BAC Forum
General Boards => Technical Support => Topic started by: Harold and Gloria Skipworth on December 16, 2014, 01:24:30 AM
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I always wondered why diodes were used in the wiring for the slide outs. After tracing out the wire it became apparent that with all eight switches being able to start the pump some means of isolation was needed to allow a switch to only activate it's intended solenoid and the pump. The attached sketch is my attempt to illustrate what I believe is buried within the walls and floors.
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Harold,
I can't quite follow your diagram, but in most cases when a DC motor or something with a winding like a solenoid is involved which is powered using switch contacts, it is customary to protect the contacts from arcing with diodes. When the switch is opened the field in the motor collapses making it generate voltage in the opposing polarity. The diodes are wired so they short that current to ground reducing or eliminating the arcing in the switch. Not sure if that is the whole story here but it looks like it.
Later Ed
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I don't doubt the idea of using the diodes as a protection from arcing. As I can only access the wiring behind the switches in the bedroom wall , I can only attest to that section of the sketch showing the switches and how the diodes are connected. The rest of the diagram is what makes sense to me . Regrettably I can no longer crawl under the rig far enough to confirm the wiring at the pump and manifold . If what I represent is accurate the diodes would indeed stop a spike generated by the pump when shutdown. They would no effect on the individual solenoids though. if the pump is fed by a relay or solenoid switch would a spike even reach the wall switch?