Safety issues during the turning gear operation
Thread Content
During pump operation, the standby pump needs to be rotated periodically. However, the motor is still powered on during this process, and the pump may be interlocked. In such cases, should the interlock be disabled before rotating the pump, with the motor’s power supply turned off first? Otherwise, if the pump starts suddenly during rotation, safety cannot be ensured. Or maybe such pumps don’t even require rotation? Failing to rotate them is detrimental to the equipment; I seek advice from those with more experience.
Why isn’t it powered off? It will have no impact on security. Generally, a dedicated turning device is installed, which does not affect the entire unit or its interlocks and similar systems
Our approach: Disable the automatic start function of the backup pump, so that it is in a disabled state – neither in manual nor automatic mode. Then perform the pump rotation; once this is completed, re-enable the automatic start function. It’s important to note that it’s sufficient to inform the control room before starting the pump rotation, so that in case there are problems with the operating pump, the control room can alert you to stop the rotation immediately and activate the backup pump.
I guess he was referring to the pump, not the compressed turntable. I think setting the pump to the local position will prevent it from starting as a result of interlocks or accidental operations by the main control system! Pumps generally have three positions: local, remote, and interlocked
I have no experience in operating such equipment; I offer the following suggestions – do you think they are feasible? It is recommended to disable the interlock of the standby pumps during cranking, then cut off power to rotate them on a rotational basis (all standby pumps should be rotated once a week as per a planned schedule), so that some of the standby pumps are rotated every day – this ensures safety without affecting the normal operation of the plant. Last edited by Hunter on 2009-2-22 15:14]
This method is very safe, but the operator will scold you for doing it this way... What we do is set the interlock for the standby pump to manual mode; after rotating the pump shaft and ensuring that it is no longer rotating, we then switch the interlock back to automatic mode (of course, the control room needs to be informed in advance). This prevents the pump shaft from starting to rotate again after rotation, which could generate an induced current and cause the standby pump to switch to automatic mode automatically (this has happened before). Is it safe and easy to use? ?
For pumps, as the people above mentioned, my usual approach is to engage the interlock to cut off power, or manually switch the switch to the “manual” position; after turning the pump, I reset it to its normal state. Additionally, before turning the pump, I use a walkie-talkie to check in and inform the personnel in the control room, so as to avoid any potential injuries. As for whether it is necessary to rotate the standby self-priming pump, I believe flexibility is key in this regard. In my facility, we carry out regular rotation once a month, while in other places the switch is switched to the “manual” position on a daily basis, and it is reset after the rotation is completed. There’s nothing really right or wrong, or appropriate or not.
For pumps without an automatic start interlock: rotation can be carried out directly; for pumps with such an interlock: the control lever should be moved to the manual position, and after rotation is complete, it should be moved back to the automatic position. The direction of rotation should be the same as that of the pump, and the force applied should be such that it facilitates operation, preventing hands or tools from being caught in the mechanism as the pump rotates.
Thank you for all your suggestions. It seems that turning the machine manually is necessary, but first the interlocks need to be disabled. Sometimes, between safety and the level of complexity involved, safety must take precedence
Cranking the machine is necessary; you just need to change the button of the spare pump to manual mode, and that’s it! ·That’s exactly what we do! ~
This is how we do it: deactivate the interlocks, turn the gearshaft, and then supply power
What if the pump starts suddenly? What should I do? Still power-off, safe.
First, inform the control room of the tag number of the pump that needs to be rotated. Then move the button on the control panel to the manual mode; there are interlock mechanisms in place, so power should be cut off where necessary. Be careful not to hurt your hand while rotating the pump. It is best to have two people work together on rotating the pump, or use specialized tools for this purpose. Always pay attention to safety; if the pump gets stuck during rotation, contact the maintenance team immediately for repairs – do not use force.