TOSHIBA
7.0 UPS Protection System
7.1 System Protection Features
The following one-line schematic illustrates the electrical locations of the protection devices on
the 80 kVA UPS models.
7.2 System Protection Functions
The following tables show the built-in UPS fault-protection functions of the 80 kVA models.
Built-in UPS Fault Protection Functions
Protection Item
Converter Inverter
Static
Bypass
Charger/
Chopper
Isolating
XFMR
External
Batteries
Output
Power
Input
Power
MCCB
Power Flow
Overcurrent
Input Abnormal
Current-Limit
Overload
Over-Voltage /
Under-Voltage
Overheat
Low Battery
Overheat
Inverter Overvoltage
(IVOV)
Inverter Undervoltage
(IVUV)
UPS Overload
LCD Message
INVERTER
OVERVOLTAGE
INVERTER
UNDERVOLTAGE
OUTPUT OVERLOAD
Cause
Control Malfunction
Feedback Erro
Overload or short circuit at the load.
Operation Mode
Bypass Operation; Chopper and Inverter Stopped
after Fault
Inverter Overload: Transfer to bypass; Inverter stopped.
Bypass Overload: Inverter, Chopper, & 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
Battery Discharge Shutdown: No Output
after Fault
If Bypass OK, transfer to bypass
If not, current-limit mode
Audible Alarm
Yes: See Section 6.7 Audible Alarm Functions
isible Alarm
Batter
Lam
Flickers NO NO
Relay Contact
Al
rm
Low Battery Relay closed Bypass Relay closed
Auto-Retransfer
No Yes
if b
ass OK
DC circuit overvoltage
DCOV
Protection Item Memory error (EERR) Internal overheat (OH) DC circuit overcurrent (DCOC)
LCD Messa
e
MAIN EEPROM ERROR OVERHEAT
INTERNAL DC OVERVOLTAGE DC OVERCURRENT
Cause
Control board chi
erro
Fan failure
hi
h ambient Cho
er malfunction Inverter / cho
er fault
Operation Mode
after Fault
Start is inhibited Bypass operation; chopper and inverter are stopped
Audible Alarm
Yes
continuous buzze
Visible Alarm
RED fault lamp On
Relay Contact
Alarm
Fault relay closed; bypass relay closed
Auto-Retransfer
NO
52 4200FA User’s Manual
