Adding to Emergency Stop Circuit

[Sunny_92]

I am helping with a bid for an industrial customer who would like to monitor the temperature of the hydraulic pumps and tanks on a certain piece of equipment, and shut down the equipment if the temp gets to high. I have already found a suitable IR camera for this purpose, but I'm questioning the best way to perform the shutdown. The equipment already has an E-Stop button. Would we violate any codes by placing normally-closed relay contacts in series with the E-Stop button? The other option I see is shunt tripping the breaker that feeds the equipment, but that would probably be more expensive.

Any input is appreciated, thanks!

 

[petersonra]

I am helping with a bid for an industrial customer who would like to monitor the temperature of the hydraulic pumps and tanks on a certain piece of equipment, and shut down the equipment if the temp gets to high. I have already found a suitable IR camera for this purpose, but I'm questioning the best way to perform the shutdown. The equipment already has an E-Stop button. Would we violate any codes by placing normally-closed relay contacts in series with the E-Stop button? The other option I see is shunt tripping the breaker that feeds the equipment, but that would probably be more expensive.

Any input is appreciated, thanks!

I don't think what you are proposing violates any codes.

Depending on just what equipment this hydraulic system feeds and how it works, tripping the e-stop may be OK or it might be the dumbest idea ever.

I can't recall a hydraulic pump system that I have worked with that did not have some kind of temperature monitoring on it already, usually temperature switch(es). Is this some kind of home brew system?

The reality is that a high temperature is not really an emergency and if you just feed the signal into the control system to shut down the equipment more normally it may have less negative consequences than an abrupt shutdown like you are proposing. A big red beacon that comes on to alert the operator to the condition might be all that is needed.

ETA: It may also be appropriate to take some action other than shutting off the equipment if a high temperature is detected.

 

[Sunny_92]

I don't think what you are proposing violates any codes.

Depending on just what equipment this hydraulic system feeds and how it works, tripping the e-stop may be OK or it might be the dumbest idea ever.

I can't recall a hydraulic pump system that I have worked with that did not have some kind of temperature monitoring on it already, usually temperature switch(es). Is this some kind of home brew system?

The reality is that a high temperature is not really an emergency and if you just feed the signal into the control system to shut down the equipment more normally it may have less negative consequences than an abrupt shutdown like you are proposing. A big red beacon that comes on to alert the operator to the condition might be all that is needed.

ETA: It may also be appropriate to take some action other than shutting off the equipment if a high temperature is detected.

Thanks for the input. The equipment is a large baler at a recycling facility, not some home brew system. I don't know if it has any temperature monitoring built in, but I guess the facility personnel are extra concerned about fire because of all the paper scraps around. Looks like I might want to reach out to the baler manufacturer to get their input.

 

[petersonra]

Thanks for the input. The equipment is a large baler at a recycling facility, not some home brew system. I don't know if it has any temperature monitoring built in, but I guess the facility personnel are extra concerned about fire because of all the paper scraps around. Looks like I might want to reach out to the baler manufacturer to get their input.

I think it is unlikely that it would get hot enough to start a fire.

Is this a problem they actually have or has someone created a problem that does not actually exist? If the equipment is overheating, it seems like the thing to do is fix that problem rather than trying to put a Band-Aid on it.

 

[Jraef]

Thanks for the input. The equipment is a large baler at a recycling facility, not some home brew system. I don't know if it has any temperature monitoring built in, but I guess the facility personnel are extra concerned about fire because of all the paper scraps around. Looks like I might want to reach out to the baler manufacturer to get their input.

I would, because as Bob said, it is VERY common for hydraulic power units to have system to detect High Discharge Oil Temp and sometimes the proper response is to continue running in bypass so that the oil has a chance to go back into the receiver to cool rather than shut down immediately and risk a blow out.

Also, if you tie ANYTHING into the E-Stop circuit, you are adding your name to a list for the lawyers if anything goes wrong, whether or not your circuit was involved. I was involved in a suit like that early in my career, for a cardboard baler in fact. An operator got his sleeve caught and was getting pulled in, the E-Stop and main disconnect had been wired wrong so it didn't kill power to the auger and the guy lost his arm. The company that hired me to investigate what happened had no fault in this because they had not actually wired anything, they only mounted the parts in the panel but the baler OEM wired it to save themselves money. The legal bills to prove they had nothing to do with it still cost them a ton of money.

 

[Belevolk]

Using a camera?

Using a camera?

I do not even know how to get colors in a camera to cause a trip function.

For your consideration, thermal couples connected to a Panelmate or similar. Programing the screen function is easy, the PM will do the math for you, you could trend as to temps. Depending on what you purchase there would be plenty of I/O to do the job including a light/ horn warning device which would sound before the unit went nuclear.

This gets everything hard wired, no consideration for smoke/fumes or broken hoses to obstruct the field of view.

 

[FionaZuppa]

ez pz.

Omega is your goto shop for everything you need. they have tape on, bolt on, screw in, clamp between, everything TC's, and all the gear needed to monitor/alarm/alert.

http://www.omega.com/guides/thermocouples.html

their support is top notch. give them a call, tell them what you need to do, and they will help you choose the components required.