Liebert 3000 manual 5.1Standard Alarms, 5.0ALARM DESCRIPTIONS, 5.1.1Change Filter

Alarm Descriptions

5.0ALARM DESCRIPTIONS

The Advanced Microprocessor (A) and the Advanced Microprocessor with Graphics (G) Control sys- tems will audibly and visually annunciate all ENABLED alarms, including the four custom alarms. With the Advanced & Advanced with Graphics Controls, the customer alarms can be from the optional alarm list and/or can have their own fully custom text. Two alarms may be selected as cus- tom for the Advanced Microprocessor and four can be custom for Advanced Microprocessor with Graphics. The custom alarm inputs are 24 VAC, which is available from the Liebert unit. Alarms are wired from terminal 24 through a normally open contact to locations 50, 51, 55, and 56, respectively, for alarms 1 through 4.

The Advanced and Advanced with Graphics alarms can be delayed from 0 to 255 seconds (for Advanced see Setup Alarms on page 9; for Advanced with Graphics, see 3.4.3 - Setup Alarms). The Advanced alarms can be ENABLED or DISABLED and can also be programmed to energize the Common Alarm Relay or to “alarm only” and not energize the Common Alarm Relay.

The Advanced Microprocessor with Graphics alarms can be selected as WARNING, URGENT, or DIS- ABLED. If selected to be a WARNING, they are annunciated after the Time Delay, but do not ener- gize the Common Alarm Relay. If selected as URGENT, they are annunciated after the Time Delay as a WARNING alarm and then re-annunciated after a user programmable period from 0 minutes to 999 hours as an URGENT alarm. When annunciated as an URGENT alarm, the Common Alarm Relay is activated. The custom alarm inputs of the Advanced Microprocessor with Graphics can be designated to be “Status Only.” As Status Only the custom alarm input is referenced as a digital input and is no longer treated as an alarm. It is for monitoring only and can be reviewed by selecting “ANALOG/DIG-

ITAL INPUTS.”

When a new alarm occurs, it is displayed on the screen and the audible alarm is activated. If commu- nicating with a Liebert Site Product, the alarm is also transmitted. The display will also show a mes- sage to “PRESS ENTER KEY TO SILENCE” the alarm. After the alarm is silenced, the display will return to the Normal Status Display. For the Advanced Microprocessor with Graphics, the bell and hammer are shown at the top of the Normal Status Display. For the Advanced Microprocessor, the bottom line will display the number of Active Alarms. The active alarms can be reviewed on the Advanced Microprocessor Controls by selecting “ACTIVE ALARMS.”

The alarms can also be silenced through communications with a Liebert Site Products unit. Most alarms will reset automatically when the alarm condition is no longer present and only after it has been acknowledged by being “Silenced.” The exceptions are:

1.The three software alarms: Loss of Power, Low Suction Pressure, and Short Cycle, which reset automatically 90 minutes after being “Silenced” or acknowledged.

2.Some alarms such as overloads and high pressure switches may require a manual reset depending on your model.

A history of 10 alarms for Advanced (see 2.4.3 - Alarm History Log) and 60 alarms for Advanced with Graphics (see 3.4.2 - Alarm History Log) is retained in nonvolatile memory.

This section provides a definition of each available alarm. Troubleshooting suggestions are included. Refer to 7.0 - Troubleshooting for more details. If you need assistance with your environmental con- trol system, contact your Liebert supplier.

5.1Standard Alarms

5.1.1Change Filter

Periodically, the return air filters in the environmental units must be changed. The Change Filter alarm notifies the user that filter replacement is necessary. A differential air pressure switch closes when the pressure drop across the filters becomes excessive. The switch is adjustable using the proce- dure on the switch label.

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