During thunderstorm weather, the frequency of the liquid oxygen pump increases automatically; please provide an analysis
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In the afternoon, there was suddenly thunderstorm and rain, which caused the frequency of the 2# liquid oxygen pump to increase automatically, leading to fluctuations in the flow rate and pressure of the liquid oxygen pump and resulting in pump shutdown. Is it possible that interference signals occur from the manual controllers during thunderstormy weather? Please provide an analysis regarding Air Liquide’s variable-frequency liquid oxygen pumps
What type of sealing is used in the liquid oxygen pump you are using? How long does it take to pre-cool once?
Pre-cool for two hours at a time. Mechanical seal + labyrinth seal
It depends on your control circuit; generally, the instrument sends signals to the electrical frequency converter, and rain may cause grounding issues.
Thank you first. Is it caused by poor electrical grounding? It has been running stably for over two years
Are there any connectors or junction boxes between the instrument and the frequency or speed of the electric liquid oxygen pump? Is it well waterproof? Our original liquid oxygen pressure also fluctuated when it rained, and it was later found that water was seeping into the wiring box; after addressing the grounding of the terminals, the problem no longer occurred!
On stormy days, when there are thunderstorms and electromagnetic interference occurs, an interference current is added to the Ao signal line generated by your DCS, causing your pump to be affected at a frequency of 100%. Check that the grounding of the DCS is not too close to your lightning protection grounding; the distance should be more than 20 meters. Check both ends of the AO wire; try to keep the wires covered by the shielding layer so that as little of them as possible is exposed. The Ao wire is grounded at the DCS side; it should not be grounded at the inverter cabinet.
Thank you very much; it’s a pretty reliable explanation. The instrumentation and electrical staff at our company have been unable to provide an explanation