Common hidden dangers of diesel generators and their basis

1. The diesel generator casing is not grounded

Based on: GB50303-2015 Construction Quality Acceptance Code for Electrical Engineering

Article 7.1.6-The exposed conductive parts of the generator body and mechanical parts should be reliably connected to the protective conductor respectively and should be marked.

2. The oil storage tank does not meet the 3-hour operation requirement

Based on: XF503-2004 Technical Regulations for Inspection of Building Fire Protection Facilities

Article 4.2.2.2.1-The oil storage tank should be able to meet the generator operation for 3~8h, and the oil level display should be normal.

3. The battery pack for starting the diesel generator has not taken measures to prevent oil and water from entering.

Based on: GB51348-2019 Civil Building Electrical Design Standard

Article 6.1.8-The self-starting and parallel operation of the generator set shall comply with the following provisions:

6 The self-starting of the self-contained diesel generator set should adopt the electric starting method, and the electric starting equipment should be set according to the following requirements:

1) The voltage of the battery pack for electric starting should be 12V or 24V, and the capacity should be determined based on the continuous start of the diesel engine for no less than 6 times; 2) The battery pack should be set close to the starting generator set and should be prevented from oil and water from entering;

4. The instruments and buttons of the diesel generator sets are damaged

Based on: XF503-2004 Technical Regulations for Inspection of Building Fire Protection Facilities

Article 4.2.2.1.1-Instruments, indicator lights and switch buttons should be intact and the display should be normal.

5. The diesel generator set does not use the 24V battery electric ignition start method

Based on: HG/T 20664-1999 Technical Regulations for Power Supply Design of Chemical Enterprises

Article 5.5.5-Diesel generator sets should use 24V battery electric ignition start method.

6. The emergency operation time of the diesel generator set is less than 1 hour

Based on: HG/T 20664-1999 Technical Regulations for Power Supply Design of Chemical Enterprises

Article 5.5.3-The emergency operation time of the diesel generator set is determined according to the minimum power supply time required by the load with special power supply requirements, and shall not be less than 1 hour.

7. The exhaust pipe of the diesel generator is not equipped with a heat insulation protective layer

Based on: GB51348-2019 Civil Building Electrical Design Standard

Article 6.1.4-The unit should be installed in a dedicated machine room, and the layout of the machine room equipment should comply with the following provisions:

6 The installation of exhaust pipes of the unit shall meet the following requirements:

1) The exhaust pipe of each diesel engine shall be led to the exhaust duct separately, and it is advisable to install it overhead or in the trench; the exhaust pipe elbows should not be too many and can be freely displaced; the horizontal exhaust pipe should have a slope of 0.3%~0.5% to the exhaust duct, and a drain valve should be installed at the lowest point of the exhaust pipe;

2) When the indoor part of the exhaust pipe is installed overhead, a heat insulation protective layer should be installed;

3) The exhaust resistance of the unit should not exceed the diesel engine exhaust pipe. The back pressure requirement of the oil engine, when the exhaust pipe is long, a natural compensation section should be used and the diameter of the exhaust pipe should be increased; when there is no condition to set a natural compensation section, a compensator should be installed;

4) An elastic bellows should be installed at the connection between the exhaust pipe and the diesel engine exhaust port;

5) A protective cover should be added to the exhaust pipe passing through the wall, and a rain cap should be installed at the outlet when it exits the roof;

6) Non-supercharged diesel engines should be equipped with a muffler on the exhaust pipe; two diesel engines should not share a muffler, and the muffler should be fixed separately.

8. The diesel generator set used as an emergency power supply is not equipped with a fast automatic starting device and a power switching device. When the working power supply is normal, the diesel generator set is not in a ready-to-start state.

Based on: HG/T 20664-1999 Technical Regulations for Power Supply Design of Chemical Enterprises

Article 5.5.1 - Diesel gensets used as emergency power supplies must be equipped with a fast automatic starting device and a power switching device. When the working power supply is normal, the diesel generator set is in a ready-to-start state. When the working power supply is interrupted, the diesel generator set should be started quickly and immediately to supply power to the loads with special power supply requirements. After the working power supply is restored, it will automatically switch to the working power supply after a delay, and the diesel generator set will automatically stop.