Timer that can handle 1000 watts +

Discussion in 'Miscellaneous Equipment' started by Robert, May 31, 2003.

  1. Robert

    Robert Member

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    Anybody know of a timer that can handle 1000+ watts? One that is also cheap? I had a bit of a light bulb go off. When I've been copying some photographs I just flipped the lights on and off. No shutter on the lens. This works since the times are about 2 seconds. But if I could plug the lights into a timer then it would work even better. Obviously nothing fancy is needed. My Gralab 300 is limited to 750 watts so is shy of the power needed for the two 500 watt lights.
     
  2. Donald Miller

    Donald Miller Member

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    Robert, The simple and inexpensive way to handle this problem is to set a double pole,single throw, normally open relay -120 volt coil voltage. This relay should have contacts that will have 20 amp inductive load rating. It should be available from any appliance supply house. The wiring is as follows: Connect a pair of leads to one pair of the contacts (these will need to have a 115 volt plug on the other end as they will be plugged into a wall outlet when the wiring is finished). Connect your enlarger lamp to the other pair of contacts on the relay. Connect the enlarger lamp output from your timer to the coil of the relay. The relay should be mounted in an enclosure and ground wires connect from the wall outlet to the enclosure chassis, from the enlarger lamp to the enclosure chassis.

    This will shed the load from your enlarger timer and the enlarger timer will only need to carry the load of the relay coil (less then 150 watts). The relay contacts carry the load of the enlarger lamp. With a 20 amp inductive rating you will be able to handle enlarger lamp wattages of over 2000 watts.

    If you have questions on the wiring, you may contact me off post. Good luck.
     
  3. Loose Gravel

    Loose Gravel Member

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    The Metrolux timer/integrator handles 1200W and can be ordered with a special 16A relay if need be (16A x 120V = 1920W). This doesn't solve the cheap part, though.
     
  4. Robert

    Robert Member

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    To be honest electricty scares me-). I can change a light switch. Or a fixture. But I need to turn all the power in the house off first.

    I found a block heater timer. It looks like it can be set by the second [The display is in hours:minutes:seconds] but will likely be a pain to set each time.
     
  5. Robert

    Robert Member

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    I thought I would follow up.

    Gralab makes something called a contractor. It lets you put more power into the timer then the rated watts. Aristo [the cold light people] also sell a unit with the same name and features. I'm guessings it's just a gralab. I don't know how much the Gralab costs but the Aristo one seems to be about $100+ US.

    OTOH I picked up a second Gralab 300 on the cheap. Main reason was I wanted a backup and the price was less then even thinking about getting one fixed. Now you're going to ask doesn't this timer have the same problems? Yup but I can plug one light into each timer. Plug the timers into something like a switched power bar. The powerbar switch then becomes the one off switch for the timers. Obviosly this wouldn't work with a digital timer but with a pair of 300 it shoud be fine.