42 AGZ 010B through 034B IOMM AGZB1
Unit Test Mode
The unit test mode allows manual testing of controller outputs. Entering this mode requires
the following conditions.
• Unit Switch = OFF
• Manager password active.
• Available Unit Mode setpoint = TEST
A test menu can then be selected to allow activation of the outputs. It is possible to switch
each digital output ON or OFF and set the analog outputs to any value.
Power Up Start Delay
After powering up the unit, the motor protectors may seem to not work properly for up to
150 seconds. After the control is powered up, no compressor can start for 150 seconds. In
addition, the motor protect inputs are ignored during this time so as to avoid tripping a false
alarm.
Ice Mode Start Delay
An adjustable start to start ice delay timer will limit the frequency with which the chiller
may start in Ice mode. The timer starts when the first compressor starts while the unit is in
ice mode. While this timer is active, the chiller cannot restart in Ice mode. The time delay
is user adjustable.
The ice delay timer may be manually cleared to force a restart in ice mode. A setpoint
specifically for clearing the ice mode delay is available. In addition, cycling the power to
the controller will clear the ice delay timer.
Unit State
The Unit shall always be in one of three states. These states are Off, Auto, and Pumpdown.
Transitions between these states are shown in the following diagram (Figure 13, Unit State
Diagram).
T1: Off to Auto
All of the following must be true:
• Unit Enabled
• No Alarm
• IF Unit Mode = Ice THEN [Ice Timer Expired]
T2: Auto to Pumpdown
Any of the following must be true:
• Keypad Enable = Off
• BAS Enable = Off
• Remote Switch = Off
• Pumpdown Alarm Active
T3: Pumpdown to Off
Any of the following must be true:
• Unit Alarm
• Unit Switch Off
• No Compressors Running
T4: Auto to Off
Any of the following must be true:
• Unit Alarm
• Unit Switch Off
• No Compressors Running AND [Unit Mode = Ice AND Ice Delay Active]
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