Installation and design requirements of large UPS power supply

1. Requirements for large-scale UPS power supply on site and environment

(1) The equipment installation site should be an “industrial type” hard cement-type horizontal floor. If an anti-static raised floor is used, it needs to be designed according to the weight of the UPS on the basis of considering the average load of the floor. Make steel brackets for mounting equipment.

For most large-scale UPS, the cables of the standard model are bottom-in and bottom-out type. The ventilation air inlet of the UPS cabinet is located on the front or side of the cabinet, and the air outlet is on the upper or rear of the cabinet. For this reason, before installing the UPS, we need to check whether the user site meets the installation conditions. If the user uses bridge cable laying, the cable should be selected as the top-in and top-out model, and it is not allowed to go to the site and re-drill holes from the cabinet box. , in this case, it will cause hidden dangers to the UPS equipment.

(2) The UPS power supply system should be installed in an operating environment with sufficient ventilation, coolness, low humidity and clean air with dust-free conditions. Although the temperature range allowed by the general UPS is between 0°C and 40°C. However, if conditions permit, the ambient temperature should be controlled below 35°C. In addition, flammable, explosive or corrosive gas or liquid items should not be stored in the room where the UPS is operating.

(3) It is strictly forbidden to install the UPS in a dusty working environment with metal conductivity, otherwise it will cause a short circuit failure of the equipment. It is also not advisable to place the UPS near a heat source.

(4) Regardless of whether the UPS battery pack is equipped with a charger with temperature compensation. In order to ensure the service life of the battery pack, the temperature of the battery room should be controlled between 20°C and 25°C.

(5) According to the shape of the UPS, there must be space for maintenance when placing the UPS. Some manufacturers of UPS generally require a space of 40CM-50CM on the left and right sides, and at least 50CM in the back. If it is a low-power model with casters, the space can be appropriately reduced, but the cooling and ventilation of the UPS must be ensured.

(6) Note: Although we require the ambient temperature of the UPS room to be as low as possible, we cannot install the UPS or battery directly below the air conditioner.

(7) In order to ensure the reliable operation of the UPS and battery packs, it is strictly forbidden to place sundries on the top cover of the UPS and battery pack cabinets.

2. Basic installation design parameters that users should consider when purchasing UPS

Due to the user’s load and the power factor of the UPS, the UPS selected by the general customer basically has a certain margin of power. We should determine the power supply of the computer room and the required power according to the power of the UPS and the battery pack. Cable diameter, since the UPS and battery pack are generally installed indoors, the AC input end of the UPS will be close to the user’s switchboard. If the user’s mains power reaching the computer room is much larger than the UPS’s power, our UPS input cable diameter can be According to the general short-distance cable configuration, the cable of the short-distance copper core wire can generally withstand a current of 4.5A per square section. When configuring the cable, we also need to add the actual power used and the power of the battery floating charge to configure the appropriate cable. If the input power of the user’s switchboard cannot meet the power supply requirements of the UPS, in order to ensure the normal use of the UPS system, we must require the customer to provide a power environment that meets the equipment use.

It is understood that the connection between the UPS and the battery is generally completed by the UPS supplier. We must determine the connection line of the battery pack according to the power of the UPS and the configuration backup time of the UPS. A reasonable configuration can Ensure the reliability of the power supply system of the UPS. Generally, the discharge current of the battery prohibits long-term discharge at a discharge rate of more than 3C. Therefore, when we configure the battery, we should configure the battery reasonably according to the maximum discharge current of the battery pack in the UPS system.

For different types of UPS, the requirements for power supply cables are also different. For example, for a UPS of a certain brand and series A, since its bypass power supply is connected to phase C of the mains, we install the phase C input line of the UPS during installation. The diameter is generally required to be thicker than the diameter of the input phase A and B. At the same time, due to the problem of the current power grid environment, in the input wiring mode of the three-phase five-wire system, except that the grounding wire diameter can be slightly thinner, the neutral wire must be at least It should also be the same diameter as the phase wire, and it needs to be thickened if necessary. For a UPS of a certain series B of a company, because the machine has three inputs and three outputs, the general input wire diameter can be the same except for the ground wire that is slightly thinner. The output wire diameter can be adjusted appropriately according to the actual load. Except for the UPS with three inputs and one output, the output wire diameter of the UPS is generally smaller than the input wire diameter.

If there is a generator at the user’s place, the power and performance of the generator must meet the requirements of the UPS. Generally, the power of the generator is more than 4-5 times the power of the UPS. The quality of the generator is not good. Because the internal resistance of the generator is much greater than that of the mains, for the phase-controlled rectifier UPS, it may appear that the generator works abnormally when supplying power, resulting in oscillation.

Mylion UPS link: https://myliontech.com/category/other-products/ups/