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Chapter 3 Electrical Assemble
4. Earthing Method
The UPS rectifier source has no neutral cable. The bypass and output source have neutral cables and the input and output neutral cables are short circuited.
The lightning protection earth PE and the protection earth of the cabinet are connected as shown in Figure
PE for lightning protection
PE inside cabinet
Protective earth
Fig. 3-5 Wiring inside cabinet
Generally, the separated neutral mode is better for human safety. The united connection mode is better for the UPS system. If there is
In the bottom cable entry mode, the protection earth cable should be connected with a copper terminal on the beam inside the cabinet or connected to the copper busbar marked with PE. User board M8x12 to fix the cable.
Note
The leakage current of the UPS should be less than 1 ampere.
The earthing resistance of the UPS cabinet should be less than 1 ohm.
3.2.2 Signal cable
The Signal cable includes serial communication cables, control cables of input/output contacts, logic and load sharing cables.
1. Routing the signal cable
The signal cables should be routed according to Figure
28