User Manual

Table Of Contents

1.6 UPS States and Operating Modes

NOTE: See

LED Indicators on page31, for description of the run-indicator and alarm-indicator LEDs

mentioned in this section.

1.6.1 Normal Mode

When utility power is normal, Normal mode employs the rectifier and inverter to provide voltage- and

frequency-stabilized power to the load. The charger charges the battery in normal mode. On the front-

panel display, the run-indicator (green)is On, the alarm indicator is OFF, and the buzzer is silent.

1.6.2 Bypass Mode

Bypass mode supplies power to the load from the bypass source (utility power) if an overload or fault

occurs during normal operation. On the front-panel display, the run indicator (green) is On, the alarm

indicator (yellow)is On, and the buzzer beeps once each seconds. The LCD "Current" screen displays "On

Bypass."

NOTE: If utility power fails or if the utility voltage goes outside of the permissible range during bypass-

mode operation, the UPS shuts down and no output is supplied to the load.

1.6.3 Battery Mode

Battery mode supplies battery power to the load if utility power fails or if the utility voltage goes outside of

the permissible range. On the front-panel display, the run indicator (green) is On, the alarm indicator

(yellow)is On, and the buzzer beeps once each second. The LCD "Current" screen displays "On Battery."

NOTE: The batteries are fully-charged before shipment. However, transportation and storage

inevitably cause some loss of capacity. To ensure adequate back-up time, charge the batteries for at-

least 8 hours before first start-up.

NOTE: If utility power fails and the batteries are charged, you may cold-start the UPS in battery mode

and use battery power to extend system availability for a time.

NOTE: Powering-off the UPS when it is in battery mode results in loss of output power to the

connected load.

1.6.4 Frequency Converter Mode

All models of the GXT5 are capable of frequency conversion. Frequency Conversion Mode can be selected

using the configuration program. Allowable frequency operating modes include:

• Auto Sensing - 50 Hz or 60Hz – Bypass Enabled

• Auto Sensing - 50 Hz or 60Hz – Bypass Disabled

• Frequency Converter - 50 Hz – Bypass Disabled

• Frequency Converter - 60Hz – Bypass Disabled

NOTE: The default for all models of the Liebert® GXT5 is “Auto Sensing - 50 Hz or 60Hz – Bypass

Enabled.”

1 GXT5 Description