Operation
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Operating States
A state machine implemented within the CCU2 control software governs the
operation of the PV225S with clearly defined transit ions between its operating
states. There are five steady-stat e operating states and numerous intermediate
transition states.
• Power Tracking
• Transition
•Shutdown
• Fault
• Manual Current
• Matrix Test
• Automatic Sleep Test

Power Tra cking

This is the standard operating state of the PV225S. The PV225S ma ximum power
tracker will demand maximum power fro m the PV array, given sufficient PV
irradiance.
The user should be aware of the following conditions governing PV225S state
transitions:
• Qualified utility voltage must be prese nt for all states of operation.
• Fault states are automatic from any state of operation. A fault will cause the
PV225S to immediately stop processing all pow er. The fault condition will be
reported to the operator interface LCD.
• Most PV225S faults are latching and must be cleared at the opera tor interface
keypad before transitioning to another oper ating state.
• The ON/OFF switch, located on the front door of the PV225S, must be in t he
ON position for all operating states except Matrix Test, in which case it must
be in the OFF position.

Tra ns it io n

The intermediate transition states provide an or derly progression from one
operating state to the next. The user has the ability to manually transition the
PV225S between operating states via the operator inte rface keypad or remotely
using the GUI software. Manual transitions are initiated by entering a “Goal
State”, where the goal state is the desired operati ng state. Given all applicable
system parameters are within acce ptable limits, and the request is valid within the
state machine, the PV225S will initiate the proper sequence o f operations
necessary to progress to the requested goal state. Refer to Figure 2-1 on page 2–3
for an illustration of valid state transitions .