# Timer questions



## MDShunk (Jan 7, 2007)

How do you plan on bringing the timing selection feature to the front panel? I hope you're thinking about using something like this:










and NOT something like this:


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## subelect (Nov 25, 2007)

I am not sure what you mean when you write "front panel". 
The first job is for an irrigation motor; I am going to install a small 3R panel with a hinged door so the farmer can open the door to adjust time with a small degree of safety. He may be adjusting time twice a day all summer long.
The second job is for a concrete mixing plant. The wiring, raceway and control panels are already installed. Once I get the time set correctly, they should not have to adjust the time again. 

Why do you prefer the first timer pictured? Is there something that I need to avoid?
Rick


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## Jlarson (Jun 28, 2009)

The first one is made to be panel mounted through the enclosure or a swing out sub panel inside so you don't have to have the live parts exposed while you fiddle with the times. 

Although farmers don't really bother themselves with such saftey things so :whistling2:


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## mrmike (Dec 10, 2010)

subelect said:


> I have two separate jobs involving timers coming up this week. I was spoiled in the Navy: simple Agastat timers with basic NO or NC contacts. I have a heck of a time keeping the Square D timer applications straight.
> 
> First job: replace an existing START/STOP setup with a HAND-OFF-AUTO (not a problem) and in the HAND position, the customer wants to have the motor operate for a variable amount of time that he sets and then shut off.
> I plan to install the H-O-A switch and leave the START/STOP station in place, except use the START switch to provide the toggle for my timer.
> ...




Eagle Signal - Danaher Specialty
Preset Timers, B506 RESET TIMER Series Operating Voltage: 90~240 VAC, Mounting: Panel Mount, Timing Range: 0.01 Seconds ~ 9999 Hours, Display Type: LED, Termination: 11 Pin, Enclosure: IP65, Approvals: UL


On your second application, you will also need an off delay. This timer that I show here one like I used in industry & it can do just about everything you want to do. You can program the off delay for whatever time-then it times out-then your preset on -time starts and times out-then it RESETS back to your off time & starts the cycle over again.
On & off times can be changed anytime.

On the first application it looks like your going to have to "latch" in a relay in the "hand" mode when the operator hits the start button........


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## subelect (Nov 25, 2007)

I had a few minutes this morning on job #2 so I decided to try out the timer ckt.
Long story short, I have 55 volts to ground on the control wire from the NO contact to my timer, with both ends of the same wire disconnected. I could not figure out why the timer would not start the timing cycle. The voltage goes away when I turn off the control power (only power in that control panel).
I checked the voltage on the wire both with my Fluke 116 & my brand new Fluke 376. I have a tough time believing that it is not an induced voltage (no voltage indicated on my 1" IMC between the panels, no tripped ckt. bkr, there is an EGC in the raceway), but it is keeping the timer from operating. 
I pulled the wires into the conduit, and I know that I am not perfect, but at least I know that if something did go wrong, I am the one to blame. 
This project is not starting out well. 
Rick


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## JRaef (Mar 23, 2009)

Your first application is conceptually correct, but what you do is put the NOTO (Normally Open, Time to Open) contact in series with your seal-in for the Start button. Don't put it ahead of the contactor coil because then your Auto function will not work.

For the 2nd application you w3ant what is called a "One Shot" timer function. Momentarily close the initiate contact and it changes state, the timer starts and when the time expires, the load contents go back to normal. You can do this with an Off Delay as well, the difference is that an Off Delay will not begin timing until you LET GO of the initiate contact, whereas a One Shot begins timing immediately regardless of what happens with the initiate contact.


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## ScooterMcGavin (Jan 24, 2011)

For problem number two you can still use your time delay on relay to control the timing but you will need a control relay to seal in from the momentary start button. The drawing shows the load controlled by the contacts on the control relay but you could come off another set of NC contacts on the timing relay and achieve the same result.


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## JRaef (Mar 23, 2009)

scameron81 said:


> For problem number two you can still use your time delay on relay to control the timing but you will need a control relay to seal in from the momentary start button. The drawing shows the load controlled by the contacts on the control relay but you could come off another set of NC contacts on the timing relay and achieve the same result.


Yep, that's a good work-around if you already own an On Delay timer and you have another control relay available. That circuit by the way is exactly what is going on inside of a "One Shot" timer.


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## dogleg (Dec 22, 2008)

I tried to do problem #1 with a timer (Dayton ,multiple function ,multiple range)set it to off delay and set a time.Wired the start button to 5&6(initiate button)and used a NO contact in series between 3 and coil.When you push the start button the contactor pulls in and the timer does its thing and it turns the starter off.However this makes the stop button useless in the Hand mode.Is this right? Would anybody care to draw this out on a one line with the HOA.It would help me to see if I'm thinking this correctly.Thanks in advance.


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## ScooterMcGavin (Jan 24, 2011)

The easiest way to get the timer to stop early is to wire the constant input power for the timer downstream of the stop button. That way when you hit the stop button the power will drop out to the timer and drop the relay out.


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## dogleg (Dec 22, 2008)

Next time I'll draw it out before post a dumb question,that was an easy fix. Next?


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## Wirenuting (Sep 12, 2010)

dogleg said:


> Next time I'll draw it out before post a dumb question,that was an easy fix. Next?


No question is dumb.
Stupid answers are a norm. But any question is a good one as we learn from asking.


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