Alpha Technologies CXPS 48-1.2-225 48 Vdc - Manual (Page 36)

053-691-B1 Rev E Page 28 of 33
7 Operation
7.1 Main rectifier states
Rectifier operation can be broken up into five main states:
1. Off
2. Start Delay
3. Soft Start
4. Normal Operation
5. Turning Off
Each state is distinct and necessary for the operation of the rectifier. These states are briefly described below.
7.1.1 Off state
The rectifier is in the Off state immediately after power is applied to the rectifier or after a rectifier shutdown. The
shutdown source may be a remote or local shutdown, an AC shutdown, an over voltage shutdown, or a thermal
shutdown.
When the rectifier is in the Off state, the DC-DC converter is turned off. The controller monitors its inputs for the
proper conditions that allow the start-up sequence.
When the rectifier start-up conditions have been met, the rectifier will transition to the Start Delay state.
7.1.2 Start Delay state
When the rectifier is in the Start Delay state, the DC-DC converter is held off and not sourcing power, and waits
for a predetermined time before transitioning to the next state.
The controller continues to monitor its inputs during the Start Delay state.
After the Start Delay state, the rectifier will transition to the Soft Start state.
7.1.3 Soft Start state
When the rectifier is in the Soft Start state, the voltage and current output of the rectifier are gradually increased.
This is done to reduce the instantaneous load on the AC source. If a load is present, the rectifier begins to source
power.
When the voltage and current limits are reached, the rectifier will transition to the Normal Operation state.
7.1.4 Normal Operation state
During the Normal Operation state, the rectifier will be performing all of its specified rectifier functions.
From this state, the only valid transition is to the Turning Off state, which happens if the rectifier is required to shut
down.
7.1.5 Turning Off state
The Turning Off state consists of a short delay required to initialize some parameters before the rectifier actually
shuts off.
After the short delay, the rectifier transitions to the Off state.