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iWorx® MPU2
32
505-009, Effective: April 28, 2014
© 2014 Taco Electronic Solutions, Inc.
Filter Status
The filter status input is monitored to determine if the filter is operating properly. The input is used to indicate that main-
tenance is required on the filter. The controller application is not shutdown due to a filter alarm.
Real Time Clock (RTC)
The RTC will be set or synced by the LCI each day at midnight. The controller will utilize the RTC in conjunction with its
local backup schedule during periods when the LCI is not available.
Local Backup Schedule
The LCI normally determines the operating mode. You can define a local backup schedule for situations when the LCI
is not available. When the controller detects that the LCI is not available (after 10 minutes without communications), it
resorts to the local backup schedule that has been configured. If the local backup schedule is disabled, the controller
defaults to the occupied mode.
You configure the occupied and unoccupied times that are used in determining the current operating mode of the con-
troller when it is running the backup schedule. By default, both the unoccupied and occupied times are set to zero,
which disables the local backup schedule. This causes the controller to default to the occupied mode of operation when
communications are lost to the LCI for 10 minutes or longer.
Runtime Accumulations
The total runtime is accumulated for the heating, cooling, and fan outputs. The runtimes can be used to indicate that
maintenance is required on the equipment controlled by these outputs. An operator or maintenance personnel can
reset the runtime once servicing has been performed.
Alarms and Events
The MPU2 detects certain alarm conditions and sends them to the LCI. Before this can occur, the MPU2 must have
been configured by the LCI.
Digital Input Alarms
The MPU2 monitors the status of the digital inputs and generates alarms for the following events:
• Fan Failure
• Smoke Detect
• Mixed Air Low Limit
• Dirty Filter
• CO
2
Alarm
Supply Air Temperature Alarms
The following alarms can be generated based on supply air monitoring.
• Cooling Failed
• Heating Failed
• Heat Stuck On
Maintenance Alarm
A MPU2 provides programmable run limits for generating runtime maintenance alarms. When the cooling runtime,
heating runtime or fan runtime exceeds these limits, a maintenance alarm is sent to the LCI.