Elevator five-way intercom three-way intercom system NBT NKT wired and wireless machine room car intercom emergency power supply

Five-way intercom standard configuration; 2 main units (duty room and computer room), 1 built-in auxiliary unit (control box)
2 external auxiliary machines (car roof and pit), 1 alarm bell, 1 emergency light,
1 emergency power supply
Three-way intercom standard configuration: 2 hosts (duty room and computer room), 1 built-in auxiliary machine (control box)
1 alarm bell, 1 emergency light, 1 emergency power supply
Free configuration: can be freely configured according to customer needs

When the emergency light cannot be on
1.Check whether the bulb of the emergency light is available?

2Whether the polarity is reverse?
The export cannot be short for long time