Variable-frequency pump started
Thread Content
After a variable-frequency pump loses power, if it is started again immediately, is it necessary to close the outlet before restarting? Can it still be started with the outlet valve open?
The motor load of a pump started with variable frequency rises relatively slowly in accordance with the pump’s load; therefore, the starting current does not reach around 10 times the normal current. As a result, it is possible to start the pump immediately after power is restored, without the need to close the pump’s outlet valve
Determine which pump to use; regardless of whether it is a variable-frequency pump or not, follow the operating requirements for starting the pump strictly
It’s not clear enough; after a power outage, we treated it as an accident. We need to close the outlet of the pump, and then start it following the normal startup procedures for pumps. If it’s just a brief lightning strike, I think there’s no need to close the pump’s outlet
1. Ordinary pumps generally have a power-off protection function; if there is a power outage for more than 3 seconds (the specific duration can be set electrically), it is considered a power outage, and the pump should then be started using the normal starting procedure. 2. Another issue is that most variable-frequency pump systems come equipped with a protection feature: once the pump stops operating abnormally, a switch in the electrical system must be closed before it can be restarted. Therefore, if it stops operating, you can’t just make it start working whenever you want! In summary, if a variable-frequency pump is used under normal conditions, in the event of a power outage or voltage fluctuation, it is necessary to activate the fixed-frequency pump as soon as possible to ensure that production can be resumed promptly!
What I mean is, a power fluctuation usually lasts just over 10 seconds. If operating at the power frequency is required, it is necessary to shut down the inverter output and then turn on the power-frequency output, which takes some time; however, if it is possible to start the system without shutting down the inverter output, it saves time that can be used to address other issues. .
It can be started directly in emergency situations, and some small centrifugal pumps can also be started directly in the event of power fluctuations.
After a variable-frequency pump loses power, if it is started again immediately, the outlet must be closed; the frequency should only be changed after normal operation at the fixed frequency.
What’s not allowed in special cases? It’s completely fine not to close the pump outlet.
Under normal circumstances, operations should be carried out strictly in accordance with the procedures. Otherwise, the motor will get damaged. It’s one’s own responsibility then. If under special circumstances and with the leader’s permission, it can be initiated
Check what type of pump it is. If it’s a centrifugal pump, the outlet needs to be closed; centrifugal pumps can handle pressure buildup. If it’s a gear pump, there’s no need to close it completely in order to prevent pressure buildup