Table of Contents
8.0
A
LARMS
The microprocessor control system will audibly and visually signal all ENABLED Alarms (including
two (2) custom alarms). These special alarms can be chosen from the optional alarm list and/ or can
have their own fully custom text. The custom alarm inputs are contact closures wired from terminal
TB1-1 through a normally open contact to either TB1-2 (alarm 1) or TB1-3 (alarm 2). The alarms can
be enabled/disabled (refer to 6.0 - Microprocessor Control) and a time delay of 0-255 seconds can
be set. The alarms can also be programmed to either sound the alarm & activate the common alarm
relay OR to sound the alarm only
When a new alarm occurs, it is displayed on the screen and the audible alarm is activated. (If
communicating with a Liebert Site Monitoring Product, the alarm is also transmitted). The message
"PRESS ALARM SILENCE" will prompt the operator to silence the alarm. After the alarm is
silenced, the display will return to the Normal Status display. Alarms can be reviewed by selecting
the "ACTIVE ALARMS" feature. The alarms can also be silenced through communications with a
Liebert Site Monitoring Product unit.
Many alarms will reset automatically when the alarm condition is no longer represented and only
after it has been acknowledged by being silenced. The exceptions are:
• software alarms, i.e., Loss of Power and Short Cycle alarms will reset automatically 30 seconds
after being silenced or acknowledged; and
• specific alarms monitoring overload or high-pressure switches may require a manual reset
depending on the model.
8.1
Alarms: Definitions and Troubleshooting
The following list provides a definition and troubleshooting suggestions for each type of alarm. Refer
to 11.0 - Troubleshooting for additional details. If you need further assistance, contact your
Emerson supplier. THE CUSTOMER MUST SPECIFY ALARM(S) AT THE TIME OF ORDER.
OTHER DEVICES AND WIRING MAY BE REQUIRED AT THE FACTORY FOR SOME OF THE
ALARMS.
8.1.1
Custom Alarms
Custom alarm(s) messages are programmed at the LCD display. The message displayed may be
included in a list of provided alarms or it may be customized text (for up to two alarms). IF
CUSTOMIZED TEXT IS USED, MAINTENANCE PERSONNEL SHOULD BE INFORMED OF THE
ALARM FUNCTION AND THE REQUIRED ACTION.
8.1.2
High Head Pressure
Compressor head pressure is monitored with a pressure-sensor switch. (One SPDT pressure switch is
used). If head pressure exceeds 400 psig (2758kPag), the switch turns off the compressor contactor
and sends an input signal to the control. The condition is acknowledged by pressing the alarm silence
button on the wall box, which will clear if the head pressure is alleviated. If the head pressure alarm
has activated three times, the alarm will lock until the unit is serviced. After the head pressure
problem is fixed, reset the control by disconnecting power to the evaporator unit.
Air-Cooled Systems
Check for power shut off to the condenser, condenser fans not working, defective head pressure
control valves, dirty condenser coils or crimped lines.
Water/Glycol/ Systems
Check water regulating valves. Verify water/glycol flow (i.e., pumps operating and service valves
open). Is water tower or drycooler operating? Is the coolant temperature entering the condenser at or
below design conditions? Is AUX relay (terminals 70 & 71) operating during cooling to turn on the
drycooler?
53
Alarms
®
™
Liebert
Mini-Mate2
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