Ex-proof junction box for CNG dispenser

 Electrical performance of the sub-box
(1) Insulation resistance
1 Under the standard atmospheric conditions of the test, the insulation resistance between any two ends and between any end and the metal box shall not be less than 5 × 104MΩ.
2 After the condition test, the insulation resistance between any two ends and between any end and the metal box body should not be less than 5 × 103MΩ.
(2) Contact resistance of the sub-box
1 Under the standard atmospheric conditions of the test, the contact resistance between the wire and the terminal should not be greater than 5 × 10-3 Ω.
2 After the condition test, the increase in the contact resistance between the wire and the terminal should not be greater than 3 × 10-3 Ω.
(3) Electricity resistance
1 Under the standard atmospheric conditions of the test, when any two terminals and any one terminal and the metal box body are subjected to the AC effective value of 500V, 1 min should have no breakdown and arc phenomenon.
2 After the condition test, when the AC effective value is 500V between any two terminals and between any one terminal and the metal box body, the 30s should have no breakdown and arc phenomenon.