11-Pin Timer Technology

I have recently moved from the Sawmill industry back to the Oilfield by accepting a job maintaining gas plants and wells within a 2 hour driving radius of the main plant. I am so used to almost everything being Allen-Bradley PLC 5s or SLCs that I am having to learn a lot of old school stuff that hasn't been upgraded at these 24/7 plants.

As well as the above systems, I am learning SLC 150s and PLC-2 as they are all over the place here. In addition, there are still plently of complex processes run with banks of relays and real-world timers.

Which brings me to my next question. I am trying to find a cheap 11-pin timer that will time for 5 minutes after a bypass button is pushed that will pulse the output every second for that 5 minutes. What we have is a vibration detector with a 30 second startup bypass. We want to extend this to 5 minutes, and the input to the detector will only bypass for longer than 30 seconds if you reset it (the pulse). In other words we want to effectively continue to restart the bypass until 5 minutes has passed.

I know I could do it with 2 timers, One 5 minute timer driving a 1 second timer, but is there something fancier out there that will fit in my 11-pin base? Space is pretty tight in our x-proof enclosure. We have 24v for control.

Thanks,
Vetteboy

I think you're stuck using 2 timers...

Those multi-function timers have some pretty interesting choices, but I doubt you'll find one that will give you the combination you need.

Consider using miniature timers like THESE from Omron. Two of those will probably take up less space than your current 11-pin socket.

Or you could possibly use one of those 'cube' timers (wired in series) for the pulse function. HERE'S a link to what I mean by 'cube' timer. You can probably find a home for one of these on the side of the enclosure.

Also remember that the 'smart relays' are pretty darn small. You may be able to use one of those and replace a handful of other 'space hogging' components...

beerchug

-Eric

Try this link


http://62.110.11.151/pdf/UK/DCB01CM.pdf

Greetings,

I found in the Grainger Book, a SQ D model #9050JCK70V14. Grainger part number 5B383. I hope that helps

Ed

Vetteboy needs a SPECIAL timer, fellas!...

I thought about this a little more, and now I'm wondering if it might be possible to use a COUNTER rather than a timer. Look at THIS data sheet.

I haven't thought it through, but taking advantage of the 'total' counter (page 18) might work. With the 'preset' set to zero, the first output should fire off immediately on powerup (I think?). You can set the first output to give a 1 second pulse, which can bypass your detector, AND reset the counter. Hopefully, the counter would turn on the output again (similar to a repeat cycle timer). Meanwhile the 'total' counter is keeping track of how may times this happens. It would be set to whatever value gives you 5 minutes of pulses. When you reach the 'total' preset, the second output turns ON (I don't know if this is how it works). If the N.C. contact of the second output was in series with your bypass, it would inhibit the bypass, preventing further pulses (even though the first output continues pulsing).

I HIGHLY doubt this counter works as I describe, but I figured I'd mention it anyway. It might spark other ideas...

beerchug

=Eric

In the old days, we had good luck with Omron timers. It looks to me like you need an on-delay timer and a repeat cycle timer.

Frankly, you could probably do what you want cheaper with a mcro-PLC like the AutomationDirect.com DL-05 or a programmable relay like the Allen Bradley 1760-Pico. this is especially true if you need a bunch of these, or if you need some flexibility in the controls.

Tom Jenkins said:

Frankly, you could probably do what you want cheaper with a mcro-PLC like the AutomationDirect.com DL-05 or a programmable relay like the Allen Bradley 1760-Pico. this is especially true if you need a bunch of these, or if you need some flexibility in the controls.

Click to expand...

I totally agree.... We keep a number of DL05s on the shelf and almost automatically use them to replace timers, counters, steppers, double latching relays, etc..

I have to agree with Tom and elevmike. My choice would probably lean to the pico/easy unit, because of size and flexibility, and if need be, wired into a 11-pin male. However, the 1 second pulsing might be easier with the micro.

AD has qite a selection of timers for $29-39, and fairly small in size.

When I started with diesel engine controls in 1972 some panel manufactures were still using plug-in thermal timers (vacuum tube with a heater and bi-metallic strip). Caterpillar had an econo panel, where the thermal heater wasn't even enclosed. Thank goodness for progress.

regards....casey

Casey,

Talking about timer technology, we still have equipment running that's 80 to 100 years old. Many use dashpot timers (oil check on the coil) and pneumatic timers with leather seals. The really advanced timers are clock motors that turn a shaft with a number of cams and contacts. I'm amazed at how resilent this stuff is, and I doubt that any upgrade will last half as long.

elevmike:

How quickly I forget. Around here, there are only a couple of buildings over 2 stories in the multiple county area. The new library has, of course, a new elevator. Same with the hospitals.

Do remember some really nasty ones in Peoria in Pabst, ComEd coal fired plant, and a few others.

My hat is off to you for keeping them runnung.

I put in for a project update a natural gas line, so I may be in the same boat as vetteboy. Doesn't pay well, but the equipment is a little more modern. Upgrading series 6 to 9070's.

regards to all.....casey