Emergency Stops

[EvanT]

We use industrial mixers in our operations. The mixers are low hazard in that they have a turbine at the bottom of the tank which can only be accessed through a man hole. The mixers are operated by a PLC which has a general stop button but they currently do not have any E-stops at the point of operation. Do we need to install E-stops or is it just a good idea (Should vs. Shall)?

Thanks

 

[just the cowboy]

E stop stops ALL

E stop stops ALL

It depends on your operation. An E stop should only be used in an emergency situation and it should stop ALL operations from the PLC or area. A stop may or may not be needed at point of operation. Most tank room I have seen have an E stop near each entrance so everything pumps, mixers and other equipment can be shut down all at once in an emergency.

 

[gadfly56]

We use industrial mixers in our operations. The mixers are low hazard in that they have a turbine at the bottom of the tank which can only be accessed through a man hole. The mixers are operated by a PLC which has a general stop button but they currently do not have any E-stops at the point of operation. Do we need to install E-stops or is it just a good idea (Should vs. Shall)?

Thanks

I am not aware of any NFPA code or standard that requires E-stops for such equipment. There may be something from OSHA that either directly or through the "general duty" clause that could require them. Many companies adopt policies that go above and beyond code requirements, but if you are a small company I'd assume you're already aware of them.

I would file this under the "good idea" folder.

 

[petersonra]

We use industrial mixers in our operations. The mixers are low hazard in that they have a turbine at the bottom of the tank which can only be accessed through a man hole. The mixers are operated by a PLC which has a general stop button but they currently do not have any E-stops at the point of operation. Do we need to install E-stops or is it just a good idea (Should vs. Shall)?

Thanks

I would suggest this. NFPA79 requires an estop at each operator station. While your situation may not fit NFPA79 perfectly, as a guideline it is a pretty good idea. Personally I agree it probably does not matter much as the risk is pretty low, but there is nothing that says you have to have an elaborate safety relay system as part of the estop. having said that, if you decide to install them claiming compliance with NFPA79 you should probably comply with all of the related stuff in NFPA79.