Nordic ATWC Series, Installation And Service Manual, Page: 39 / 106

PRELIMINARY: 24-Sep-2021 Page 39 002536MAN-00
View-->Alarms, Limits and Faults
The alarms page has four tabs:
1. ALARMS - Current alarm status, alarm count, high and low refrigeration alarm cutout values, and short cycle timer.
2. ALARMS LIST - List of alarms that have occurred since the PC APP has been operating (this will be lost when the PC is discon-
nected from the control board.)
3. LIMITS - Limits in effect which prevent compressor operation but that do not cause an alarm.
4. FAULTS - List of board hardware faults.
View-->Alarms, Limits and Faults (ALARMS Tab):
NOTE: Greyed out Alarms in the PC APP are not applicable to the system setup and are not monitored by the control board.
NOTE: Refer to Alarms and Faults screenshot below to see which alarms have a count.
Alarms without a count:
These alarms only occur one time at which point they immediately create a Permanent Alarm .
Alarms with a count:
When an alarm occurs the compressor will stop, the alarm count will increase and the
Short Cycle Timer
will start. When the
SC Timer
expires the compressor will re-start. If no further alarms occur within
Count
Reduce Time
, the alarm count will be reduced by 1. If another alarm occurs within
Count Reduce
Time
(see Configuration Page ) the count will increase by 1. If alarms continue to occur, when the
alarm count reaches the
Maximum Count
value a
Permanent Alarm
will occur.
Master Alarm:
This alarm occurs when any permanent alarm occurs. It is used to simply indicate that there is an alarm.
Permanent Alarm:
The compressor will be locked out until the
Permanent Alarm
is manually reset either by cycling the
power or clicking on the
RESET
button
Low Pressure:
A low pressure alarm occurs when the suction pressure drops to or below the
Low Pressure Cutout
value. The low pressure is checked just before a compressor start; if it is OK the compressor will start,
otherwise an alarm will occur. When the compressor starts, low pressure alarm will be ignored for the
number of seconds that
Low Pressure Ignore
is set to, after which the low pressure alarm will be
re-enabled. This allows a dip in suction pressure below the cutout point during startup without causing a
nuisance alarm.
High Pressure:
A high pressure alarm occurs when the discharge pressure rises to or above the
High Pressure Cutout
Value.
Compressor Status:
This alarm occurs when there is current draw on the compressor but no call for the compressor to be on
(i.e. welded contactor) or when there is call for the compressor to be on but there is no compressor current
draw (i.e. manual high pressure control is open or contactor failure). Requires current sensor accessory.
Phase Monitor:
This alarm occurs when the Phase Monitor detects a fault condition and sends a fault signal to the control
board. For three phase units only and requires Phase Monitor accessory.
Low Charge:
This alarm occurs if the EEV has been at >99% for 20 minutes within first hour of a cycle.
LOC (Loss of Charge):
This alarm occurs if both the low pressure and high pressure sensors are below 30 psig (207kPa).
Multiple Defrosts:
This alarm occurs if a second defrost occurs immediately after the defrost disabled timer expires from a
previous defrost cycle. It indicates abnormally low suction pressure.
Go the Alarms Troubleshooting section of the Troubleshooting section of the manual to address alarm issues.
This button will erase all
alarms and alarm counters,
including a permanent alarm.
Low Pressure cut out.
High Pressure cut out.
This button will reduce the
short cycle timer value to 10
seconds.
Greyed out alarms are not
applicable to the system.
Master Alarm
occurs
when any alarm occurs.
Short Cycle Timer counts
down time until the next
compressor start is allowed.
WARNING: Repeated
resets can freeze and
rupture heat exchang-
ers, ruining the heat
pump and voiding the
warranty. The source
of the alarm should be
determined before re-
setting the unit if pos-
sible or during opera-
tion after a reset.
NEEDS
UPDATE