Delta DPS-500K, User Manual, Page: 140 / 152

11 - 4
Ultron DPS Series
No. Alarm Message Possible Cause Solution
18 PWR UNIT #n
INV OVER HEAT
SHUTDOWN 1. Fans have abnormalities.
2. Foreign matter is stuck in
the fans.
Check if fans work abnormally or
foreign matter is blocking a fan. If
yes, contact service personnel. If not,
please decrease some critical loads.
19 PFC SCR FAULT 1. PFC SCR is damaged.
2. Driving circuit is damaged.
Contact service personnel.
20 PWR UNIT #n DC
BUS NOK DC BUS voltage is too high or
too low. Contact service personnel.
21 PWR UNIT #n INV
OUTPUT NOK
SHUTDOWN Inverter’s output voltage is too
high or too low. Contact service personnel.
22 UPS OUTPUT
FAULT
SHUTDOWN Inverter’s output voltage is too
high or too low. Contact service personnel.
23 INV OVER
CURRENT Output might have shorting
issues. Contact service personnel.
24 PWR UNIT #n INV
SHORT CIRCUIT
SHUTDOWN Output might have shorting
issues. Contact service personnel.
25 PWR UNIT #n
INV STS FAIL
SHUTDOWN 1. Inverter’s static switch is
damaged.
2. Inverter’s driving circuit is
damaged.
Contact service personnel.
26 BYPASS STS
OVER HEAT 1. Fans have abnormalities.
2. Foreign matter is stuck in
the fans.
3. The UPS is overloaded.
Check if fans work abnormally or
foreign matter is blocking a fan. If
yes, contact service personnel. If not,
please decrease critical loads.
27 BYPASS INPUT
VOLT OR FREQ
NOK 1. The Bypass Switch (Q2) is
turned off.
2. Bypass voltage or
frequency is abnormal.
1. Check if the Bypass Switch (Q2) is
turned off. If yes, turn it on.
2. If the Bypass Switch (Q2) is turned
on but the alarm still exists, contact
service personnel.
3. Check if bypass voltage or
frequency is abnormal. If yes,
please wait until bypass AC source
becomes normal.