Unit installation

57
ALARMS
Alarms are handled only if the controller is in ‘on’ status. In case of system failure, the controller displays on the
U.I. LCD the relevant error messages complete with the faulty circuit number. Once the alarm condition has been
reset, the error messages disappear automatically or, in some particular cases remain until the ESC key is
pressed (as shown in the display). When an alarm is present the General Alarm Indication relay is activated.
If manufacturer setup M76=7 and fans number M33≤2 then, when a single circuit alarm is present, the fan#3
digital output is activated (relay 11 for first circuit and relay 15 for second circuit).
Following a list of the possible error conditions:
Anti-Freeze Alarm
For single barrel systems (M16=0) if the lowest temperature between LWT and RWT is below (<) M27 for more
than 1 second (selectable because it may vary with percentage of additives added) or for multi barrels systems
(M16=1) if the lowest temperature between LWT, RWT, EV12T, EV34T is below (<) M27 for more than 1 second
(selectable because it may vary with percentage of additives added):
• Switch on the general alarm indication relay
• Switch off all compressors
• Message: "ALARM ICE HAZARD "
• Manual reset through the ESC key
Oil Pressure alarm
For reciprocating compressors (M14 = 1) the OP Oil Pressure alarm is as follows:
If the compressor is running and oil pressure – suction pressure (PO-PS) < PO_Diff_oil (M65) for more than
Time_oil_alarm (M66):
• Compressor is halted without pump down procedure;
• Message: "ALARM COMPRESSOR # OIL PRESSURE LOW";
• Manual reset through the ESC key .
Compressor Magnetic Circuit Breaker
If the Circuit breaker input is high for more than 1 second:
• Compressor is halted without pump down procedure
• Message: "ALARM COMPRESSOR # BREAKER FAULT"
• Manual reset through the ESC key
Compressor Solid State Protection System SSPS (winding thermistors)
If the Thermistor input is high for more than one second:
• Compressor is halted without pump down procedure
• Message: "ALARM COMPRESSOR # SSPS FAULT"
• Manual Reset through the ESC key.
Probes Warning
If one or more probes go in underflow (short circuit) or overflow condition (open circuit):
• Compressor is halted without pump down procedure
• Message: "WARNING COMPRESSOR # PROBE X OUT OF RANGE"
• Automatic reset after the end of the alarm condition
• If it is broken the probe where the control is made (check) then
if TC = LWT then control on RWT and new set = old set + 5°
if TC = RWT then control on LWT and new set = old set - 5°
automatic reset at the end of alarm condition.
Temperature Warning
If Tc > (Set_T + Delta_T_Alarm M25) for a period longer than t_temp_alarm (M26):
• Message: "ALARM WATER OVERTEMP."
Automatic reset when Tc < Set_T or manual pressing <ESC>
This alarm is disabled for the first 6 hours after the machine start.
Suction Pressure Alarm
If the suction pressure (PS < Set Alarm_PS M63) for more than M64 seconds (this check is bypassed until the
end of compressor minimum on time and during pump-down):