UPS ONLINE 2KVA 1600W PURE SINEWAVE 1 YEAR WARRANTY
Presentation High quality, Double-conversion On-line UPS designed for essential power protection needs even in the most unstable power conditions. Lead time Usually in Stock General provided equipment Basic UPS signalling RS-232 cable CD with software Rack mounting brackets User manual USB cable Number of tare power 25 W Number of power module free slots 0 Number of power module filled slots 0 redundant No UPS size WS Physical number of rack unit 5U colour Black depth 61.5 cm height 21.95 cm net weight 78 kg USB compatible Yes width 43.8 cm Input network frequency 40…70 Hz number of input connectors 1 hard wire 3-wire (1P + N + E) input voltage limits 110…300 V adjustable (half load) 176…300 V inputvolt_other 220 V 240 V input voltage 230 V Output rated power in W 6000 W Maximum configurable power in W 6000 W output frequency 50/60 Hz +/- 3 Hz sync to mains outputvolt_other 220 V 240 V crest factor 3 : 1 UPS type Double conversion online Wave type Sine wave output connector type Hard wire 3-wire (H N + E) 1 bypass type Internal bypass (automatic and manual) curve equation Efficiency curve load maximum 100 % curve X-axis maximum 100 % curve X-axis minimum 0 % curve X-axis title Load curve X-axis units Percentage curve Y-axis maximum 100 % curve Y-axis minimum 50 % curve Y-axis title Efficiency curve Y-axis units Percentage efficiency 94 % (full load) graph display 1 half load runtime 00:10:00 3000 W output voltage 230 V Maximum configurable power in VA 6000 VA rated power in VA 6000 VA Conformance product certifications CE standards IEC 62040-1-1 IEC 62040-1-2 Environmental ambient air temperature for operation 0…40 °C relative humidity 0…95 % non-condensing operating altitude 0…3000 m ambient air temperature for storage -15…60 °C Storage Relative Humidity Non-condensing 0…95 % storage altitude 0…15000 m acoustic level 55 dB show note OP temperature No IP degree of protection IP20 Batteries & Runtime battery type Lead-acid battery number of battery filled slots 0 number of battery free slots 0 Battery recharge time 3 h additional information Configurable for 220 : 230 or 240 nominal output voltage liquid value 0 battery curve D Battery power in VAH 1512 VAh runtime battery option SRV240RLBP-9A 1 3024 VAh SRV240RLBP-9A 2 4536 VAh SRV240RLBP-9A 3 6048 VAh SRV240RLBP-9A 4 7560 VAh SRV240RLBP-9A Communications & Management free slots 1 control panel Multifunction LCD status and control console alarm Alarm when on battery : distinctive low battery alarm : overload continuous tone alarm Emergency power off Yes manufacturer link 1 YEAR WARRANTY
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
UPS PCE EXDC-2 MAX UPS Adapter for Cameras & Modems
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
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
APC UPS Accessories SURT192RMXLBP2 APC Smart-UPS RT192V RM 15/20KVA SURT models Battery Pack 2 Rows
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
APC 800VA BX800LI 415W UPS (IEC Plug) APC 650VA BX650LI UPS
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
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
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
【2021 New 60W PD Version】This well-rececived large power bank is now back with 2 high-speed USB-C PD ports to refresh your portable charging experience. USB-C (1) port can transfer up to 60W power to your laptop while USB-C (2) port can keep your phones charged at a maximum speed of Max. 27W on the go. 【Massive Capacity】Packed with a enormous capacity of 72000mAh/266Wh as well as battery management system, this portable charger can pump out enough power to multiple devices simultaneously and securely at a high power conversion rate up to 90%. (Note: not TSA-approved, not allowed on a plane) 【Off-Grid Power for CPAP】The high-performing DC 12V/5A (150W max.) cigarette lighter port is ready to boost most CPAP machines on the market with a CPAP adapter (PURCHASED SEPARATELY), including Philips Dreamstation, Resmed Airsense/Aircurve 10, and Resmed S9. Please turn OFF the heater & the humidifier for extended runtime. 【Faster Recharging】Recharge the battery pack at full-speed via a solar panel with the two-way DC port in 3-4 hours, and the two-way USB-C (1) port in 5-6 hours. Please note that the USB-C (1) port and the DC port CANNOT be used at the same time. 【10W Wireless Charging】Align your smartphone to the charging pad to get rid of cords jumbled in your bag. The smart indicator allows you to keep taps on real-time charging status effortlessly. DOES NOT support wireless earbuds, smartwatches, and other low-power devices. https://www.renogy.com/content/files/Manuals/RC-P72000-01%202018.3.23.pdf
The Yuasa SWL2500T Industrial VRLA Battery delivers reliable power for industrial and backup applications. First, it provides consistent energy output for critical equipment and systems. In addition, the valve-regulated lead-acid (VRLA) technology ensures maintenance-free operation and extended service life. Moreover, the battery features durable construction, vibration resistance, and high discharge efficiency for demanding environments. The compact design allows easy installation in various setups. Finally, its dependable performance, safety features, and long-term reliability make it ideal for industrial, UPS, and emergency power systems. Specifications: VRLA Technology: Maintenance-free operation with long service life High Discharge Efficiency: Reliable power for critical equipment Durable Construction: Resistant to vibration and harsh environments Compact Design: Easy installation in various industrial setups Industrial Reliability: Ideal for UPS, backup, and emergency power
Aokly Gel Battery 12V – 200A 58.5Kg manufacturer link
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
The PCE PCD 12V 100Ah Deep Cycle Battery delivers strong and reliable power for many applications. It offers a larger 100Ah capacity for extended use. This helps engines, systems, and devices run longer between charges. Users experience dependable energy when needed most. Moreover, the PCE PCD Deep Cycle Battery uses a deep cycle design built for repeated discharge and recharge. It supports long-term use without damage. This increases the battery’s lifespan and reduces replacements. Performance remains consistent over time. In addition, the battery provides a stable 12 V output for balanced power delivery. It suits solar systems, RVs, marine setups, and backup power solutions. Power stays steady for lights and appliances. Daily use becomes more efficient. Furthermore, the PCE PCD 12V 100Ah Deep Cycle Battery features a rugged casing that protects internal cells. The strong build resists wear and harsh conditions. This helps maintain performance in many environments. Durability feels reassuring. Also, the battery supports deep discharge recovery for long service life. It recovers well after heavy use cycles. This improves energy storage and reliability. Users rely on strong power anytime. In addition, the PCE PCD Deep Cycle Battery is easy to install in compatible racks and holders. Connections stay secure and simple. Setup feels user-friendly for both beginners and professionals. Installation remains smooth. Furthermore, the PCE PCD Deep Cycle Battery performs steadily across varying temperatures. It stays reliable in moderate heat and cold. This makes it ideal for outdoor and mobile use. Overall, the PCE PCD 12V 100Ah Deep Cycle Battery delivers dependable power, long life, and robust performance. It fits homes, boats, RVs, and solar systems. This battery is perfect for users who want strong, lasting deep cycle energy every day. Specifications: Voltage : 12V Capacity : 100Ah
UPS battery 12V 7A Battery for UPS 7A 12v
INVO Online INH600 INVO Online UPS High Frequency 6000 VA, LCD Display Inbuilt Battery 16 x 12V/7Ah online ups system high frequency and high load management. Full Specifications : AC Input Bypass AC Output Battery Fault Screen LCD AC Input Bypass AC Output Battery Fault Screen LCD 6 KVA/4200W Half -Load 120 -300VAC, Full -Load 165V -300VAC 176V`~276VAC Frequency 45.5Hz ~ 54.5Hz Power Factor 0.95 Output Voltage 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 Battery Model 12V Sealed Lead -Acid Voltage 36DC 96DC 240C Configuration Recharge 90% Capacity after 8 Hours charging 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 : AC Input Bypass AC Output Battery Fault Screen LCD AC Input Bypass AC Output Battery Fault Screen LCD 1 year warranty Manufacturer Link
UPS ONLINE 3KVA 2400W 1 YEAR WARRANTY ABSOLUTELY PURE SINUSWELLE – With this inverter / inverter you operate your 220V devices via a 24V battery and a continuous power of 2400W 3KVA. Inverter is a device that allows you to use electrical devices everywhere, even when you are not at the power source MULTIFUNCTION HYBRID UNIT – Thanks to the small LCD display, it is also possible to charge the batteries with AC / solar charge controllers, setting the input voltage range and charging current. MODERN PROTECTION FEATURES – The device has many modern safety features such as: overload protection, overheating protection, short-circuit protection, so it is also suitable for home appliances, as well as microwaves, air conditioners, refrigerator, fan and daylight lamp. HIGH QUALITY MATERIALS – Equipped with PWM control, the inverter generates a pleasing amount of waste heat.
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
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)
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
