alfiesauce
Senior Member
could they get away with the 10 second delay like I was mentioning? Or does it need to be an isntant off?
How can I make this work?????????
- Thread starter chevyx92
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chevyx92
Senior Member
- Location
- VA BCH, VA
That I'm unsure of. From what I understand when doors open, then fan shuts. This is all new for me so I am glad to learn about this for the future as I understand this is the current codes on new paint booths, from what I've been told.
alfiesauce
Senior Member
It's hard to understand how you could make something like this work without having either a- a delay on the doors so you can get in after the fan goes on or b- controls within the paint booth.
brother
Senior Member
Thinking of a different momentary switch
Thinking of a different momentary switch
Yes, but you have to 'push' the momentary in the other direction (like down for off, and up for on). The relay Im thinking of itself has 3 wires from it. One wire is the common the other 1 is either for the on, the other is for the off. Im thinking he can have the 'off' parrelled from a 'sensor' switch from the door when it opens. this way it only has the ability to turn it off' when opened.
The other 'switch' on the inside of the booth would be parralled off of both the 'on' and 'off' wires from the relay. So when they are inside they can turn it on/off whenever they want.
This is most inexpensive way that I can think of to do this. Shouldnt cost much. I can see this working, wish I was savvy enuff to put a picture up. Im gonna have to learn how to do that.
Thinking of a different momentary switch
Yes, but you have to 'push' the momentary in the other direction (like down for off, and up for on). The relay Im thinking of itself has 3 wires from it. One wire is the common the other 1 is either for the on, the other is for the off. Im thinking he can have the 'off' parrelled from a 'sensor' switch from the door when it opens. this way it only has the ability to turn it off' when opened.
The other 'switch' on the inside of the booth would be parralled off of both the 'on' and 'off' wires from the relay. So when they are inside they can turn it on/off whenever they want.
This is most inexpensive way that I can think of to do this. Shouldnt cost much. I can see this working, wish I was savvy enuff to put a picture up. Im gonna have to learn how to do that.
cadpoint
Senior Member
- Location
- Durham, NC
If you added the top circuit in parallel to the second circuit, from CR, Door, to Door, well is that it?
Aren't they asking for master control, and all conditions are met?
Wait the CR is in there is this an interface, Duh....
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chevyx92
Senior Member
- Location
- VA BCH, VA
Yes, but you have to 'push' the momentary in the other direction (like down for off, and up for on). The relay Im thinking of itself has 3 wires from it. One wire is the common the other 1 is either for the on, the other is for the off. Im thinking he can have the 'off' parrelled from a 'sensor' switch from the door when it opens. this way it only has the ability to turn it off' when opened.
The other 'switch' on the inside of the booth would be parralled off of both the 'on' and 'off' wires from the relay. So when they are inside they can turn it on/off whenever they want.
This is most inexpensive way that I can think of to do this. Shouldnt cost much. I can see this working, wish I was savvy enuff to put a picture up. Im gonna have to learn how to do that.
Yes we could do this but short of doing it we want to make sure everything is understood before we start buying explosionproof devices. I can make this work if I add A switch in the booth. The concept was to take the existing setup and make it work. I dont think I can without a delay timer. Thats seems to be the consesus.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
You're describing a latching relay. Temporary energizing in either direction.
So far, this sounds best. Low-voltage only in the booth, but there could still be contact arcing.
- Location
- Massachusetts
Perhaps this could be used inside the booth?
http://www.presair.com/air_switches.asp
http://www.presair.com/uploads/2008PresairBrochure.pdf
http://www.presair.com/air_switches.asp
http://www.presair.com/uploads/2008PresairBrochure.pdf
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brother
Senior Member
Ok, I reread your o.p. and I agree, for an 'existing' setup, a delay timer is all I can think of. It just sounded like you wanted them to be able to 'control' (have the option) this fan from INSIDED the booth. It just seems that a 'low voltage' switching inside would be the best option. I just dont like the start stops on the outside, what about emergency situations?? I did ask did they really need an e stop. Sounds like a 'code' violation in this type of set up to not have the e stop or the start stop availiable on the inside seeing the 'door' is only e stop in this sense.
- Location
- Massachusetts
Why would an air handler require an E-Stop?
brother
Senior Member
Ok, I thought maybe it was more, perhaps not.
alfiesauce
Senior Member
the purpose of the whole making the fan stop when a door is open is in case of a fire...
Fire means emergency
So maybe an emergency button is needed?
Fire means emergency
So maybe an emergency button is needed?
Hi,
Pardon if this was already mentioned I did not read all the responses.
I don't work in hazardous locations often, but would this work.
Use a low voltage (I believe inheriently safe) capacitive proximity switch inside near the door of the booth to operate a start relay outside. The operator could start the fan with a piece of cardboard. The relay would act like a momentary start PB in parallel with the outside start PB. Your 3 wire control for shut down would then operate as your client requires.
Pardon if this was already mentioned I did not read all the responses.
I don't work in hazardous locations often, but would this work.
Use a low voltage (I believe inheriently safe) capacitive proximity switch inside near the door of the booth to operate a start relay outside. The operator could start the fan with a piece of cardboard. The relay would act like a momentary start PB in parallel with the outside start PB. Your 3 wire control for shut down would then operate as your client requires.
frenchelectrican
Senior Member
- Location
- Nord'est Wisconsin et Paris France
Bob .,
If your spray booth do have make up air unit that must be interconnected to the main spray booth control and anytime the E stop or ANSUL system kicked in both must shut off itermetally.
One of my customer have this set up like that back in the state and it work pretty good.
Merci,Marc
How about using a time delay to bypass the door switches for the first 1 or 2 minutes of fan operation.
You start the fan, enter the booth before the time delay expires. If the doors are opened after the delay expires the fan stops.
OR
A latching relay that arms the door switches after the door opens the first time (on entrance to the booth) If the doors open again it shuts the fans down.
You start the fan, enter the booth before the time delay expires. If the doors are opened after the delay expires the fan stops.
OR
A latching relay that arms the door switches after the door opens the first time (on entrance to the booth) If the doors open again it shuts the fans down.
dbuckley
Senior Member
- Location
- Canterbury, New Zealand
Absolutely. Micro PLCs dont cost much, are quick and easy to program, and solve problems just like this one. And when you discover it doesn't work the way the customer actually wanted (even though it does exactly what the customer asked for), its easy to change.
brother
Senior Member
Do you know of any good 'plain english' books that would teach PLCs. I havent had chance to work with them much. would love to learn it.
I suggest an off-delay timer on the door switches.
Give it enough time to open and close the door without
killing the fan, if this is acceptable to the owners.
If the door stays open, the fan shuts down.
I think you are correct in not wanting to start
the fan with the door switches; the start-stop is safer.
Give it enough time to open and close the door without
killing the fan, if this is acceptable to the owners.
If the door stays open, the fan shuts down.
I think you are correct in not wanting to start
the fan with the door switches; the start-stop is safer.
dbuckley
Senior Member
- Location
- Canterbury, New Zealand
Dont know any good books on PLCs.
But just buy a micro PLC (under $100 probably) connect up a couple of switches and lights to the inputs and outputs and start playing. Start simple. Just connect (logically!) an input to and output so you turn the switch and the light comes on. Try an inverter, an AND relay, an OR relay, build a three way, try to figure out which element makes "an operate to go on, an operate to go off" toggle thing. Discover the fun of timers and the different types. A weekend of playing and you'll see control problems in a whole different light!
Many of the micro PLCs you can program directly using the LCD and buttons on the front of the thing. Make sure you get the manufacturers instruction book on how to use the thing, which cann usually be downloaded from the web site, but unless you like printing out a couple of hundred pages, grab the real thing.
But just buy a micro PLC (under $100 probably) connect up a couple of switches and lights to the inputs and outputs and start playing. Start simple. Just connect (logically!) an input to and output so you turn the switch and the light comes on. Try an inverter, an AND relay, an OR relay, build a three way, try to figure out which element makes "an operate to go on, an operate to go off" toggle thing. Discover the fun of timers and the different types. A weekend of playing and you'll see control problems in a whole different light!
Many of the micro PLCs you can program directly using the LCD and buttons on the front of the thing. Make sure you get the manufacturers instruction book on how to use the thing, which cann usually be downloaded from the web site, but unless you like printing out a couple of hundred pages, grab the real thing.
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