Santak UPS uninterruptible power supply reminds you to take precautions against lightning strikes.
1. Santak UPS power supplies are installed upstream of critical equipment. Therefore , when lightning strikes a low-voltage power line or induces lightning on the cable, the overcurrent and overvoltage on the power conductors pass through the power distribution system and first impact the UPS. The UPS’s voltage regulation range is generally between 160 / 260V for single- phase and 320/ 460V for three-phase . It is impossible to prevent the overvoltage amplitude of a momentary lightning surge of 10-20kV. Therefore, when lightning strikes, it is the first to be impacted by the lightning current.
How can we reduce the occurrence of deep battery discharge in practice? The method is simple: When the UPS power supply is interrupted by a mains power outage and the inverter is powered by the battery, most UPS power supplies will emit a periodic alarm sound approximately every 4 seconds to notify the user that the power is now supplied by the battery. When the alarm sound becomes more rapid, it indicates that the power supply is in a deep discharge state, and emergency measures should be taken immediately to shut down the UPS power supply. Unless absolutely necessary, the UPS power supply should not be allowed to operate until it automatically shuts down due to low battery voltage.
The installation location of Santak UPS power supplies is crucial. According to the building zoning method of the International Electrotechnical Commission (IEC) 1312-1 (Protection against Lightning Electromagnetic Pulse), the UPS power supply room belongs to Zone 1 (LPZ1). Objects within this zone are unlikely to be directly struck by lightning, and the electromagnetic field may be attenuated. Therefore, the UPS power supply should be installed within Zone 1. Furthermore, to protect against the strong electromagnetic field generated by lightning current, the UPS power supply should be placed at a certain distance from the wall, with a distance of ≥ 0.83m from the down conductor of the external wall column reinforcement. This ensures the equipment is within a safe zone of the lightning current magnetic field. The machine casing should be shielded and grounded, and the cabinet should be reinforced with wires to ground, placing the area inside the cabinet in Zone 2 (LPZ2).
- UPS systems with internal surge protection devices come in two types:
- UPS systems equipped with substandard surge protection devices. These are products where manufacturers, in an effort to save costs, simply install a small-power metal oxide zinc varistor (MOV), which only provides some protection against very small induced lightning strikes.
- Some imported UPS systems and those manufactured by well-known domestic UPS manufacturers are equipped with standard surge protectors according to the international standard IEC801-5 (which suppresses and absorbs strong surges in lightning voltage and current at the input of the power supply line, with an impulse current of 20kA, an impulse voltage of 6kV, and a waveform of 8/20us). However, whether these UPS systems can effectively protect themselves and other downstream power supplies and equipment from lightning damage remains to be seen. Long-term monitoring data shows that direct lightning strikes can generate overvoltage amplitudes as high as 100kV on ordinary low-voltage overhead lines and 40-60kV on telecommunication lines. Induced lightning overvoltage amplitudes can reach up to 20kV on unshielded overhead lines and up to 10kV on unshielded underground cables. Therefore, even UPS systems equipped with standard surge protectors can still be damaged by lightning strikes if effective high-energy surge protectors are not installed at the upstream of the power supply line (distribution room, cabinet, and box).
Connecting a Santak UPS power supply to a grounded AC input power source requires an appropriate branch circuit breaker; connecting it to any other type of outlet could result in electric shock.