American Power Conversion 250 A - Manual (Page 31)

Automatic Operation
InfraStruXure Power Generation System 21
Problem—loss of automatic operation
Typically, the Not In Automatic Operation LED tracks the state of the Automatic Operation
switch (e.g., the LED is lit when the Automatic Operation switch is in the Disable position). If the
Not In Automatic Operation LED is lit while the Automatic Operation switch is in the E nable
position, check messages on the display interface to determine which of these conditions exist:
1. The ATS unsuccessfully attempted to actuate either the Source 1 or Source 2 switch. This
identifies the existence of one of the following situations:
– The Source 1 switch cannot turn ON (closed)
– The Source 1 switch cannot turn OFF (open)
– The Source 2 switch cannot turn ON (closed)
– The Source 2 switch cannot turn OFF (open)
When the ATS cannot actuate a switch, it will attempt to actuate the switch several more times
before discontinuing further attempts. There are two causes of this condition:
– The load is receiving power from the utility, and the Source 1 switch trips.
When the Source 1 switch trips, the ATS will try to reclose the switch. If the switch cannot be
closed, the ATS will start the generator and then close the Source 2 switch. The load will be
powered by the generator and the ATS will revert to Not in Automatic Operation mode until
it is reset (see page 20).
– The load is receiving power from the generator, and the Source 2 switch trips.
When the Source 2 switch trips, the ATS will try to reclose the switch. After several attempts,
one of two things will happen depending on whether utility power is available:
• If utility power is not available, the generator will continue to run until utility power
becomes available. Once utility power is available, the ATS will switch to the utility and
turn off the generator. The utility will supply power to the ATS, and the ATS will remain in
Not in Automatic Operation mode until automatic operation is reset (see page 20).
• If utility power is available, the ATS will switch to the utility and turn off the generator.
The utility will supply power to the ATS, and the ATS will remain in Not in Automatic
Operation mode until automatic operation is reset (see page 20).
2. The data center EPO switch that is connected to the ATS EPO interface was engaged.
When the data center EPO is engaged, the Source 1 and Source 2 switches are tripped open. The
generator’s emergency stop signal becomes engaged and the ATS is no longer supplying output
power. The ATS immediately goes into Not in Automatic Operation mode and stays in this
mode until the system is reset. To reset the system, disengage the data center EPO switch and
reset automatic operation on the generator and on the ATS (see page 20).