Operation
Smart Distribution Panel with ATS 21
Problem—loss of automatic operation
Typically, the Not In Automatic Operation LED tracks the state of the Automatic Operation
switch (i.e., 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 Enable
position, check messages on the display interface to determine the cause—one of the following
conditions exist:
1. The ATS attempted to actuate either the Source 1 or Source 2 switch, and could not.
When a switch cannot actuate, one of the four following actions cannot take place:
– The Source 1 switch cannot turn ON (Close)
– The Source 1 switch cannot turn OFF (Open)
– The Source 2 switch cannot turn ON (Close)
– The Source 2 switch cannot turn OFF (Open)
When the ATS cannot actuate a switch, it will attempt several more times before stopping.
There are two cases of this condition:
–The load is receiving supply from mains, and the Source 1 switch trips.
When the Source 1 switch trips, the ATS will try to re-close 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 be in Not in Automatic Operation mode until it
is reset (see page 20).
–The load is receiving supply from the generator, and the Source 2 switch trips.
When the Source 2 switch trips, the ATS will try to re-close the switch, and after several
attempts one of two things will happen, depending upon whether mains is available.
• If mains is not available, the generator will continue to run until mains is available. Once
mains is available, the ATS will switch to mains and then turn off the generator. Mains will
supply power to the ATS, and the ATS will be in Not in Automatic Operation mode until
automatic operation is reset (see page 20).
• If mains is available, the ATS will switch to mains and then turn off the generator. Mains
will supply power to the ATS, and the ATS will be 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 EPO switch is engaged, the ATS Source 1 and Source 2 switches are tripped open,
and the generator’s emergency stop signal is engaged—the ATS is no longer supplying output
power. The ATS immediately goes into Not in Automatic Operation mode. The ATS stays in
Not in Automatic Operation 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).