Clearing Alarm Logs; Alarm Adjustment; Mixed Air Alarm; Refrigerant Low Pressure - Bard MULTI-TEC W18AAPA Service Instructions Manual

Clearing Alarm Logs

To clear the alarm logs:
1. Press MENU key to go to the Main Menu screen.
2. Press UP or DOWN keys and ENTER key to enter
TECHNICIAN password 1313.
3. Press UP or DOWN keys to scroll to Settings; press
ENTER key.
4. Press UP or DOWN keys to scroll to Initialization;
press ENTER key.
5. Press UP or DOWN keys to scroll to Initialization
1/5; press ENTER key.
6. Press ENTER key to scroll to Delete alarm logs?
(see Figure 14).
7. Press UP or DOWN key to change from NO to YES.
8. Press ENTER key to clear all alarm logs.
FIGURE 14
Clearing Alarm Logs

Alarm Adjustment

Mixed Air Alarm

The mixed air alarm is used to indicate proper
operation of the economizer. An alarm will be generated
when the mixed air temperature is above or below two
independent setpoints.
This alarm can be adjusted by changing the alarm
setpoints and/or delay. The differential low references
the economizer control setpoint. For example, if the
economizer setpoint is 55°F (as shown in Figure 24
on page 17) and the differential is set to 10, the lower
limit for the mixed air alarm would be 45°F. The high
differential references the outdoor air temperature
setpoint that enables the economizer. For example, if
the outdoor air temperature setpoint for economizer
enable is set to 65°F and the high alarm is set to 5, the
alarm would actuate at 70°F. The alarm also has a delay
to help reduce nuisance alarms. With the delay set to
120 seconds, either the high mixed air or low mixed air
alarm will need to be active for 120 seconds before an
alarm will be generated.
Manual 2100-665G
Page 12 of 28
To adjust these values:
1. Press MENU key to go to the Main Menu screen.
2. Press UP or DOWN keys and ENTER key to enter
USER password 2000.
3. Press UP or DOWN keys to scroll to Sys Config;
press ENTER key.
4. Press UP or DOWN keys to scroll to Alarm Config
(A7); press ENTER key.
5. Press ENTER key to scroll to desired value Diff Lo,
Diff Hi or Del (see Figure 15).
6. Press UP or DOWN keys to adjust value.
7. Press ENTER key to save.
FIGURE 15
Adjusting Mixed Air Alarm Values

Refrigerant Low Pressure

When the low pressure switch indicates a low pressure
condition and there is an active call for cooling, the
controller will generate an alarm (after a delay). The
delay used by the low pressure alarm is determined
by the outdoor air temperature (OAT on display). If the
outdoor air temperature is below 55°F, the delay is 180
seconds (LDel on display). If the outdoor temperature
is above 55°F, the delay is 120 seconds (Del on
display). The unit will also have an address-based delay
that will affect start up time; the default is 5 seconds
multiplied by unit address. (The unit address-based
delay is only when the unit is in stand alone operation.)
Additionally, if the outdoor temperature sensor is not
used, the delay is set to 180 seconds. The controller
will try to run the refrigeration system two times before
the alarm will lock the compressor out.
If 15 minutes (Two Count Del value on display) passes
before the second attempt, the number of tries will be
reset.
To adjust these values:
1. Press MENU key to go to the Main Menu screen.
2. Press UP or DOWN keys and ENTER key to enter
USER password 2000.
3. Press UP or DOWN keys to scroll to Sys Config;
press ENTER key.