Alpha Technologies AMPS HP2 Power System Installation & Operation Manual page 75

8.2.3 Taking Power from DC Source
The inverter system can take power from the DC source (usually batteries) under three conditions:
1. AC mains is lost;
2. Manual DC Priority is enabled;
3. AC Input power limit is enabled.
When AC mains is lost, the inverters will always take power from the DC source if available.
Using Manual DC Priority
It is possible to manually instruct the inverters to take some amount power from DC. This can be useful for testing
or to manually reduce the AC input power during peak periods. Manual DC Priority takes precedence over AC
Input Power Limit when both are enabled.
To use Manual DC Priority:
1. Go to Power System > Inverter System > System Functions > Manual DC Priority.
2. From the Manual DC Priority table, click edit icon.
3. Select Enable in Manual DC Mode drop-down menu and click Save.
4. Click the edit icon to set the Desired DC Input Power to the desired value. This value is a percentage of
output power that will be taken from DC (with the rest coming from AC input).
5. Disable Manual DC Mode when complete.
8.2.4 Using AC Input Power Limit
The AC Input power limit is a feature that allows the controller to dynamically adjust the amount of power taken
by the AC input, by taking some power from the DC input. The controller will continue to take power from the DC
input until a user configured threshold is reached or the feature is disabled.
1. Go to Power System > Inverter System > System Functions > AC Input Power Limit.
2. Enable the AC Input Power Limit.
3. Set the Desired AC Input Power to the required value. The controller will attempt to limit the AC input power
to this value by taking some power from the DC input.
4. Disable AC Input Power Limit when complete or when the battery needs to be charged.
AFTER COMPLETING THIS TASK: The battery may be depleted and require charging.
8.2.5 Replace Fan
The fan inside each inverter has a limited lifetime. When this lifetime has expired the inverter will have an active
alert called Fan Life Elapsed. To prevent an unexpected fan failure that could compromise system redundancy,
it is recommended that the fan be replaced when this alert occurs.
To clear the alert, go to Power System > Inverter System > Inventory > Inverters > Status, and click the
details icon of the inverter with the alert, then press the Clear Fan Life Elapsed Alert button.
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