The PROLINK PRO1501SFCU Super Fast Charging UPS is designed to provide reliable backup power and voltage protection for computers, networking equipment, gaming systems, and office electronics. It helps keep essential devices operating during power interruptions and unstable electrical conditions. The UPS provides a 1500VA capacity and uses line interactive technology with Automatic Voltage Regulation (AVR). Additionally, AVR helps stabilize input voltage fluctuations and delivers safer power to connected devices. The PROLINK PRO1501SFCU features super-fast charging technology that significantly reduces battery recharge time after a power outage. Moreover, this feature ensures the UPS becomes ready for the next interruption more quickly. The UPS includes multiple protection functions against overload, short circuit, surge, and battery discharge conditions. Furthermore, these protection features help improve the safety and reliability of connected equipment. The PROLINK PRO1501SFCU includes LED status indicators and audible alarms for easier system monitoring. Therefore, users can quickly check operating conditions and power status during daily use. The compact design makes the UPS suitable for homes, offices, and small business environments. In addition, it provides dependable backup support for desktop PCs, routers, NAS devices, and CCTV systems. The PROLINK PRO1501SFCU Super Fast Charging UPS combines backup power, rapid battery charging, AVR technology, and advanced protection features. As a result, it provides a practical and reliable power protection solution for everyday applications. Specifications: Capacity : 1500VA Input : 140-230VAC Output : 230VAC Transfer Time : 2ms Battery Type : 12V Backup Time : 40 Min (Depending on the load) Part Number : PRO1501SFCU
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
The PROLINK IPS5003 Inverter is designed to provide reliable backup power for homes, offices, and essential electronic devices. It helps users maintain power during outages and supports stable operation for different electrical equipment. The inverter provides a 5000VA capacity and delivers stable AC power output for compatible devices. Additionally, it supports backup power needs for appliances, computers, and other important electronics. The PROLINK IPS5003 features pure sine wave output to provide clean power for sensitive equipment. Moreover, this technology helps improve compatibility with devices that require stable electricity performance. The inverter includes an LCD display that allows users to monitor important system information. Furthermore, users can check battery status, input voltage, output voltage, and operating conditions easily. The PROLINK IPS5003 includes protection features against overload, short circuit, over-temperature, and low battery conditions. Therefore, it helps protect connected devices and improves system safety during operation. The inverter supports different backup power applications for homes and small offices. In addition, its practical design makes it suitable for users who need dependable energy support during power interruptions. The PROLINK IPS5003 Inverter combines high power capacity, pure sine wave technology, monitoring features, and protection functions. As a result, it provides a reliable backup power solution for everyday electrical needs. manufacturer link Specifications: Capacity: 5000VA Output Waveform: Pure Sine Wave Display: LCD Display Protection: Overload, Short Circuit, Over Temperature, Low Battery Protection Application: Backup Power for Home and Office Equipment
Description : The Professional Series (1P/1P) – Tower is an advanced, affordable on-line double-conversion technology single-phase UPS system. Tower versions are available with 1000VA to 10000VA models and these offer high reliability for workstations, server and network equipment. The Professional Series is designed with automatic voltage regulation (AVR) to protect against power outages, disturbances and spikes. High voltage battery chargers and battery extension assembly is available for the long run time application. Key Features and Benefits 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. 02 Years Warranty manufacturer link
Specifications : Professional II Series (1P/1P) Tower is specifically designed for operation in poor power areas. They provides high power density with long backup time in compact size. It’s ideal for ATMs, banking and other business critical applications. – True double-conversion – Microprocessor control optimizes reliability – Output power factor 0.8 – Wide input voltage (110 V – 300 V) – Converter mode available – ECO mode for energy saving – Generator compatible – Smart SNMP works well with either USB or RS-232 together – Comprehensive display allows easy monitoring and access of UPS status – Input power factor correction manufacturer link
Specifications : GENERAL UPS Type : Tower Phase : Single phase with ground Rating (VA) : 2000 Nominal Power (W) : 1600 Standard Model Dimension (mm) : 397x 145 x 220 (D x W x H) Weight (kg) : 17 Long-run Model Dimension (mm) : 397 x 145 x 220 (D x W x H) Weight (kg) : 6.8 INPUT Connection Type : IEC 320-C14 Nominal Voltage : 200/208/220/230/240 VAC Voltage Range : 110-300 VAC (Load at 50%) 160-280 VAC (Load at 100%) Frequency Range : 45 ~ 70 Hz Power Factor : >= 0.99 OUTPUT Connection Type : 3 x Universal socket (PRO902WS) 2 x Universal socket (PRO902WL) Nominal Voltage : 200/208/220/230/240 VAC Voltage Regulation : ±1% Frequency Range (Synchronized Range) : 47 ~ 53 Hz or 57 ~ 63 Hz Frequency Range (Batt. Mode) : 50 Hz ± 0.25 Hz or 60 Hz ± 0.3 Hz Current Crest Ratio : 3:1 Harmonic Distortion ; ≤3% THD (Linear load) ≤6% THD (Non-linear load) ALARM & INDICATORS Battery Mode : Sounding every 4 seconds Low Battery : Sounding every second Overload : Sounding twice every second Fault : Continuously sounding LCD : Load level, Battery Level, AC mode, Battery mode, Bypass mode and Fault CONNECTIVITY, CONTROL & MONITORING Front panel : Status LED, Function keys, LCD display Communication : Smart RS232* USB : Port BATTERY Standard Model Type : 12V / 9Ah Numbers : 4 Typical Recharge Time : 4 hours recover to 90% capacity Long-run Model Type : Depending on the capacity of external batteries Number : 4/6/8 Charging Current (max) : 1A / 2A / 4A / 6A Adjustable REAR PANEL 1. AC Input 2. Input circuit breaker 3. USB Communication port 4. RS-232 communication port 5. Intelligent slot 6. External battery connection (Only available for L model) 7. Output receptacles
The PROLINK Enerhome PRO2000 Line Interactive UPS is designed to provide reliable backup power and voltage protection for computers, networking equipment, and home electronics. It helps keep connected devices running during short power interruptions and unstable power conditions. The UPS provides a 2KVA capacity and uses Automatic Voltage Regulation (AVR) technology. Additionally, it helps correct voltage fluctuations and provides stable power output to improve equipment protection. The PROLINK PRO2000 features a line interactive design that allows quick switching to battery mode during power failures. Moreover, it provides efficient backup support for essential devices while reducing power-related risks. The UPS includes protection features against overload, short circuit, surge, and low battery conditions. Furthermore, these safety functions help protect connected equipment during different operating situations. The PROLINK Enerhome PRO2000 is suitable for homes, offices, and small workspaces that need dependable power backup. Therefore, it provides a practical solution for protecting computers, routers, and other important electronic devices. The compact design makes the UPS easy to install in different environments. In addition, its reliable performance helps users maintain stable operation during unexpected power interruptions. The PROLINK Enerhome PRO2000 2KVA Line Interactive UPS combines backup power, AVR voltage regulation, and protection features. As a result, it provides a reliable power solution for everyday electronic equipment. Specifications: Capacity: 2000VA / 1200W Technology: Line Interactive with AVR Protection: Overload, Short Circuit, Surge, Low Battery Protection Input Voltage: 220VAC Output Voltage: 220VAC
In the realm of uninterruptible power supplies (UPS), the Fanshine FSUPS 2000VA 900W stands out as a dependable solution, offering a robust and efficient power backup for your electronic devices. Transitioning to its key features, the UPS Fanshine FSUPS 2000VA 900W excels in providing a substantial power capacity, ensuring that your critical electronics remain powered during unexpected outages. This UPS is designed to safeguard your equipment and data. Moreover, this power supply solution impresses with its compact design, making it suitable for various settings, from home offices to small businesses. The Fanshine FSUPS seamlessly integrates into your space without compromising on performance. In addition to its functionality, the FSUPS 2000VA 900W offers versatile connectivity options, including multiple outlets for various devices. This ensures a flexible and efficient setup, protecting a range of electronics from power fluctuations. Furthermore, Fanshine’s commitment to user-friendly design is evident in the FSUPS 2000VA 900W’s easy setup and clear indicators. This ensures that users can monitor the status of their power supply effortlessly. In conclusion, the Fanshine FSUPS 2000VA 900W redefines reliability in power backup solutions, combining substantial capacity, compact design, and user-friendly features. Elevate your protection against power interruptions effortlessly with the FSUPS 2000VA 900W – your trusted solution for uninterrupted power! Specifications Model : FSUPS2000VA Input Voltage : 145VAC~290VAC Output Voltage : 195VAC~255VAC Output Wave Form : PWM/DC Output Frequency : 50Hz Backup Time : 10 to 15 minutes Noise Level : <45dB Operating Temperature : 0-45 Celsius
The Beco Mini DC UPS 8800mAh delivers compact and reliable power backup for small DC devices. It offers emergency power without bulky hardware. This helps protect devices during brief outages or unstable power. Users enjoy continuous operation with confidence. Moreover, the Beco Mini DC UPS features an 8800mAh battery for extended backup time. It supports devices like routers, cameras, and small electronics. This ensures continuous functionality when mains power fails. Backup power stays dependable. In addition, the DC UPS supports automatic switching when power cuts occur. It detects outages instantly and activates backup power without delay. This keeps your devices running smoothly. Protection remains seamless and reliable. Furthermore, the Beco Mini DC UPS includes stable DC output for sensitive electronics. Power delivery stays steady even under load. This helps reduce risk of damage. Devices operate without sudden stops. Also, the UPS delivers a compact and portable design for easy placement anywhere. You can install it near devices without taking much space. This adds convenience for small homes and offices. In addition, the Beco Mini DC UPS 8800mAh supports multiple connection options for flexible use. It works with DC devices requiring uninterrupted power. Also, the compact and sturdy casing improves durability for daily use. The build feels reliable and long‑lasting. Users can trust the UPS for regular backup needs. Overall, the Beco Mini DC UPS 8800mAh delivers dependable backup power, seamless switching, and flexible use in a compact form. It is ideal for small DC devices needing continuous power and stable operation. Specifications: MINI DC UPS POE 8800mah, 17W Built-in Lithium Battery 2200mAh*4 5VDC USB output, 3*Sockets DC output Interface 5V/9V/12V Over charge, Over discharge, Overload, & Short circuit protection Microprocessor controller guaranties high reliability Multi-LED Status Indicator For: Routers, CCTVs, Modem, Wireless Phones, Monitors, PSP, and others
APC 800VA BX800LI 415W UPS (IEC Plug) APC 650VA BX650LI UPS
PROLINK 2KVA AUTO VOLTAGE REGULATOR W/LCD PVR2000D PROLiNK PVR Series is designed to automatically maintain a constant voltage level to protect sensitive electronics from brownouts, under voltages and over voltages. The PROLiNK PVR takes efficiency to a new level with its microprocessor controller tailored to allow extremely fast response for detecting and regulating voltage. Equipped with a time-delay function, the PVR is able to protect connected devices from power-back surges.
Features and performances x Outstanding efficiency and overload. x Perfect management and limitation of AC sources. x Power shaving of the consumption peaks. x Automatic allocation of the power available. x Active filtering of the load steps on the genset. x Automatic protection of the sources against overload. x Powerful multi-stage PFC charger. x Ultra-short transfer time (from 0 to 15ms max.). x Automatic and efficient stand-by. x Compatible with AC coupling. x Display, programming and data logging. x RS-232 communication for remote supervision. x iPS Dim. : 44.50x20x17.2( LxWxH cm ) , 17.50 x 7.87×6.8 ( LxWxH inch) x Carton box Dim.: 53.5×30.5×30.5 (LxWxH cm) , 21.65×11.8×12 (LxWxH inch) x Weight : 25Kg ( 55lbs ) Model iPS 3700-24 Inverter Nominal battery voltage 24V Input voltage range 19 – 34V Continuous power @ 25°C 2000W Power 30 min. @ 25°C 2800W Power 25 sec. @ 25°C 5.6kVA Maximum load Up to short-circuit Maximum asymmetric load Up to Continuous power Load detection (stand-by) 2 to 25 W Maximum efficiency 86 – 90% Consumption OFF/Stand-by/ON 3W / 9W / 70W Output voltage Sine wave 220Vac (+/- 2%) / 190-245Vac Dynamic behavior 5 ms (on load change 0 to 100%) Overload and short-circuit Automatic disconnection up to 10 times restart attempt Overheat protection Warning before shut – with automatic restart Battery charger 6 step adjustable : I-U-Uo-Equalize-Uo(low)-U(periodic) Charging current adjustable 0 – 45A Maximum input voltage 265Vac Input AC voltage range Adjustable threshold from 150 to 265Vac Battery control Absorption end By duration 2 / 0.25 – 10 h or by current – / 4 – 30A Absorption voltage** 28.8 / 19 – 34V Periodic absorption voltage** 19 – 34V Floating voltage** 27.2 / 19 – 34V Reduced floating voltage 19 – 34V Equalization** By number of cycles (1 – 100) or at set interval (52 weeks) Equalization end By duration 4 / 0.25 – 10 h or by current – / 4 – 30A Deep-discharge protection 21.6 / 19 – 34V Reduced floating time 0 – 32 days Periodic absorption time 0 – 10 hours General data iPS 3700-24 Auxiliary Output 2 independent Transistor short circuit protected outputs Auxiliary Input 2 Opto Coupler Programmable Input 10V Æ 60VDC Net Weight 25Kg ( 55lbs ) Weight with the cartoon box 26.2Kg (57.5lbs) 1 Year warranty
INVO Online INH300 Centralized server center, mainframe, network control center, computing center Full Specifications : 3KVA 2100 W Half -Load 120 -300VAC, Full -Load 165V -300VAC 45.5Hz ~ 54.5Hz 220/230/240V ± 3% Waveform True Sine wave Frequency 50/60Hz ± 0.5 Distortion <3%(linear Load); <5%(Non -linear Load) Crest Factor 3:1 Efficiency 85% Overload Capacity 110%-150%:Switch to Bypass after 1min; >150%:Shutdown afte r 200ms Short Circuit UPS output turn off and alarm RS232 ;SNMP (Optional) LCD & LED Utility, Inverter, Bypass, Battery, Load ,Battery Mode ,Frequency , UPS Fault Indicator Audible Alarm -Battery Discharge Utility Failure, Beep/4s;Battery Low, Beep/1s UPS Abnornmal Continuous Beep and Red Led On Noise <55db (1Meter) Temperature 0°C~40°C Humidity 10%~90% Optional 19 inch Rack -mount Dimension (W * D * H) mm 357 x 144 x 215 439x190x341 514X262X455 (Long Time Mode) 514x262x710 (Standard Model) Specifications: Specifications : INVO Online UPS High Frequency 3000 VA, LCD Display Inbuilt Battery 6 x 12V/7Ah AC Input 2. Bypass 3. AC Output 4. Battery 5. Fault 6. Screen 9. LCD 1. AC Input 2. Bypass 3. AC Output 4. Battery 5. Fault 6. Screen 9. LCD 1 year warranty Manufacturer Link
The Twist Line Interactive UPS 1500VA TWUP1500/LI provides backup power protection for computers, networking devices, and office equipment. It uses line interactive technology with automatic voltage regulation for stable output performance. Additionally, the built-in dual 12V/7Ah batteries support continued operation during power interruptions. Moreover, the UPS includes LED status indicators for clear power monitoring and system alerts. It also supports overload and short-circuit protection for safer daily operation. Therefore, it helps protect connected devices from voltage fluctuations and sudden outages. Furthermore, the compact tower design fits home and office environments easily. The system also supports cold start functionality and simulated sine wave output for common electronic devices. Additionally, the automatic battery charging system improves operational reliability. Specifications: 1500VA line interactive UPS technology Built-in 2x12V/7Ah rechargeable batteries LED indicators for power status monitoring Automatic voltage regulation for stable output Overload and short-circuit protection system
UPS HAWK 2000VA 2kva 1 year warranty
APC UPS Accessories SURT192RMXLBP2 APC Smart-UPS RT192V RM 15/20KVA SURT models Battery Pack 2 Rows
Powerology Portable Power Generator,140400mAh Powerology 140400mAh Power Generator 500W Pure Sine-Wave Output -45W USB-C Power Delivery -18W USB-A Quick Charge -3.1A Dual USB Optimal Charge -220V UK AC Output -750W Max Surge
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
The APC UPS 600W 1000VA Line Interactive BV1000I-GR provides reliable backup power for home and office devices. First, it delivers line-interactive output to protect equipment from voltage fluctuations. In addition, it safeguards connected devices against surges, spikes, and short outages. Moreover, the compact design allows easy placement on desks or near electronics. Finally, the UPS includes LED indicators to monitor battery and load status. The BV1000I-GR ensures uninterrupted operation and protects important electronics during power interruptions. Specifications: 600W / 1000VA line-interactive output protects devices Safeguards against power surges, spikes, and outages Compact design for easy placement on desks or near electronics LED indicators monitor battery and load status Ensures uninterrupted operation during short power interruptions
General Topology Online double conversion Configuration Tower Part Number 9E3000I Rating (VA/Watts) 3000/2400 Dimensions (H x W x D, mm) 399 x 330 x 190 Weight (kg) 24.2 Warranty 2 years Electrical Input Connection (1) IEC-320-C20 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 (6) IEC-320-C13 (1) IEC-320-C19 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)
PCE CASA 1KVA inverter is a compact off-grid power solution designed for home and small office backup use. It helps keep essential devices running during power cuts, such as routers, lights, and small electronics. In addition, it provides pure sine wave output. Therefore, it delivers clean and stable power for sensitive devices. Moreover, it supports AC mains and generator input, which makes it flexible in different power conditions. Furthermore, PCE CASA 1KVA inverter includes smart battery charging control. As a result, it improves charging efficiency and helps extend battery life. It also supports automatic restart after power recovery, ensuring continuous operation. In addition, it includes built-in protection features. Therefore, it helps protect against overload, short circuit, and overheating. Moreover, it supports a cold start function for direct battery operation when no grid power is available. Overall, PCE CASA 1KVA inverter delivers reliable backup performance, stable output, and essential protection for everyday home and office energy needs. Specifications: 1KVA capacity for home and small office loads Pure sine wave output for stable device operation AC mains and generator input support Smart battery charging control for efficiency Built-in protection against overload and short circuit
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
APC Easy UPS SRV, 1600 Watts / 2 KVA, Online double conversion, Sine wave, 230V, Multi-function LCD status and control console, Surge Protection and Filtering, Generator compatible, Management Software, USB, 2 years warranty Electronics and Battery
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