Limit Events - Daikin WGZ030DW Operating And Maintenance Manual

Alarm Log
An alarm log stores the last 25 alarms and/or events to occur. When an alarm or event occurs, it is put
into the first slot in the alarm log and all others are moved down one, dropping the last entry. In the alarm
log, the date and time the alarm occurred are stored, as well as a list of other parameters. These
parameters include compressor states, evaporator pressure, condenser pressure, number of fans on, OAT,
and evaporator LWT.
Active Alarms
When an alarm occurs, it appears in the active alarm list. The active alarm list holds a record of all active
alarms, which includes the date and time each occurred.
Clearing Alarms
A password is NOT required to clear an active alarm. Active alarms must be cleared at the unit controller.
To clear active alarms scroll down to the end of the Active Alarm list press Enter to clear all active
alarms. If the user attempts to clear an alarm while the alarm condition still exists, a new alarm will be
generated immediately.

Limit Events

The following events do not cause a rapid stop but limit operation of the chiller in some way as described
in the Action Taken. All limit events do NOT appear in the Active Alarm window and are NOT logged in
the Alarm Log
Low Evaporator Pressure - Hold
Event description (as shown on screen): Evap Press Low HoldN
Trigger:
This event is triggered if all of the following are true:
•
circuit state = Run
•
circuit is not currently in a low OAT start
•
has been at least 30 seconds since a compressor has started on the circuit.
•
evaporator pressure <= Low Evaporator Pressure - Hold set point
Action Taken: Inhibit staging on of additional compressors on the circuit.
Reset: While still running, the event will be reset if evaporator pressure > (Low Evaporator Pressure -
Hold set point + 8psi for R134a/R22/R407C or 13 psi for R410A). The event is also reset if the circuit
state is no longer run.
Low Evaporator Pressure - Unload
Event description (as shown on screen): EvapPressLow Unload N
Trigger:
This event is triggered if all of the following are true:
•
circuit state = Run
•
more than one compressor is running on the circuit
•
circuit is not currently in a low OAT start
•
has been at least 30 seconds since a compressor has started on the circuit.
•
evaporator pressure <= Low Evaporator Pressure - Unload set point for a time greater than half
of the current freezestat time
Action Taken: Stage off one compressor on the circuit every 10 seconds, except the last one.
Reset: While still running, the event will be reset if evaporator pressure > (Low Evaporator Pressure -
Hold set point + 8psi for R134a/R22/R407C or 13 psi for R410A). The event is also reset if the circuit
state is no longer run.
28 WGZ030D through WGZ200D OMM 1130-2