question about momentary switches

[Night65]

is there a momentary switch that i could hook up using 120v to work a contacter for 20 seconds

 

[mdshunk]

Sure. An A-B pushbutton would do the trick. If you want a device mounted style, many of the switch manufacturers make a switch that looks like an ordinary snap switch but is momentary.

 

[480sparky]

P&S makes a 'gargabe disposal' switch in decora.

TM870-xxxxx.

 

[Night65]

thanks for helping

thanks for helping

i forgot to mention, it has to be water-proof, not weather proof, but water tight it's going in a car wash. I have a box that i probably will have to change but the switch can be any style as long as it is water tight and 120v, if you can where can i get one

 

[cadpoint]

Sorry, I'm stuck on the time specific thing .


Maybe:
A FX box and a little red slap switchcover.

 

[BackInTheHabit]

Use the momentary switch to control a timing relay that controls your contactor. If it's cost effective that is.

If you want water tight, get an approved box to mount them in.

http://www.ab.com/industrialcontrol...eneral_purpose_timers_and_counters/700ff.html

 

[hillbilly1]

Use an "on delay" relay to break the power to the contactor coil using the normally closed contact, break power to the relay thru a normally closed momentary 16mm, 22mm, or 30mm pushbutton in a nema rated enclosure for that enviroment, all can be 120 volt. Set timer for 20 seconds, push button, contacts will remain closed for 20 seconds, then open dropping out contactor. Beforwarned though a power failure will rest timer and activate load. Do not use if this is going to be a problem. They also make a pnuematic timer with built in pushbutton, but is large and bulky,hard to find, but will not have the unwanted activation problem. There are other types of timers that could be used, but this is the simplest.

 

[don_resqcapt19]

I think Allen Bradley still has pneumatic timing contact blocks for thier push buttons. You push the button and the contact stays closed until it times out. Their buttons and boxes are available in NEMA 4X so that should be suitable for the application. You would have to check on the current rating of the contact block compared to the requirement of the load.

 

[Jraef]

I also am not sure what you meant by the timing issue. If you mean, "Can I hold a momentary contact in for 20 seconds with my finger?" the answer is Yes.

If you want to press a button once and have it wait 20 seconds before closing, or close immediately and stay closed for 20 seconds after you release it, then that is a different issue. You can either do it with a timing relay as described above, of you can get a timed contact block for Allen Bradley 800H series operators that has a pneumatic time delay built right in to the contact assembly. If you buy a N.O contact, #800T-XT, it will close 20 seconds after you push the button. If you buy a N.C. contact, #800T-XS, it will close immediately and re-open 20 seconds after you let go of the button.

Then you just buy whichever 800H Series operator you want to use.

http://www.ab.com/en/epub/catalogs/12768/229240/229244/2531083/tab5.html

Just be forewarned though, very few A-B distributors even know this product exists, you will not likely find it on the shelf. Plan on waiting for a factory delivery.

 

[Jraef]

I think Allen Bradley still has pneumatic timing contact blocks for thier push buttons. You push the button and the contact stays closed until it times out. Their buttons and boxes are available in NEMA 4X so that should be suitable for the application. You would have to check on the current rating of the contact block compared to the requirement of the load.

Heh, crossed in the internet ether...

 

[Night65]

thanks guys

thanks guys

if the nc #800t-xs is 120v then that might be what i'm looking for, what i'm trying to do is, remove a control box consisting of a contact, two time relays and a transformer, controlled by four different sets of on/off lighted push buttons, the reason is because the customer is sick of this old fashion ( meaning is not solid state equipment) going bad every year, it's in a car wash tunnel, the switches and the gear is behing a wall where the chemicals and pumps are kept ( alot of moisture ) so if i take the wire fed the the disconnect and pump wires put those on a general contactor plus the soleniod vlaves on a contactor and replace the push buttons switches with some kind of 20 second hold switch the the set up is simple and no more garbage componates to go bad every year.