What is the maximum approved static ground electrostatic voltage (with low current)?

What is the maximum approved static ground electrostatic voltage (with low current)?

• A. 5,000 volts
• B. 100,000 volts
• C. 50,000 volts (with low current)
• D. 10,000 volts

Answer: (C)

Static charges can build up on an aircraft even when only a tiny current would flow. When the system is grounded and current is kept very low, the limiting factor is the insulation and the gaps through which a discharge could occur. The approved maximum static ground voltage under these low-current conditions is about fifty thousand volts, because beyond that the risk of arcing or breakdown increases and could damage insulation or components. So fifty thousand volts is the safe upper limit for low-current static grounding. Values much lower would unnecessarily constrain operations, while higher values would exceed what the grounding and insulation can safely tolerate.

Static charges can build up on an aircraft even when only a tiny current would flow. When the system is grounded and current is kept very low, the limiting factor is the insulation and the gaps through which a discharge could occur. The approved maximum static ground voltage under these low-current conditions is about fifty thousand volts, because beyond that the risk of arcing or breakdown increases and could damage insulation or components. So fifty thousand volts is the safe upper limit for low-current static grounding. Values much lower would unnecessarily constrain operations, while higher values would exceed what the grounding and insulation can safely tolerate.