Help needed wiring repeat cycle timer?

Discussion in 'The Projects Forum' started by BFG, May 18, 2011.

  1. BFG

    Thread Starter New Member

    May 18, 2011
    5
    0
    Hi everyone, thanks for having a look.

    I'm a bit stuck, I've bought a repeat cycle timer which I need help wiring. Its purpose is to time a humidifier for mushroom growing (he he, not that kind). I chose this route due to the shortage of plug and go type products in the UK (under £150 anyway).

    I managed to source a secondhand Cycle timer unit, with a base, from Ebay at a good price

    I've clearly come unstuck however, as I can't make sense of the electrical diagram on my secondhand unit, which I'm sure is telling me how to wire it.

    I have scanned the diagram and uploaded it below. It is a 'Syrelec' repeat cycle timer MDR.U (Rs. Part 260-599), which is discontinued. In fact I think the company was liquidated.

    If anybody could advise I would be most grateful.

    My theory so far, is that 2,7 & 8 make up the circuitry powering the timer unit, and 4,3 & 1 is somehow the connection for the circuit to be made. I was planning on rigging the unit up to a 24v PS to try and determine its function.

    Thankyou for looking, and thanks to anybody who can shed some light on this. :)

    This is the ebay listing of the timer:

    http://cgi.ebay.co.uk/Syrelec-repeat-cycle-timer-module-MDR-U-RS-PT-260-599-/290559728007

    PS - Sorry if this is in the wrong forum section, I know it doesn't quite qualify as a project, but it is in no way homework help...
     
  2. KJ6EAD

    Senior Member

    Apr 30, 2011
    1,425
    363
    Terminals 2 & 7 are timer power. The link to terminal 8 is probably to select single cycle or repeat cycle operation by it's presence or omission. Terminals 1, 3 & 4 are obviously the output contacts.
     
  3. BFG

    Thread Starter New Member

    May 18, 2011
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    Thankyou for your reply!

    I know it doesn't look good, registering just to get my question answered, whilst unwittingly overlooking the etiquette sticky at the top of the board. Very grateful that you were able to help me out, nonetheless. :)
     
  4. BFG

    Thread Starter New Member

    May 18, 2011
    5
    0
    I am starting to think that the bridge between terminals 8 & 7 is required when supplying 24V AC/DC, however not required for 230V AC.

    I have inferred this from the message:

    "Voltage 24V AC/DC: Link 7-8"

    Which is also repeated in French immediately above it (with a makeshift/possibly french symbol depicting AC/DC).

    Does this sound like a possible configuration? Or is this a ridiculous notion?

    As I now understand it, the components used in 24V circuits are often not compatible with those that would be used for 240V. I first thought that this goes against my theory, but in retrospect I believe it supports it. It would make sense that there are 2 circuits, each designed to work at their own voltage. Bridging the terminals would appear to be a method of switching between the circuits manually.

    Hmm... I'm quite keen on the theory. Does it sound likely to you?

    I previously neglected to mention that there is a toggle on the side of the unit to switch between the two operating functions of repeat and single cycle. @ KJ6EAD Sorry for not realising this earlier.

    Thanks for reading, thanks in advance for any input! :)

    Edit: Sorry for double post, I assumed auto-merge would take charge.
     
  5. williamj

    Active Member

    Sep 3, 2009
    180
    32
    BFG,

    As KJ6EAD stated above terminals 2 & 7 power the timer with 24VDC. (Pay attention to polarity.) Terminals 1, 3 & 4 are for the timed circuit and can handle up to 250VAC at a maximum of 10 Amps.

    Through terminal 1 & 4 (terminal being the power in and terminal 4 being the first power out) you can power something before the timer times out and then, when the timer does time out, power something else through terminals 1 & 3 (terminal 3 being the second power out) using up to 250VAC drawing no more then 10 Amps.And when the timer resets the something through terminals 1 & 4 will be powered again.

    williamj
     
  6. KJ6EAD

    Senior Member

    Apr 30, 2011
    1,425
    363
    Yes. That sounds right. I hadn't noticed before. :confused:
     
  7. BFG

    Thread Starter New Member

    May 18, 2011
    5
    0
    Thanks for your reply.

    What makes you think that the power supply to the timer itself must be 24VDC? From the information on the side, I gathered that the entire unit is capable of operating at either 24V AC/DC or up to 250V AC.

    Thanks for your suggestion for terminals 1,3 & 4. The function you have described is exactly as I presumed.

    My fault for not mentioning the function switch on the side of the unit.

    Thankyou both!
     
  8. williamj

    Active Member

    Sep 3, 2009
    180
    32
    BFG,

    I could be mistaken but at terminal 2 there is a pos. symbol (+) and to me that indicates polarity. Seeing that AC has no "polarity" I assume it must indicate DC. And in a DC circuit when a positive symbol (+) is give it indicates that that is the polarity that must be followed. Not being familiar with that particular device I could be mistaken

    It may very well be both AC and DC compatable. If it is, it is most likely after my time (now retired). You could test it with 24VDC to see if it operates correctly.

    good luck,

    williamj
     
  9. BFG

    Thread Starter New Member

    May 18, 2011
    5
    0
    Excellent, thankyou. I thought I understood what you meant, when you used the term 'Polarity' in your first post. I was wrong.

    Its observations such as those you have just made, which get overlooked by people like me with little to no background knowledge.

    OK, so this indicates the direction of the electric charge in the event that 24V DC is used. This annotation (+) would be required if the unit ran on DC alone, but it would still be required if it was able to run on both AC and DC (in the event that it is run on DC).

    What I'm trying to say is, does it actually rule out the AC & DC use? or is it simply instructing how to connect if DC is used?

    I have a 24V AC transformer which I planned to use to test the component. The main reason I ask, is because I will have to purchase a 24V DC transformer to test safely if this is true.

    I know, ultimately, I could just run it from a 24V DC source and then I would have no further issues. If I can't reach a solid conclusion, than I will simply buy a 24V DC source... I'm just being tight.

    EDIT: Having re-read your post, I think I'm asking too much to expect an answer to any definite level. As you quite rightly say you don't know the component at hand... Speculation welcome though! Thanks again!

    EDIT 2: In retrospect, I think the only way to know for certain is through testing. I can use a 24V DC supply to try switching the 2 voltages, with terminals 7 & 8 both connected/not connected.

    * If the timer can switch both a 24V DC and a 240V AC current, whilst being operated with 24V DC and terminals 7 & 8 bridged: I would assume that terminals 7 & 8 relate only to the supply voltage, not the current being switched. From this it would make sense that the actual timer is compatible with both supply voltages, and I would feel comfortable testing it with 240V AC.

    I will post back my results from testing in a few days, comments/suggestions still welcome! Thankyou!
     
    Last edited: May 19, 2011
  10. jj1960

    New Member

    Feb 4, 2013
    3
    0
    i realise this post was a while ago and i was wondering if you had any success
    i am able to get the same timer
    i would like to use it to switch an 240 volt appliance on for 6hrs and off for 12hours on for 6 off for 12hrs continually
    would this do the job and if so could you help as to how i connect it up
    thanks
     
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