Liebert 3000 manual 5.1.16Short Cycle, 5.2.1Loss of Water Flow, 5.2.2Smoke Detected

Alarm Descriptions

5.1.16Short Cycle

On compressorized systems, if the compressor has exceeded 10 cooling starts in one hour or if the compressor has cycled five times in 10 minutes on the low pressure switch during non-cooling, the Short Cycle alarm will occur. This can be caused by low refrigerant level (but not low enough to acti- vate Low Suction Pressure alarm) or room cooling load is small compared to capacity of the unit.

Check for leaks, crimped lines, and defective components. If room load is low, increase sensitivity to reduce cycling (proportional control). On GLYCOOL units, dirty filters can cause the coil freeze stats to cycle the compressor.

5.2Optional/Custom Alarms

5.2.1Loss of Water Flow

Available only with 3-way valves and occurs when no water flow is detected in the chilled water or condenser water supply line. An optional flow switch is required for this alarm. Check for service valves closed, pumps not working, etc.

5.2.2Smoke Detected

Smoke is detected in the return air by an optional Liebert Smoke Detector. Check for source of smoke or fire, and follow appropriate emergency procedures.

5.2.3Standby GC Pump On

The primary pump has failed, and the standby pump is activated (glycol cooled and GLYCOOL units only).

Check for problems with the primary pump (fuses blown, motor burnout, service valve shut, stuck check valve, impeller damage, etc.).

5.2.4Standby Unit On

The primary environmental control system has had an alarm condition, and the standby system is activated.

5.2.5Water Under Floor

Water is detected by an optional Liebert Water Detection System. Check under the raised floor for water or other leaks.

NOTE

The alarms are specified by the customer at the time of order. All alarms will report to a Liebert remote monitoring unit. Additional devices and wiring may be required at the factory for some of the alarms.

41