APC SY160K160H User Manual

Maintenance Bypass Alarm The system is in maintenance 

bypass: the Q2 switch is open 
and the Q3 switch is closed.

No corrective action necessary.

Output V <Ln-N>

Voltage Under Limit

Phase-to-neutral output voltage 
for phase <L-N> has dropped 
below the configured limit.

Evaluate the threshold setting. If necessary, 
adjust it for your situation.

Output V <Ln-N>
Voltage Over Limit

Phase-to-neutral output voltage 
for phase <L-N> exceeded the 
configured limit.

Evaluate the threshold setting. If necessary, 
adjust it for your situation.

Output I L<n>
Current Over Limit

Current of output phase <n> 
exceeded the configured limit.

Evaluate the threshold setting. If necessary, 
adjust it for your situation.

Output I L<n>
Current Under Limit

Current of output phase<n> 
dropped below the configured 
limit.

Evaluate the threshold setting. If necessary, 
adjust it for your situation.

Output FDev
Freq Out of Range

Frequency of the output current 
is above or below the range that 
is configured as acceptable.

Evaluate the threshold setting. If necessary, 
adjust it for your situation.

<User Contact Name>
Alarm Active

A user-configured contact 
connected to the system is 
reporting an alarm condition.

Determined why the alarm has occurred. This 
is a user-specific alarm setting.

No UPS Input
Breaker Q1 Open

The Q1 circuit breaker is open, 
and the UPS is disconnected 
from the input voltage.

Close the Q1 switch to re-connect the UPS to 
utility/mains power.

No Panel Feed
Breakers Q2 & Q3 Open

The Q2 & Q3 circuit breakers 
are open, and the system is not 
supporting connected 
equipment.

For safety reasons, ensure the switches were 
not closed for maintenance purposes. If not, 
close Q2 for UPS operation, and Q3 for 
maintenance bypass.

Atypical Bypass Mode
Alarm 

The system state as set by the 
Q1, Q2, & Q3 breakers is in a 
non-typical bypass mode.

Option 1: Resume normal UPS operation.
Option 2: Go to maintenance bypass.