Narrative:

In our routine overnight hangar we are repeatedly being electrically shocked by the aircraft while performing nightly maintenance. This has only been an issue this year. This has been repeatedly brought to management's attention and we have been told that licensed electricians have been brought in when available at their convenience to look at the problem and [that] there is none. What is happening when the aircraft comes to the hangar for nightly maintenance. We need to hook-up a ground power [electrical] cart to supply electrical power to the aircraft. The ground power cart is hooked-up to the electrical drop located at the north end on the hangar. It is a dual hook-up cart (can supply power to two aircraft at one time). We were told that the reason we are getting shocked is because the aircraft is not grounded to the hangar floor. When an aircraft is grounded; it is to make the aircraft and what it is grounded to; electrically the same. I was personally getting shocked when hooking up the aircraft to ground. I took out my volt meter and found we are passing alternating current (AC) volts and amps from the aircraft to the hangar floor ground [connection]. This should not happen. The power cart should be supplying the electrical ground back to the power source. This is dangerous because somewhere we are not providing a way for the power cart to return all the voltage back to the power source ground and it is building up on the aircraft. [The] poor hangar wiring has been brought to management numerous times as stated and we have been told that licensed electrical technicians have been into check out the hangar and power cart and are not able to find any significant findings. We have also been told that the licensed electrical technician believes that it is because it has been so dry and the dirt around the building grounding rod is dry; not allowing all the power to return to ground. Obviously it is still a problem even after the electricians have checked out the power source. It is a dangerous situation every night. It does not happen every night. The wiring needs to be thoroughly gone over. It is getting to the point that we do not want to work on the aircraft because we are getting shocked.

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Original NASA ASRS Text

Title: An Aircraft Maintenance Technician (AMT) reports about the reluctance of their Maintenance Management to address the numerous incidents of electrical shocks mechanics were experiencing after connecting a portable ground power cart to their ERJ-170 aircraft; including aircraft with open fuel tanks.

Narrative: In our Routine Overnight Hangar we are repeatedly being electrically shocked by the aircraft while performing nightly maintenance. This has only been an issue this year. This has been repeatedly brought to Management's attention and we have been told that licensed electricians have been brought in when available at their convenience to look at the problem and [that] there is none. What is happening when the aircraft comes to the hangar for nightly maintenance. We need to hook-up a ground power [electrical] cart to supply electrical power to the aircraft. The ground power cart is hooked-up to the electrical drop located at the north end on the hangar. It is a dual hook-up cart (can supply power to two aircraft at one time). We were told that the reason we are getting shocked is because the aircraft is not grounded to the hangar floor. When an aircraft is grounded; it is to make the aircraft and what it is grounded to; electrically the same. I was personally getting shocked when hooking up the aircraft to ground. I took out my Volt Meter and found we are passing Alternating Current (AC) volts and amps from the aircraft to the hangar floor ground [connection]. This should not happen. The power cart should be supplying the electrical ground back to the power source. This is dangerous because somewhere we are not providing a way for the power cart to return all the voltage back to the power source ground and it is building up on the aircraft. [The] poor hangar wiring has been brought to Management numerous times as stated and we have been told that licensed electrical technicians have been into check out the hangar and power cart and are not able to find any significant findings. We have also been told that the licensed electrical technician believes that it is because it has been so dry and the dirt around the building grounding rod is dry; not allowing all the power to return to ground. Obviously it is still a problem even after the electricians have checked out the power source. It is a dangerous situation every night. It does not happen every night. The wiring needs to be thoroughly gone over. It is getting to the point that we do not want to work on the aircraft because we are getting shocked.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.