TOSHIBA
40
7.0 UPS Protection System
7.1
System Protection Features
The preceding one-line schematic illustrates the electrical locations of the protection devices
on the 75, and 100kVA UPS models.
7.2
System Protection Functions
The following charts shows the built-in UPS’s fault protection functions on the 75 and 100kVA
models.
Built-in UPS Fault Protection Functions
Protection Item
Inverter Overvoltage
(IVOV)
Inverter Undervoltage
(IVUV)
UPS Overload
LCD Message
INVERTER
OVERVOLTAGE
INVERTER
UNDERVOLTAGE
OUTPUT OVERLOAD
Cause
Control Malfunction; Feedback Error
Overload or short circuit at the load.
Operation Mode
after Fault
Bypass Operation; Chopper and Inverter Stopped
Inverter Overload: Transfer to bypass; Inverter stopped.
Bypass Overload: Inverter, Chopper, and Bypass stopped.
Audible Alarm
Yes: See Section 6.7 Audible Alarm Functions
Visible Alarm
Red Fault Lamp “on”
Inverter OL: No Fault Lamp
Bypass OL: Fault Lamp “on”
Relay Contact
Alarm
Fault Relay closed; Bypass Relay closed
Inverter OL: Bypass Relay closed
Bypass OL: Bypass Relay open and Fault relay closed
Auto-Retransfer
No
Inverter OL: Yes, if bypass ok
Bypass OL: No
Protection Item
Low Battery Voltage
(level-1)
Low Battery Voltage
(level-2)
Inverter Output Current Limit
LCD Message
Line-4 will read
“BATTERY LOW”
DC UNDERVOLTAGE
OUTPUT OVERLOAD
Cause
Battery Discharge
Battery Shutdown Level
reached
Load Inrush current
Operation Mode
after Fault
Battery Discharge
Shutdown: No Output
If Bypass ok, transfer to bypass; if not, current-limit mode
Audible Alarm
Yes: See Section 6.7 Audible Alarm Functions
Visible Alarm
Battery Lamp Flickers
NO
NO
Relay Contact
Alarm
Low Battery Relay closed
Bypass Relay closed
Auto-Retransfer
No
Yes, if bypass ok
Protection Item
Memory error (EERR)
Internal overheat
(OH)
DC circuit
overvoltage (DCOV)
DC circuit overcurrent
(DCOC)
LCD Message
MAIN EEPROM ERROR
OVERHEAT; INTERNAL
DC OVERVOLTAGE
DC OVERCURRENT
Cause
Control board chip error
Fan failure; high ambient
Chopper malfunction
Inverter / chopper fault
Operation Mode
after Fault
Start is inhibited
Bypass operation; chopper and inverter are stopped
Audible Alarm
Yes; continuous buzzer
Visible Alarm
RED fault lamp “ON”
Relay Contact
Alarm
Fault relay closed; bypass relay closed
Auto-Retransfer
NO