Emergency diesel generators are mainly used in important places. In the event of an emergency or power outage, the generator sets quickly restore power and extend the power supply time by supplying power to the emergency load. Such load is classified as level ① load. For equipment, instruments, and computer systems with strict requirements on power outage time, in addition to having a generator set, batteries or UPS power supply should also be provided.
The working characteristics of emergency diesel generators are as follows:
The first characteristic is for emergency use, with a short continuous working time, generally only requiring continuous operation for a few hours (≤12H);
The second characteristic is as a backup, the emergency generator set is in a stopped waiting state normally. Only when the main power supply is completely out of service and all power sources fail, will the emergency diesel generator set start and supply power to the emergency load. When the main power supply returns to normal, it will immediately switch off and stop.
(1) Determination of generator capacity for emergency diesel generators
The rated capacity of the emergency diesel generator set is the 12-hour rated capacity after atmospheric correction. The capacity should be able to meet the total emergency load calculation and be verified according to the generator capacity to meet the requirements for the start-up of the largest single capacity motor in level ① load. Emergency generators are generally selected as three-phase AC synchronous generators, with a rated output voltage of 400V.
(2) Determination of the number of emergency diesel generator sets
When there are multiple generator sets for backup, generally only one emergency diesel generator set is set. From a reliability perspective, two generator sets can also be selected for parallel power supply. The number of emergency power supply generator sets generally should not exceed 3. When multiple generator sets are selected, the generator sets should be as much as possible of the same model, capacity, and similar voltage regulation and speed regulation characteristics, and the fuel properties should be consistent to facilitate maintenance and common spare parts. When there are 2 emergency power supply generator sets, the self-starting device should enable the two generator sets to be mutually backup, that is, after a delay confirmation of the power failure of the mains power supply, an emergency self-starting instruction is issued, and if the first generator set fails to self-start for 3 consecutive times, an alarm signal should be issued and the second diesel generator set should be automatically started.
(3) Selection of emergency diesel generators
Emergency generator sets should preferably use high-speed, high-pressure, low-fuel consumption diesel generators. High-speed, high-pressure diesel engines have a larger single-unit capacity and occupy less space; the diesel engine is equipped with electronic or hydraulic speed control devices, with better speed regulation performance; the generator should be selected with a brushless excitation or phase-recombiner device to be more reliable, with a lower failure rate, and easier maintenance and repair; when the capacity of the single air conditioner or motor in level ① load is large, emergency generators with third harmonic excitation should be selected; the generator should be installed on a common chassis with a shock absorber; the exhaust pipe outlet should be equipped with a muffler to reduce the noise impact on the surrounding environment.
(4) Control of emergency diesel generator sets
The control of emergency generator sets should have a rapid self-starting and automatic input device. When the main power supply fails and is disconnected, the emergency generator set should be able to quickly self-start and restore power supply. The allowable power outage time for level ① load is from tens of seconds to several tens of seconds, which should be determined according to specific circumstances. When the main power supply of an important project is disconnected, first, a determination time of 3-5 seconds should be set to avoid the instantaneous voltage drop and the time for the mains power grid to close or the automatic input of the backup power supply, and then an instruction to start the emergency generator set should be issued. From the issuance of the instruction, the generator set starts, speeds up to be able to supply full load, it takes a certain time. Generally, large and medium-sized diesel engines also need a pre-lubrication and warm-up process to ensure that the oil pressure, oil temperature, and cooling water temperature of the emergency loading meet the technical conditions of the product; the pre-lubrication and warm-up process can be carried out in advance according to different situations.
(5) Maintenance and repair of emergency diesel generator sets
Emergency generator sets should be maintained and repaired regularly. Regular maintenance and repair should be carried out to ensure the normal operation of the generator sets. Regular maintenance and repair should be carried out to ensure the normal operation of the generator sets. Regular maintenance and repair should be carried out to ensure the normal operation of the generator sets. Regular maintenance and repair should be carried out to ensure the normal operation of the generator sets. Regular maintenance and repair should be carried out to ensure the normal operation of the generator sets. Regular maintenance and repair should be carried out to ensure the normal operation of the generator sets. Regular maintenance and repair should be carried out to ensure the normal operation of the generator sets. Regular maintenance and repair should be carried out to ensure the normal operation of the generator sets. Regular maintenance and repair should be carried out to ensure the normal operation of the generator sets. Regular maintenance and repair should be carried out to ensure the normal operation of the generator sets. For instance, emergency units for military communications, important foreign affairs activities in large hotels, large-scale public building activities during the night, and important surgical operations in hospitals should be in a state of pre-lubrication and warm-up at all times, so as to be able to start up quickly at any time and minimize the time of power failure due to faults.
For more questions about the generator set, please call the Beidou Power team. More than ten years of professional production and sales of power generation equipment experience, more professional engineer team to serve you, choose Beidou power is to choose rest assured, welcome on-site factory inspection.
Post time: Aug-31-2026