What Needs to Be Paid Attention to During UPS Installation? Today, I will introduce to you in detail the 12 issues that need attention during UPS installation.
I. Power Distribution Requirements:
For the input and output wiring of the equipment, the user’s electrician should connect them beforehand and pull them to the machine placement site with a certain length reserved (usually 1-1.5m long) to facilitate smooth installation after the machine arrives. For those requiring factory personnel to install, the user should prepare everything (including the arrival of municipal power and the readiness of the load) before the factory can send personnel.
II. Selection of Incoming and Outgoing Wire Diameters:
The selection of the wire diameters for the input and output of the machine must not be lower than the national electrical safety standards. Special attention: For three-phase input and single-phase output machines, the incoming wire diameters for the bypass live wire and neutral wire must be 3 times those of the other two-phase live wires! Wire type/maximum current carrying capacity reference:
(1) 2.5mm²: 2.5×8A;
(2) 6mm²: 6×7A;
(3) 10mm²: 10×6A;
(4) 16mm²: 16×5A;
(5) 25mm²: 25×5A;
(6) 35mm²: 35×4A;
(7) 55mm²: 55×4A;
(8) 75mm²: 75×3A.
III. Wiring Essentials:
It is best to choose multi-core flexible wires for all input and output copper wires for easy user wiring and machine wiring. The underground wiring for the input and output of the machine should have a metal sheath (especially for wiring under the antistatic floor of the machine room) to prevent damage from rat bites, accidental breaks, and burns. The metal sheath can also shield electromagnetic interference, which is beneficial for the underground wiring of communication equipment signal lines.
IV. Output Precautions:
When wiring, the output of the machine must be pulled separately! The dedicated outlet strips/sockets set up for the output must be strictly distinguished from daily electrical outlet strips/sockets and marked with prominent signs. The output outlet strips/sockets of the machine should not be placed alongside or stacked with ordinary outlet strips/sockets to prevent accidentally plugging in power tools such as electric drills or vacuum cleaners, which may damage the power supply. UPS is a precision power supply, more suitable for weak inductive loads such as computers. Do not plug in too many receipt printers! Strong inductive loads such as pressure machines, copiers, laser printers, and electric rolling shutters in banking systems cannot be plugged in! If used, the power matching ratio between the UPS and such strong inductive loads or production equipment such as SMT machines, as well as medical equipment such as CT machines and MRI, must be at least 4:1. Similarly, the power matching ratio between conventional EPS and power equipment is above 5:1.
V. Safety Grounding:
Check the grounding wire to ensure its grounding resistance complies with national standards, which is beneficial for the safe operation of the machine and lightning protection. An input air switch or circuit breaker (the neutral wire should not be set separately) should be installed in the power distribution box/cabinet at the input front end of the machine for periodic discharge testing of the UPS/EPS battery, but its model should not be too small and should be slightly larger than the maximum input current of the UPS to avoid frequent tripping due to its low power rating. No leakage protection switches should be connected at the input front end of UPS and EPS.
VI. Balanced Power Consumption:
The power distribution of three-phase power consumption in the user’s power distribution box/cabinet should be balanced as much as possible. Large differences in distribution can cause excessive neutral line (neutral) current and high neutral-to-earth voltage, which may lead to unsafe machine operation or even cause fires.
VII. Operating Environment:
UPS and EPS should not be placed in damp, dirty, or airless environments; small UPS units should not be directly stacked on the ground, and padding should be placed underneath to prevent internal condensation during spring! Medium and large machines are best placed in a dedicated machine room. A good operating environment (such as low dust, appropriate ambient temperature and humidity) can greatly extend the lifespan of the machine and the user’s various loads. Above 25°C, the battery’s lifespan is halved for every 10°C increase. Above 30°C, the machine’s lifespan is halved for every 10°C increase.
VIII. Ventilation/Load-bearing Safety:
The machine should be placed so that the inlet and outlet air ducts are no less than 30 cm away from the wall for better heat dissipation! For medium and large UPS models with long backup times, the batteries provided also need to consider the load-bearing pressure of the floor (international standard: no more than 1,000 kg per square meter for office buildings and no more than 1,400 kg for industrial buildings). If the standard is exceeded, it needs to be resolved by increasing the load-bearing area to reduce the pressure, usually by setting up a large steel plate or increasing the number of battery cabinets.
IX. Lightning Protection Needs:
For UPS and EPS users in suburban and open areas, due to the lack of high-rise buildings and the reliance on overhead lines for power transmission, overhead lines are prone to lightning strikes during thunderstorms. Users should install a dedicated high-power lightning protector at the input front end of the machine to effectively prevent lightning from damaging the equipment and user loads.
X. Initial Inspection Before Installation:
Before installing medium and large machines, open the machine door and check whether there are any loose or falling phenomena in the circuit boards, cables, DC capacitors, fuse tubes, screws, wires, mechanical parts, transformers, etc., inside the machine.
(1) The above process is to prevent adverse phenomena caused by significant vibrations during transportation.
(2) When inspecting the above process, if the lighting is insufficient, use a flashlight or other light source to carefully inspect before proceeding to the next step.
XI. Phase Sequence Requirements:
Three-phase UPS machines have phase sequence requirements for input wiring (EPS has no requirements). Connect the municipal power U, V, W, N to the UPS according to the phase sequence, then connect the grounding wire and shake it by hand to check if the wires are loose and tighten them. After confirming the R, S, T phase sequence, use a multimeter to measure the voltage between U-N, V-N, and W-N within the range of 220V ± 25%, with a frequency of 50Hz ± 1. Turn on the machine’s municipal power input switch, then turn on the machine’s automatic bypass switch. If there is a long alarm sound, it means the municipal power input phase is wrong, and the phase should be corrected immediately (swap any two of the three input phases, and no long alarm sound indicates the correct phase).
XII. Battery Pack Connection:
After connecting the battery pack, connect the positive and negative wires of the battery pack to the positive and negative terminals of the machine, ensuring that the positive and negative connections of the battery pack are consistent with the positive and negative terminals of the machine (i.e., positive to positive, negative to negative) and tighten them. Measure the terminal voltage of the battery pack, which should be approximately: number of batteries × 13.5V. For a running machine with the battery pack disconnected, the measured open-circuit charging voltage should be: number of batteries in the same pack × (13.6-13.8V).
