Off-line (Standby) Single Phase Uninterruptible Power Supplies (UPS)
Last Updated: April 1, 2025
Description
Off-line (Standby) Single Phase Uninterruptible Power Supplies (UPS) are devices designed to provide backup power to electrical loads during power outages. They typically remain inactive during normal power conditions, allowing the connected equipment to receive power directly from the main supply. When a power failure occurs, the UPS switches to battery power to maintain the supply to the connected devices.
Working Principle
The working principle of an off-line UPS involves monitoring the incoming power supply and switching to battery power when a power drop or outage is detected. During normal operation, the power is derived directly from the power line. In the event of a power failure, a battery-powered inverter is activated to continue supplying power to the load. This transition is typically seamless, ensuring that the connected equipment remains operational without interruption. Off-line UPS systems are useful because they provide essential power backup and surge protection, ensuring the safety and reliability of sensitive electronic equipment.
Applications
Off-line UPS systems are commonly used in environments where power outages are infrequent but can cause significant disruption. Specific examples include personal computers, small office equipment, and home entertainment systems. These systems are ideal for protecting devices that require a basic level of power protection without the need for continuous power conditioning.
Advantages over other Single Phase Uninterruptible Power Supplies (UPS)
Off-line UPS systems offer several advantages over other types of single-phase UPS systems. They are generally more cost-effective due to their simpler design and lower component count. Additionally, they consume less power during normal operation since they do not continuously condition the power supply. This makes them an attractive option for users who need basic power protection without the higher costs associated with more complex UPS systems.
Limitations
One of the primary limitations of off-line UPS systems is their lack of power conditioning during normal operation. They do not regulate voltage fluctuations or filter out electrical noise, which can be a disadvantage in environments with unstable power supplies. Additionally, the transition time from mains power to battery power, although brief, may not be suitable for highly sensitive equipment that requires zero transfer time.
Considerations
When considering an off-line UPS, it is important to evaluate factors such as initial costs, operating expenses, and maintenance requirements. Off-line UPS systems typically have lower initial costs compared to other UPS types, making them an economical choice for basic applications. However, their lack of power conditioning may lead to higher operating expenses if additional equipment is needed to manage power quality. Durability and reliability are generally good, but regular maintenance of the battery is necessary to ensure optimal performance. Replacement and maintenance costs should also be factored into the overall cost of ownership.
from DigiKey
DC-UPS MODULE 24V 10A [See More]
- Technology: Off-line (Standby)
- Mounting Options: Din Rail
- Watt Rating: 0.2400
from DigiKey
CLIQ M DC-UPS MODULE 24V/10A [See More]
- Technology: Off-line (Standby)
- Input Voltage Range: 24
- Watt Rating: 0.2400
- Mounting Options: Din Rail
from DigiKey
CLIQ M DC-UPS MODULE 24V/20A [See More]
- Technology: Off-line (Standby)
- Input Voltage Range: 24
- Watt Rating: 0.4800
- Mounting Options: Din Rail
from DigiKey
CLIQ M DC-UPS MODULE 24V/40A [See More]
- Technology: Off-line (Standby)
- Input Voltage Range: 24
- Watt Rating: 0.9600
- Mounting Options: Din Rail
from DigiKey
DIN RAIL BUFFERMOD 6KWS 24V 15A [See More]
- Technology: Off-line (Standby)
- Full Load Runtime: 0.1500
- Watt Rating: 0.3600
- Mounting Options: Din Rail
from DigiKey
DIN RAIL UPS 24V 10A W/ 5AH BAT [See More]
- Technology: Off-line (Standby)
- Mounting Options: Din Rail
- Watt Rating: 0.3600
from DigiKey
DIN RAIL UPS CONTR 24V 3.9-40AH [See More]
- Technology: Off-line (Standby)
- Mounting Options: Din Rail
- Watt Rating: 0.3600
from DigiKey
DIN RAIL UPS CONT 24V 3.9-150AH [See More]
- Technology: Off-line (Standby)
- Mounting Options: Din Rail
- Watt Rating: 0.6000
from DigiKey
DIN RAIL UPS CONTR 24/12V 240W [See More]
- Technology: Off-line (Standby)
- Mounting Options: Din Rail
- Watt Rating: 0.3600
from DigiKey
DIN RAIL UPS CONTR 24V 17-130AH [See More]
- Technology: Off-line (Standby)
- Mounting Options: Din Rail
- Watt Rating: 0.3600
from DigiKey
DIN RAIL BUFFERMOD 12KWS 24V 15A [See More]
- Technology: Off-line (Standby)
- Full Load Runtime: 0.3000
- Watt Rating: 0.3600
- Mounting Options: Din Rail
from DigiKey
UPS POWER SUPPLY 24VDC 120W [See More]
- Technology: Off-line (Standby)
- Mounting Options: Din Rail
- Watt Rating: 0.1200
from DigiKey
UPS CONTROLLER 12VDC 360W [See More]
- Technology: Off-line (Standby)
- Mounting Options: Din Rail
- Watt Rating: 0.3600
from DigiKey
UPS CONTROLLER 24VDC 720W [See More]
- Technology: Off-line (Standby)
- Mounting Options: Din Rail
- Watt Rating: 0.7200
from DigiKey
UPS 24V 40A DIN RAIL [See More]
- Technology: Off-line (Standby)
- Input Voltage Range: 24
- Watt Rating: 0.9600
- Mounting Options: Din Rail
from DigiKey
PWR SUPP, BATT & COND [See More]
- Technology: Off-line (Standby)
- Mounting Options: Din Rail
- Input Voltage Range: 24
- Standards / Compliance: CE, cURus, EAC, UKCA
from DigiKey
PWR SUPP, BATT & COND [See More]
- Technology: Off-line (Standby)
- Mounting Options: Din Rail
- Input Voltage Range: 24
- Standards / Compliance: CE, EAC, UKCA
from DigiKey
UPS 24VDC 44A 3 PHASE INPUT [See More]
- Technology: Off-line (Standby)
- Mounting Options: Din Rail
from DigiKey
ULTRA CAPACITOR MODULE, 12/24VDC [See More]
- Technology: Off-line (Standby)
- "Backed Up" Electrical Outlets: 1
- Input Voltage Range: 24
- Mounting Options: Tower Type
from DigiKey
OFFLINE UPS 500VA 120V DIN B-SER [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.3000
- Volt-Amp Rating: 0.5000
- Full Load Runtime: 4.3
from DigiKey
OFF-LINE UPS 850VA 120V [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.5100
- Volt-Amp Rating: 0.8500
- Full Load Runtime: 2.5
from DigiKey
UPS PRO, 30W 100VA DIECAST ENCLO [See More]
- Technology: Off-line (Standby)
- Input Voltage Range: 57
- Watt Rating: 0.0300
from DigiKey
UPS PRO, 100W 200VA, 12VDC 20A U [See More]
- Technology: Off-line (Standby)
- Input Voltage Range: 120 to 240
- Watt Rating: 0.1200
- Standards / Compliance: CE, UL
from DigiKey
UPS PRO, 30W 200VA POLYCARBONATE [See More]
- Technology: Off-line (Standby)
- Input Voltage Range: 57
- Watt Rating: 0.0300
from DigiKey
UPS 18.5VDC 1.4AH DIN RAIL [See More]
- Technology: Off-line (Standby)
- Standards / Compliance: RoHS Compliant
- Mounting Options: Din Rail
from Tripp Lite by Eaton
Features. Compact Desktop 500VA/260W Battery Backup for PCs, Home Theater and Digital SignageThis 120V UPS system provides reliable battery backup and AC power protection against blackouts, brownouts, overvoltages, surges and line noise that can damage valuable electronics or destroy data. The... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.2600
- Volt-Amp Rating: 0.5000
- Half Load Runtime: 6.9
from ZTE Corporation
ZXUPSE X500 is an on-line double conversion modular UPS system with three-phase input and three-phase output. This modular UPS system is scalable from 50 kVA to 500 kVA, which is composed of 50 kVA power units (PU) to offer flexible options. The series is widely used in government, finance,... [See More]
- Technology: Off-line (Standby)
- Mounting Options: Tower Type
- Input Voltage Range: 130 to 275
- Interfaces: Ethernet
from Powerstar UPS Inc.
Power strip/ Shipboard 550VA /330W UPS and Surge suppressor Brick shaped (88x180x302mm Deep) No fans, silent in operation. High impact resistant case. 4 surge protected outlets and 4 more UPS /surge outlets. Dual pole input breaker protects both sides of the line for shock protection. Also includes... [See More]
- Technology: Off-line (Standby); Surge Suppressor and Stepped Sine UPS
- Watt Rating: 0.0100 to 0.3300
- Volt-Amp Rating: 0.0 to 0.5500
- Half Load Runtime: 0.0 to 13
from Eaton | Power Quality
The sleek, savvy and sophisticated 3S delivers premium battery backup and surge protection for up to 10 home and office devices. EcoControl functionality provides up to 30 percent greater energy savings than typical battery backups, and plug-and-play compatibility enables automatic integration. The... [See More]
- Technology: Off-line (Standby)
- Half Load Runtime: 11
- Volt-Amp Rating: 0.3500 to 0.7000
- Full Load Runtime: 2
from Tripp Lite by Eaton
Tripp Lite's BCPERS300 standby UPS offers AC surge suppression and long lasting battery support for desktop PCs, network workstations and a wide variety of consumer and electronic devices. Uninterruptible Power Supply / UPS circuits switch to battery backup mode within milliseconds to keep connected... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.1800
- Volt-Amp Rating: 0.3000
- Half Load Runtime: 16.8
from ZTE Corporation
ZXUPSE Q200 is an on-line double conversion modular UPS system with three-phase input and three-phase output. This modular UPS system is scalable from 20 kVA to 200 kVA, which is composed of 20 kVA power units (PU) to offer flexible options. The series is widely used in government, finance,... [See More]
- Technology: Off-line (Standby)
- Mounting Options: Tower Type
- Input Voltage Range: 130 to 275
- Interfaces: Ethernet
from Eaton | Power Quality
The small, compact Eaton 5S UPS delivers backup power for desktop PCs and workstations. The Eco-Control capability of this small UPS enables you save up to 30 percent in energy consumption. You can also enhance your power protection and safeguard your data when you pair it with the Eaton UPS... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.3300 to 0.9000
- Volt-Amp Rating: 0.5500 to 1.5
- Input Voltage Range: 120 to 230
from Tripp Lite by Eaton
Tripp Lite's BC350 standby UPS offers power protection for PCs, workstations and other sensitive electronics in an attractive space saving, ultra-compact housing. Prevents data loss and system downtime by providing battery-supported AC output during brownouts and blackout conditions. 6 widely spaced... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.1800
- Volt-Amp Rating: 0.3500
- Half Load Runtime: 12
from ZTE Corporation
ZXUPSR S series is small power capacity rack-mounted UPS, adopting new digital control technology. This on-line double conversion UPS system is built in 19 inch rack and available in 1 kVA~10 kVA capacity, providing high reliable and high performance power protection. The system supplies with a... [See More]
- Technology: Off-line (Standby)
- Mounting Options: Rack or Tray
- Input Voltage Range: 110 to 300
- Interfaces: Serial; Ethernet
from Tripp Lite by Eaton
Tripp Lite's BCPERS450 standby UPS offers AC surge suppression and long lasting battery support for desktop PCs, network workstations and a wide variety of consumer and professional electronics. Uninterruptible Power Supply / UPS circuits switch to battery backup mode within milliseconds to keep... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.2800
- Volt-Amp Rating: 0.4500
- Half Load Runtime: 15
from ZTE Corporation
ZXUPS T series UPS has an advantage of leading product performance and operating reliability with high input power factor, conversion efficiency and low input current distortion rate. The series is widely used in government, finance, telecommunications, education, transportation, meteorology, radio... [See More]
- Technology: Off-line (Standby)
- Mounting Options: Tower Type
- Input Voltage Range: 132 to 275
from Tripp Lite by Eaton
Tripp Lite's BCPRO1050 standby UPS offers AC surge suppression and long lasting battery support for desktop PCs, network workstations and a wide variety of consumer and professional electronics. Uninterruptible Power Supply / UPS circuits switch to battery backup mode within milliseconds to keep... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.7050
- Volt-Amp Rating: 1.05
- Half Load Runtime: 23
from Tripp Lite by Eaton
Tripp Lite's BCPRO1400 standby UPS offers AC surge suppression and long lasting battery support for desktop PCs, network workstations and a wide variety of consumer and professional electronics. Uninterruptible Power Supply / UPS circuits switch to battery backup mode within milliseconds to keep... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.9400
- Volt-Amp Rating: 1.4
- Half Load Runtime: 24
from Tripp Lite by Eaton
Tripp Lite's BCPRO600 standby UPS offers complete power protection for desktop PCs, network workstations and a wide variety of consumer and professional electronics. Uninterruptible Power Supply / UPS circuits switch to battery backup mode within milliseconds to keep connected equipment running... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.3450
- Volt-Amp Rating: 0.6000
- Half Load Runtime: 14.5
from Tripp Lite by Eaton
The ECO350UPS standby green UPS offers complete protection from blackouts, brownouts and transient surges. Supports green energy savings via built-in Eco outlets that automatically power off unused computer accessories like printers or multi-media speakers when the computer is not in use. Full load... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.1800
- Volt-Amp Rating: 0.3500
- Half Load Runtime: 11.3
from Tripp Lite by Eaton
The ECO550UPS standby green UPS offers complete protection from blackouts, brownouts and transient surges. Supports green energy savings via built-in Eco outlets that automatically power off unused computer accessories like printers or multi-media speakers when the computer is not in use. Full load... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.3000
- Volt-Amp Rating: 0.5500
- Half Load Runtime: 10
from Tripp Lite by Eaton
The ECO650LCD ultra-compact green UPS offers complete protection from blackouts, voltage fluctuations and transient surges. Interactive LCD user interface offers detailed UPS and site electrical data, including input/output voltage, estimated runtime remaining, load percentage, load wattage and... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.3250
- Volt-Amp Rating: 0.6500
- Half Load Runtime: 5.3
from Tripp Lite by Eaton
The ECO650UPSM standby green UPS offers complete protection from blackouts, brownouts and transient surges. Supports green energy savings via built-in Eco outlets that automatically power off unused computer accessories like printers or multi-media speakers when the computer is not in use. Full load... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.3250
- Volt-Amp Rating: 0.6500
- Half Load Runtime: 11
from Tripp Lite by Eaton
The ECO750UPS standby green UPS offers complete protection from blackouts, brownouts and transient surges. Supports green energy savings via built-in Eco outlets that automatically power off unused computer accessories like printers or multi-media speakers when the computer is not in use. Full load... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.4500
- Volt-Amp Rating: 0.7500
- Half Load Runtime: 9.4
from Tripp Lite by Eaton
The ECO850LCD ultra-compact green UPS offers complete protection from blackouts, voltage fluctuations and transient surges. Interactive LCD user interface offers detailed UPS and site electrical data, including input/output voltage, estimated runtime remaining, load percentage, load wattage and... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.4250
- Volt-Amp Rating: 0.8500
- Half Load Runtime: 13.4
from Tripp Lite by Eaton
The ECO9000UPSM standby green UPS offers complete protection from blackouts, brownouts and transient surges. Supports green energy savings via built-in Eco outlets that automatically power off unused computer accessories like printers or multi-media speakers when the computer is not in use. Full... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.4800
- Volt-Amp Rating: 0.9000
- Half Load Runtime: 9.2
from Tripp Lite by Eaton
The INTERNET350SER Internet Office ® 120V 350VA 180W Standby UPS protects your PC and other expensive equipment against common power threats, such as blackouts and surges. Reliable battery backup support allows you to work through short power failures, and gives you enough time to safely save... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.1800
- Volt-Amp Rating: 0.3500
- Half Load Runtime: 12.2
from Tripp Lite by Eaton
Tripp Lite's INTERNET350U standby UPS system offers complete protection from blackouts, brownouts and transient surges on both AC and dialup modem lines. Provides seamless battery support during brownouts and power failures with enough runtime to save and shutdown connected equipment without data... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.1800
- Volt-Amp Rating: 0.3500
- Half Load Runtime: 11.3
from Tripp Lite by Eaton
Tripp Lite's INTERNETOFFICE300 UPS System provides complete power protection for your entire computer set-up. 300 VA power capacity maintains your Internet connection allowing you to work online through short blackouts or safely shut down during longer ones. Unique design features 6 outlets (3 UPS... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.1500
- Volt-Amp Rating: 0.3000
- Half Load Runtime: 10
from Tripp Lite by Eaton
Tripp Lite's INTERNETOFFICE500 standby UPS system offers surge suppression and long-lasting battery support for personal computers, internetworking equipment and other sensitive electronics. Internal UPS circuits support entry-level PC systems for up to 30 minutes during power failures and brownouts... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.2800
- Volt-Amp Rating: 0.5000
- Half Load Runtime: 14.8
from Tripp Lite by Eaton
Ultra-compact standby UPS with DB9 serial monitoring protects PCs, network workstations and other systems reliant upon a simple serial communications interface for UPS monitoring and unattended system shutdown. Maintains AC output during blackouts and brownouts starting at 99V. Includes DB9... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.3000
- Volt-Amp Rating: 0.5500
- Half Load Runtime: 6
from Tripp Lite by Eaton
Tripp Lite's INTERNET550U standby UPS offers complete protection for PCs, workstations and other sensitive electronics in an attractive ultra-compact, mountable housing. Prevents data loss and system downtime by providing battery supported AC output during brownouts and blackout conditions. 8 output... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.3000
- Volt-Amp Rating: 0.5500
- Half Load Runtime: 5.6
from Tripp Lite by Eaton
Ultra-compact standby UPS with built-in USB monitoring protects PCs, network workstations and other systems reliant upon a USB interface for UPS monitoring and unattended system shutdown. Maintains AC output during blackouts and brownouts starting at 99V. Includes USB monitoring with cabling,... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.3000
- Volt-Amp Rating: 0.6000
- Half Load Runtime: 9.9
from Tripp Lite by Eaton
Features. Compact Desktop 650VA/330W Battery Backup for PCs, Home Theater and Digital SignageThis 120V UPS system provides reliable battery backup and AC power protection against blackouts, brownouts, overvoltages, surges and line noise that can damage valuable electronics or destroy data. The... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.3300
- Volt-Amp Rating: 0.6500
- Half Load Runtime: 4.5
from Tripp Lite by Eaton
Tripp Lite's INTERNETOFFICE700 standby UPS system offers surge suppression and long-lasting battery support for personal computers, internetworking equipment and other sensitive electronics. Internal UPS circuits support entry-level PC systems for up to 45 minutes during power failures and brownouts... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.4250
- Volt-Amp Rating: 0.7000
- Half Load Runtime: 11.2
from Tripp Lite by Eaton
Tripp Lite's INTERNET750U standby UPS offers complete protection for PCs, workstations and other sensitive electronics in an attractive, ultra-compact, mountable housing. Prevents data loss and system downtime by providing battery-supported AC output during brownouts and blackouts. 12 widely spaced... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.4500
- Volt-Amp Rating: 0.7500
- Half Load Runtime: 9.4
from Tripp Lite by Eaton
Tripp Lite's INTERNET900U standby UPS offers complete protection for PCs, workstations and other sensitive electronics in an attractive, ultra-compact, mountable housing. Prevents data loss and system downtime by providing battery-supported AC output during brownouts and blackouts. 12 widely spaced... [See More]
- Technology: Off-line (Standby)
- Watt Rating: 0.4800
- Volt-Amp Rating: 0.9000
- Half Load Runtime: 8.2