Specifications : Output Max Configurable Power (Watts) 6.0kWatts / 6.0kVA Output Voltage Note Configurable for 220 : 230 or 240 nominal output voltage Efficiency at Full Load 94.0 % Output Voltage Distortion 1 % Output Frequency (sync to mains) 50/60 Hz +/- 3 Hz Sync to mains Other Output Voltages 220 V, 240 V Load Crest Factor 3 : 1 Topology Double conversion online Waveform type Sine wave Bypass Internal bypass (automatic and manual) Input Input frequency 40 – 70 Hz Auto sensing Input voltage range for main operations 110 – 300 Half load, 176 – 300 Full loadV Efficiency at Full Load 94.0 % Other Input Voltages 220 V, 240 V Batteries & Runtime Battery type Lead-acid battery Typical recharge time 7hour(s) Nominal Battery Voltage 192 V Expected Battery Life (years) 3 – 5 Battery Charge Power (Watts) 235 Watts Runtime View Runtime Graph Communications & Management Interface Port(s) DB-9 RS-232, USB Control panel Multifunction LCD status and control console Audible Alarm Alarm when on battery : distinctive low battery alarm : overload continuous tone alarm Emergency Power Off (EPO) Yes Available SmartSlot™ Interface Quantity 1 Surge Protection and Filtering Surge energy rating 600Joules Physical Maximum Height 173MM, 17.3CM Maximum Width 438MM, 43.8CM Maximum Depth 710MM, 71.0CM Net Weight 61.0KG Shipping weight 71.0KG Shipping Height 1232MM, 123.19CM Shipping Width 600MM, 60.0CM Shipping Depth 836MM, 83.6CM Color Black Environmental Operating Temperature 0 – 40 °C Operating Relative Humidity 0 – 95 % Operating Elevation 0 – 3000meters Storage Temperature -15 – 60 °C Storage Relative Humidity 0 – 95 (Non-condensing) % Storage Elevation 0 – 15000meters Audible noise at 1 meter from surface of unit 55.0dBA Online thermal dissipation 1172.0BTU/hr Protection Class IP20 Conformance Approvals CE, EAC, EN/IEC 62040-1, EN/IEC 62040-2, TISI Standard warranty 2 years repair or replace Sustainable Offer Status RoHS Compliant Warranty : 1 year https://www.apc.com/shop/dk/en/products/APC-Easy-UPS-On-Line-SRV-6000VA-RM-230V-with-Rail-Kit/P-SRV6KRIRK
APC 800VA BX800LI 415W UPS (IEC Plug) APC 650VA BX650LI UPS
APC Easy UPS On-Line SRV 3000VA 230V SRV3KI is a high-performance uninterruptible power supply designed to provide continuous power protection for servers, network equipment, data centers, and critical business systems. It uses true online double-conversion technology to deliver clean and stable power in demanding environments. The UPS provides 3000VA / 2400W power capacity. Therefore, it can support critical equipment during power outages, voltage fluctuations, and electrical disturbances. In addition, it helps maintain business continuity and equipment reliability. It features online double-conversion technology that continuously conditions incoming power. As a result, connected devices receive consistent and clean power regardless of utility power quality. The unit includes an LCD display for real-time monitoring and system management. Meanwhile, automatic bypass functionality helps maintain power delivery during specific operating conditions and maintenance events. APC designs the Easy UPS On-Line series for dependable power protection and efficient operation. Therefore, this model is ideal for servers, network infrastructure, security systems, and mission-critical applications. manufacturer link Specifications: 3000VA / 2400W power capacity Online double-conversion technology Pure sine wave output LCD status and monitoring display Reliable backup for critical systems
PCE VX Online 1 KVA 800W Internal Batteries Double Conversion Online- Pure Sine Wave Model VX 1K Input Rating Voltage Frequency Voltage range Power Factor THDi 1000VA 220V, 230V, 240V, 1Ø 2Wires 40~70Hz 176-300 VAC at 100% load, 110-300 VAC at 50% load >99% <5% Ouput Active Power @ PF=0.9 Voltage (on battery) Frequency (on battery) Transfer Time Efficiency UPS Design Technology Output Wave Form Total Harmonic distortion (THD) Crest Factor 900W 220V, 230V, 240V, +/-1% (selectable output voltage), 1Ø 2Wires 50/60 Hz +/-0.2% 0 ms 93% Online double conversion design Pure Sinewave ≤3% (linear load), ≤5% (non linear load) 3:1 Protection Overload Protection Short Circuit Protection 110% for 10min, 130% for 1min, >130% for 3sec UPS output cuts off immediately using input fuse/circuit breaker protection System Display LCD indicators Load level, Battery level, AC mode, Battery mode, Bypass mode, and Fault indicators Alarm Battery mode Low battery Overload Fault Sounding every 4 second Sounding every second Sounding twice every second Continuously sounding Battery Battery Type Typical Recharge Time DC Voltage Charging Current Back up time(1/2 Load) 12V 9Ah 4 hours to 90% Full capacity 24VDC 1A 10~15 min depending on load Communication USB or RS-232 SNMP* Compatibility Interface with power management software Power Management from SNMP manager and web browser Supports Windows family, Linux, Unix and Mac Physical W x D x H mm Net Weight Kgs(lbs) 145x282x220mm 9.8Kg(21.6lb) Environment Operating Temperature Storage Temperature Altitude Audible noise Relative Humidity 0 – 40 °C / 32 ~ 104°F -20 ~ 50°C / -4 ~ 122°F 1,500 meters max <50dBA at 1 Meter 20 to 90% humidity (non-condensing) Standards & Certifications Performance Safety EMC (EMS / EMI) Design, production, & services Environment Marking & Certifications EN50091-3/IEC 62040-3 UL 1778, CE, EN 50091-1,EN 60950 (RD/), IEC 60950 IEC 61000-4-2/-3/-4/-5/-6/-8/-11, IEC 61000-3-2/-3,FCC Part 15, CISPR 22, EN 50091-2/IEC62040-2 Class A, EN 55022/B,FCC 47 part 15 – Subpart B – ISO 9001 ISO 14001 certified company CE, TUV/GS, UL, cUL, c-Tick
MARSRIVA SMART MINI DC UPS 10000MAH Capacity: 10000mAh / 37Wh. Output Interface: USB-A Output: 5V at 2.4A, DC Output: 5V / 9V / 12V (selectable) at 1.5A, POE Output: 5V at 2.4A. Dimensions: 104.5 x 170 x 30.8 mm. Net Weight: 360g. Color: Black. Specifications: MARSRIVA SMART MINI DC UPS 10000MAH Capacity: 10000mAh / 37Wh. Output Interface: USB-A Output: 5V at 2.4A, DC Output: 5V / 9V / 12V (selectable) at 1.5A, POE Output: 5V at 2.4A. Dimensions: 104.5 x 170 x 30.8 mm. Net Weight: 360g. Color: White.
The Twist Online High Frequency UPS 3KVA TWUP3000/HF delivers reliable backup power for servers, networking systems, and professional equipment. It uses online double conversion technology for continuous clean power output. Additionally, the high-frequency design improves efficiency and reduces power interruption risks. Moreover, the UPS includes an LCD display for real-time system monitoring and status alerts. It features internal 6x12V/9Ah batteries for backup operation during outages. Therefore, it helps protect sensitive devices from voltage fluctuations and sudden power loss. Furthermore, the TWUP3000/HF supports pure sine wave output for stable performance with critical equipment. It also includes overload, short-circuit, and overheating protection for safer operation. Additionally, the compact tower design fits office, server room, and IT environments easily. Specifications: 3KVA online double conversion UPS technology Internal 6x12V/9Ah rechargeable batteries LCD display for real-time monitoring Pure sine wave output for stable power delivery Overload and short-circuit protection system
Key Features Output Connections (1) IEC 60320 C19 Input Connections Schuko CEE 7 / EU1-16P Cord Length 8.2ft (2.5meters) Power Cord, C19 to CEE/7 Schuko, 2.5m Wide selection of Rack PDU power cords for a variety of IT equipment. Specifications : Output Overload Protection No Maximum Total Current Draw 16 Input Input frequency 50/60 Hz Acceptable Input Voltage 90 – 250VAC Number of Power Cords 1 Maximum Input Current 16A Maximum Line Current 16A Physical Net Weight 0.49lbs. (0.22KG) Shipping weight 0.66lbs. (0.3KG) Shipping Height 2.01inches (51MM, 5.1CM) Shipping Width 4.02inches (102MM, 10.2CM) Shipping Depth 7.99inches (203MM, 20.3CM) Color Black Environmental Operating Temperature 32 – 113 °F (0 – 45 °C) Operating Relative Humidity 0 – 95 % Operating Elevation 0 – 10000ft (0 – 3048meters) Storage Temperature -25 – 65 °C Storage Relative Humidity 0 – 95 % Storage Elevation 0 – 50000ft (0 – 15240meters) manufacturer link
APC UPS Accessories SURT48XLBP APC Smart-UPS RT 48V 1/2KVA SURT models Battery Pack
The Beco GP1200 1200VA 720W UPS delivers reliable power backup for home and office electronics. It keeps key devices running during outages. This helps prevent data loss and sudden shutdowns. Users gain peace of mind knowing devices stay protected. Moreover, the Beco GP1200 1200VA 720W UPS features 1200 VA capacity and 720 W output power for strong support. It handles computers, routers, modems, and monitors easily. Large systems stay powered long enough to save work. Performance stays stable and secure. In addition, the UPS includes built-in surge protection for reliable defense against voltage spikes. It guards appliances from unstable power conditions and electrical surges. This adds extra safety during storms or fluctuations. Protection stays consistent over time. Furthermore, the Beco GP1200 1200VA 720W UPS offers automatic voltage regulation without manual settings. It smooths voltage drops and spikes quickly. This helps connected devices run smoothly. Reliability increases in daily use. Also, the UPS provides battery backup when power fails. You can finish tasks and save important files before turning off systems. This reduces the risk of data corruption. Backup power feels dependable. In addition, the Beco GP1200 1200VA 720W UPS includes clear LED indicators for power and battery status. You can check performance at a glance. This helps monitor conditions with ease. Users stay informed during operation. Moreover, the UPS includes multiple output sockets for connecting more devices at once. This improves flexibility for busy workstations and entertainment setups. You can protect multiple electronics with one unit. Furthermore, the Beco GP1200 1200VA 720W UPS supports easy installation and quick setup. Users can connect devices without complicated steps. Setup remains simple for all users. Also, the compact design fits neatly on desks, shelves, or cabinets without taking much room. It blends well into home and office spaces. Portability stays practical. Overall, the Beco GP1200 1200VA 720W UPS delivers strong battery backup, surge protection, and smooth voltage regulation. It guards electronics and ensures uninterrupted use. This UPS is ideal for users seeking reliable, everyday power protection. Specifications: 1200VA, 720W, LED, Plastic Case Input: 140-290 VAC Output: 230VAC 50/60HZ 12V 7.5AH *2pcs, Universal Socket *4 + EU Plug With AVR, Bypass output Overload and short circuit protection
The Beco GP1500 1500VA 900W UPS delivers strong and reliable power protection for home and office electronics. It keeps computers, routers, and monitors running during outages. This helps prevent data loss and sudden shutdowns. Peace of mind increases with reliable backup power. Moreover, the Beco GP1500 1500VA 900W UPS offers 1500 VA capacity and 900 W output for high-demand systems. It supports larger desktops and entertainment setups easily. Backup power stays strong during interruptions. This improves system stability every day. In addition, the UPS features built-in surge protection to guard appliances from spikes and unstable power. This adds important defense against electrical damage. Devices remain safe during storms and fluctuations. Safety stays consistent. Furthermore, the Beco GP1500 1500VA 900W UPS includes automatic voltage regulation to smooth dips and spikes. It balances voltage without manual adjustment. This helps extend device lifespan. Consistent power improves performance. Also, the UPS delivers dependable battery backup when electricity fails. You can save files and shut down properly before power runs out. This reduces the risk of data loss. Backup support feels reassuring. In addition, the Beco GP1500 1500VA 900W UPS has clear LED indicators for power and battery status. You can check conditions easily at a glance. This makes monitoring simple and fast. Moreover, the UPS includes multiple output sockets for connecting several devices at once. This increases flexibility for busy workstations and entertainment centers. You can protect all critical electronics with one unit. Furthermore, the Beco GP1500 1500VA 900W UPS supports quick plug-and-play setup with no complex steps. Installation feels easy for any user. Setup remains fast and hassle-free. Also, the compact and sturdy design fits neatly into workspaces or shelves. It blends well into home and office environments. Portability stays practical. Overall, the Beco GP1500 1500VA 900W UPS delivers strong battery backup, surge protection, and voltage regulation. It ensures steady power and protects electronics effectively. This UPS is ideal for users needing reliable, high-capacity power protection every day. Specifications: 1500VA, 900W, LED, Plastic Case Input: 140-290 VAC Output: 230VAC 50/60HZ 12V 9AH *2pcs, Universal Socket *4 + EU Plug With AVR, Bypass output Overload and short circuit protection
Specifications : -True Double-Conversion Online UPS – Mircoprocessor control optimizes reliability – Input power factor correction – Output Power Factor 0.80. – Wide input voltage (110V – 300V) – Converter mode available – ECO mode for enegry saving (Only available for 1 – 3 KVA) – Generator compatible – Adjustable battery number only available for 6K and up models – Smart SNMP works well with either USB or RS-232 together – Emergency power off function (EPO) only available for 6K / 10K models – Optional isolation transformer available. manufacturer link
APC UPS Accessories SURTRK APC Smart-UPS RT 19″ Rail Kit 1 – 2.2KVA
The Beco GP600 600VA 360W UPS delivers reliable power protection for home and office devices. It keeps your electronics safe during outages and voltage drops. This UPS helps prevent data loss and sudden shutdowns, providing peace of mind every day. Moreover, the Beco GP600 600VA 360W UPS features 600 VA capacity with up to 360 W output power. It supports computers, routers, modems, and monitors effortlessly. Devices continue running smoothly during short power interruptions. This improves system stability. In addition, the UPS includes built-in surge protection for safe operation. It guards connected devices against spikes and surges. This adds an extra layer of defense during storms or unstable power conditions. Safety remains a priority. Furthermore, the Beco GP600 600VA 360W UPS offers battery backup that keeps equipment running long enough to save work. This prevents data corruption during sudden outages. Users can shut down systems properly. Protection feels dependable. Also, the unit delivers stable voltage regulation without manual adjustment. It corrects fluctuations automatically. This improves device performance and lifespan. Steady power enhances everyday use. In addition, the Beco GP600 600VA 360W UPS includes easy-to-read LED indicators. They show power and battery status at a glance. Users stay informed without confusion. Monitoring becomes simple and quick. Moreover, the UPS features multiple outlets for connecting several devices at once. This increases flexibility for workstations and entertainment setups. You can protect more devices with one unit. Furthermore, the Beco GP600 600VA 360W UPS supports simple installation without complicated steps. Setup is quick with clearly marked connections. This helps both beginners and experienced users. Also, the compact design fits well on desks or shelves without taking much space. It blends into home and office environments easily. Portability stays practical. Overall, the Beco GP600 600VA 360W UPS delivers dependable battery backup, surge protection, and steady power. It protects vital electronics and supports uninterrupted use. This UPS is ideal for users seeking reliable power protection every day. Specifications: 600VA, 360W, LED, Plastic Case Input: 145-290 VAC Output: 230VAC 50/60HZ 12V 7AH *1pc, Universal Socket *2 + EU Plug With AVR, Bypass output Overload and short circuit protection
The Prosonic 2000mAh MINI DC UPS | GS-1018 provides stable backup power for routers, modems, CCTV cameras, ONU devices, and other low-power networking equipment during electricity outages. Its compact design fits easily beside networking devices while maintaining reliable operation for home and office setups. This mini UPS supports multiple DC output options, making it suitable for different electronic devices that require continuous power. The built-in safety protections help prevent overheating, overload, overcharging, and short circuits, which improves long-term reliability and device safety. In addition, the lightweight body allows easy placement in small spaces without adding clutter to your setup. The unit delivers dependable backup support for internet connectivity during load shedding or sudden power interruptions. Users can connect routers and communication equipment directly to maintain stable online access for work, streaming, online classes, or security monitoring systems. Key operating features include efficient power conversion, portable dimensions, and compatibility with common DC-powered devices. The Prosonic GS-1018 also offers a practical solution for users who need uninterrupted networking performance without using a large traditional UPS system. Moreover, the compact battery backup system helps reduce downtime while protecting connected devices from sudden shutdowns. Its easy plug-and-play setup makes installation simple for both home and small business users. Specifications: 2000mAh backup battery capacity for networking devices Supports routers, CCTV cameras, modems, and ONU devices Multiple DC output options for wider compatibility Built-in overload, short circuit, and overcharge protection INPUT : 100-240Vac 50/60Hz OUTPUT : 5V/9V/12V/USB port/POE port
The Beco GP800 800VA 480W UPS delivers dependable power protection for home and office electronics. It keeps devices running during short power cuts. This helps prevent data loss and sudden shutdowns. Users enjoy peace of mind with reliable backup power. Moreover, the Beco GP800 UPS features 800 VA capacity and 480 W output power for stronger protection. It supports desktops, routers, modems, and monitors easily. Devices stay powered long enough to save work. Performance remains stable. In addition, the UPS includes built-in surge protection for safety against spikes. It guards appliances from voltage surges and unstable power conditions. This adds extra defense during storms or power fluctuations. Protection stays consistent. Furthermore, the Beco GP800 800VA 480W UPS offers automatic voltage regulation without manual adjustment. It corrects voltage dips and spikes smoothly. This helps maintain steady performance for connected devices. Reliability improves everyday use. Also, the unit provides battery backup during outages to keep systems running. You can finish tasks and save files before shutdown. This reduces the risk of data corruption. Battery backup feels dependable. In addition, the Beco GP800 UPS includes clear LED indicators for power and battery status. You can check conditions at a glance. This makes monitoring simple and fast. Users stay informed. Furthermore, the Beco GP800 UPS supports easy installation and setup. Users can plug in devices quickly without complicated steps. Setup remains stress-free for beginners and experts. Overall, the Beco GP800 800VA 480W UPS delivers reliable battery backup, surge protection, and stable power output. It protects electronics and supports uninterrupted use. This UPS is ideal for users seeking strong, everyday power protection. Specifications: 800VA, 480W, LED, Plastic Case Input: 140-290 VAC Output: 230VAC 50/60HZ 12V 9AH *1pc, Universal Socket *2 + EU Plug With AVR, Bypass output Overload and short circuit protection
Aokly Gel Battery 12V – 200A 58.5Kg manufacturer link
INVO Online INH100 INVO Online INH100 Centralized server center, mainframe, network control center, computing center max efficiency UPS System . AC Input Bypass AC Output . Battery Fault Screen OFF ON LCD AC Input Bypass AC Output Battery Fault Screen OFF ON LCD INVO Online INH100 Full Specifications : INVO Online INH100 Centralized server center, mainframe, network control center, computing center INVO Online INH100 UPS High Frequency 1000 VA, LCD Display Inbuilt Battery 2 x 12V/9AH Specifications: Specifications : Centralized server center, mainframe, network control center, computing center INVO Online UPS High Frequency 1000 VA, LCD Display Inbuilt Battery 2 x 12V/9AH 1 year warranty Manufacturer Link
General Topology Online double conversion Configuration Tower Part Number 9E1000I Rating (VA/Watts) 1000/800 Dimensions (H x W x D, mm) 356 x 228 x 144 Weight (kg) 9.5 Electrical Input Connection (1) IEC-320-C14 Input Voltage Range 176-300V without derating (up to 100-300V with derating) Nominal Voltage 208/220/230/240V Frequency 50/60 Hz autoselection Frequency Range 40-70 Hz Electrical Output Voltages 208V*/220V/230V/240V ±1% Voltage THD <2% for 100% linear load Outlets (4) IEC-320-C13 Overload Capacity 105%-130% : 60s, 130%-150% : 10s,>150% : ≥ 300ms Efficiency (Normal Mode) Up to 91% in Online mode Output Frequency 50/60 Hz autoselect Communications Communication Ports 1 USB port + 1 RS232 serial port (USB and RS232 ports cannot be used simultaneously) Communication Slot 1 slot for Network-M2, ModBus-MS or Relay-MS cards Power Management Software Intelligent Power Editions Environmental & Standards Audible Noise <37 dB @ typical load Operating Temperature 0 to 40°C Safety markings IEC/EN 62040-1 EMC Markings IEC/EN 62040 -2 Approvals CE, CB report (TUV) 2 Years Warranty manufacturer link
INVO online INH1000 NVO Online UPS High Frequency 10000 VA, LCD Display Inbuilt Battery 16 x 12V/9 Ah Specifications: Specifications : AC Input Bypass AC Output Battery Fault Screen LCD AC Input Bypass AC Output Battery Fault Screen LCD 1 year warranty Manufacturer Link
Original product name: UPS 5E650IUSBDIN Eaton Line Interactive UPS 650VA / 360W, AVR, 1 Schuko (DIN) + 2 IEC, USB port, software, Input / Output jacks included for Telephone / Modem / Internet Line surge protection, 2 Years Warranty (Including Battery) 5E650IUSBDIN Eaton Line Interactive UPS 650VA / 360W, AVR, 1 Schuko (DIN) + 2 IEC, USB port, software, Input / Output jacks included for Telephone / Modem / Internet Line surge protection 2 Years Warranty (Including Battery)
Specifications : High Reliability Advanced DSP (Digital signal processors) technology Variable speed fan Effective software and hardware protection function, robust self-diagnostic function, and abundant event log for check Advanced digital parallel technology High Availability Wide input voltage range, 50 / 60 Hz frequency auto sensing Linear derating in low voltage input reducing battery discharging times, extending the service life of battery Dual-input design, supporting independent bypass Output power factor improved from 0.9 to 1, load capacity increased by 13% Flexible battery configuration (settable 16 – 20 pcs batteries) Charging voltage and current configured by demands Ability to switch on the UPS with batteries Settable delayed start time when mains power is restored, reducing the impact on power grid or generator Two modes of frequency conversion: 50 Hz input / 60 Hz output or 60 Hz input / 50 Hz output High Usability LCD+LED display, multi-functional keys operation, friendly human-machine interface Powerful background software for parameters configuration and online updating Compact internal layout, miniaturized the complete unit for small footprint High Intelligence Advanced multi-platform communications: RS232, USB, RS485, SNMP and dry contacts communication interfaces Intelligent battery management, automatic floating / equalizing charge control, charger dormancy control, increasing battery life by 50% Energy Conservation and Environment Protection Active power factor correction (APFC), input power factor up to 0.99 High efficiency 95% (up to 98% in ECO mode) Automatic power On/Off according to the load capacity set by users Equipped with self-aging function
Specifications : GENERAL Rated Power 5000VA / 5000W Communication Interface Removable USB / RS232 / RS485 / Bluetooth / Dry-contact Dimension D x W x H (mm) 115 x 300 x 400 Net Weight (kgs) 13 INPUT Voltage 230VAC Selectable Voltage Range 170 ~ 280 VAC (For Personal Computers)90 ~ 280 VAC (For Home Appliances) Frequency Range 50Hz / 60Hz (Auto sensing) OUTPUT AC Voltage Regulation (Batt. Mode) 230VAC ± 5% Surge Power 10000VA Efficiency (Peak) 90% ~ 93% Transfer Time 15 ms (For Personal Computers)20 ms (For Home Appliances) Waveform Pure sine wave BATTERY Battery Voltage 48VDC Floating Charge Voltage 54VDC Overcharge Protection 63VDC SOLAR & AC CHARGER Solar Charger Type MPPT Maximum PV Array Open Circuit Voltage 500VDC Maximum PV Array Power 5000W MPP Range @ Operating Voltage 120VDC~450VDC Maxmum Solar Charge Current 100A Maximum AC Charge Current 100A manufacturer link
Prolink PRO906WS 6KVA / 4800W Online UPS with AVR is a high-performance power backup solution designed for critical devices, servers, and sensitive electronics. It provides stable and continuous power protection against outages and voltage fluctuations. It features a 6000VA (4800W) capacity with pure sine wave output. Therefore, it ensures clean and reliable power delivery for computers, networking equipment, and industrial systems. In addition, it protects devices from sudden power loss and electrical damage. The UPS uses online double-conversion technology with built-in AVR (Automatic Voltage Regulation). As a result, it delivers consistent voltage output and improves equipment safety during unstable power conditions. It supports heavy-duty usage and long backup operation depending on load. Meanwhile, its robust design makes it suitable for business, IT infrastructure, and professional environments. Prolink designs its UPS systems for reliability and protection. Therefore, this model is an ideal choice for users who need uninterrupted and stable power supply for critical operations. manufacturer link Specifications: 6000VA / 4800W high capacity Pure sine wave output Online double-conversion UPS Built-in AVR voltage regulation Ideal for servers and critical systems