Product name：PE type motor pre-start purge control system
PE type motor pre-start purge control system
The Pe-type motor pre-start purge control system (hereinafter referred to as the purge control system) is mainly used for increased safety Ex e, non-sparking Ex n, and non-flammable motors. As a measure of increased safety, through pre-start Purge to reduce the concentration of combustible gas that may exist in the housing before the motor starts below the safety line.
This system can not only be applied to the internal ventilation and purge control of large motors in hazardous locations, but also can be applied to the internal ventilation and purge control of other electrical equipment. The system can quickly purge the motor by controlling the purge pressure, purge flow and purge time. Flammable gas that may exist inside before starting.
For electrical equipment working in Zone 2 specified in GB3836.14-2000, explosive mixtures in the form of gas, steam, mist (if they occur only occasionally and exist for a short time) or explosive dust mixtures (only in the normal operation) It may only appear in a fault state). In this case, the electrical equipment pre-start purge system can be used to ensure the safe operation of electrical equipment.
The explosion-proof performance of the purge control system complies with GB 3836.1-2010 Electrical equipment for explosive gas atmospheres Part 1: General requirements, GB 3836.2-2010 Electrical equipment for explosive gas atmospheres Part 2: Explosion-proof type
, GB 3836.3-2010 Electrical Equipment for Explosive Gas Environment Part 3: Increased Safety "e", GB 3836.4-2010 Electrical Equipment for Explosive Gas Environment Part 4: Intrinsically Safe "ī"
Explosion-proof mark: ExdⅡCT6 Gb
Principle and Selection Guide
The main control unit of the Pe-type motor pre-start purge control system controls the supply of compressed gas and confirms the purge flow, pressure and time. The pressure relief unit serves as a safety outlet for the purge gas of the equipment and provides a signal to confirm the flow parameters of the gas in the motor cavity. The motor pre-start purge control system is based on the motor model. After setting the purge flow and time, it can ensure that the gas in the housing completes the required purge and ventilation volume for safety before the motor is started each time, avoiding manual operation Unreliable factors, when the ventilation is completed, it is linked with a signal (contact switch or pneumatic signal) to send out the motor start permission.
The user should select the purge flow according to 5 times the volume of the electrical enclosure when selecting the model. In general, the shortest purge time requires 15 minutes, the longest requires 45 minutes, usually 30 minutes. For example: the volume of an electrical equipment enclosure is 12000NL, and the calculation method of purge flow is: 12000NLX5/30min=2000NL/min. It is more appropriate to select 2000 NL/min for the flow rate of the purge orifice. The definition of electrical enclosure volume in GB3836.52004 Item 3.5 is the volume of an empty enclosure without built-in equipment. For rotating electric machines, it means the net internal volume plus the volume occupied by the rotor.