pcmeiners
Well-known member
Made modification to control my QR 325. Added one dual time delay relay to lock out the power contactor should the compressor run continuously for more the a specified amount of time, so at the moment ,if it runs continuously for more then 1 1/2 hours it shuts down, and locks out until a manual reset, via a latching relay. Each time the compressor powers on by the tank switch it reset the timer .
Second modification involves an added oil pressure switch. The oil switch is a single pole double throw Nason pressure switch, one contact is in the power circuit to the contactor, the other pole goes to a latching relay circuit. . Should the oil pressure drop below 13 lbs, the compressor will lock out until a manual reset. Issue with this circuit I needed to add a time delay of a few seconds, to maintain a circuit as the power is turned on, and the oil pressure builds to >13lbs, or the latching circuit would kick in immediately. Other issues with the circuitry involved reverse flow of power in the circuits, messing up the logic. Next time I do something like this I will give a programmable logic controller a shot, this required too much wiring and space, even though it requires few brain cells to maintain (my main goal). All circuitry is 12vdc, except for the contactor coil which is 240AC
Third part of the circuit involved a dual time delay relay (dpdt) to activate a 12vdc solenoid valve to drain the tank, was $22 total for the valve and delay relay. Added a screen filter before the solenoid valve, and a 1/2" diameter magnesium anode in the same area.
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Have to plug the relays, cheap and versatile....
http://www.ebay.com/itm/0-1s-99h-Pr...717543?hash=item2ca92ad4e7:g:xZUAAOSwMtxXwSvD
http://www.ebay.com/itm/DC-12V-0-30...466259?hash=item1a1b239453:g:3DAAAOSwhdRYWnnN
Second modification involves an added oil pressure switch. The oil switch is a single pole double throw Nason pressure switch, one contact is in the power circuit to the contactor, the other pole goes to a latching relay circuit. . Should the oil pressure drop below 13 lbs, the compressor will lock out until a manual reset. Issue with this circuit I needed to add a time delay of a few seconds, to maintain a circuit as the power is turned on, and the oil pressure builds to >13lbs, or the latching circuit would kick in immediately. Other issues with the circuitry involved reverse flow of power in the circuits, messing up the logic. Next time I do something like this I will give a programmable logic controller a shot, this required too much wiring and space, even though it requires few brain cells to maintain (my main goal). All circuitry is 12vdc, except for the contactor coil which is 240AC
Third part of the circuit involved a dual time delay relay (dpdt) to activate a 12vdc solenoid valve to drain the tank, was $22 total for the valve and delay relay. Added a screen filter before the solenoid valve, and a 1/2" diameter magnesium anode in the same area.
[
Have to plug the relays, cheap and versatile....
http://www.ebay.com/itm/0-1s-99h-Pr...717543?hash=item2ca92ad4e7:g:xZUAAOSwMtxXwSvD
http://www.ebay.com/itm/DC-12V-0-30...466259?hash=item1a1b239453:g:3DAAAOSwhdRYWnnN
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