Patterson 2000D Enlarger timer

Discussion in 'Darkroom Equipment' started by dr5chrome, Mar 30, 2013.

  1. dr5chrome

    dr5chrome Member

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    Patterson 2000D - Anyone know the Watt handling capability of this timer? Doesn't seem to be listed anywhere.

    thanks - dw
     
  2. Ian C

    Ian C Member

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  3. dr5chrome

    dr5chrome Member

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  4. Nicholas Lindan

    Nicholas Lindan Advertiser Advertiser

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    The incandescent rating of a relay is often 1/5 or so of the amperage rating. The reason being that an incandescent lamp is close to a dead short when it is first turned on and it pulls a huge amount of current until it warms up. This turn-on current burns the relay contacts and can weld the contacts shut if the load is high enough.

    A relay that can switch a 12A heating load is usually rated for 200W incandescent load.

    I don't know the rating of the Patterson's relay, but if the fuse rating is 5A then I would guess they expect a 200W maximum incandescent lamp load and the relay contacts are rated at 10-12 amps.

    If you have a 300W+ lamp then you should use a remote contactor - a very heavy duty relay: http://www.mcmaster.com/#general-purpose-relays/=m4xint