB).

Another option that may be present at your site is an alternate power source (generator) and an auto- matic transfer switch (ATS).

Note that to totally isolate the UPS system from all power sources, the Main Input switchgear and battery circuit breakers must also be opened.

! CAUTION

Instructions for operating the Maintenance Bypass circuit breakers are on the Maintenance Bypass cabinet. Make sure you understand the proper sequence before operating any circuit breaker. Operating a Maintenance Bypass circuit breaker out of sequence could cut off power to the critical load.

Figure 50 Load on maintenance bypass (two breakers)

TWO BREAKER MAINTENANCE BYPASS SWITCHBOARD

MBFB MBB

Critical

Load

MIB

AC Output

	UPS MODULE
	Static
BIB	Switch
	Disconnects

Static

Bypass

Switch

Bypass CB

CONTROL POWER

RIB

Controls

Rectifier/

Inverter

INPUT

CB

MAIN INPUT

SWITCHGEAR

Charger

MBD

OUTPUT

CB

Battery

67