Purpose of diodes in new Alltrax SR diagram?

[Goliath]

Just downloaded a new copy of the SR manual, and they added several new wiring diagrams. The one I'm using is the Generic Series with SW202 Reverse.
There's a few diodes I've not seen in other diagrams, and was wondering if they're really necessary, or beneficial.

I've attached a copy, with markup.
Opinions welcome!

[Sergio]

If You are using a SPDT switch to control both the Reversing Contactor and the KSI Controller power, then the diodes are required to keep the Forward and Reverse Solenoid coils isolated from each other.

The alternative is to use a DPDT switch where one pole controls which Reversing Contactor coil gets power and the other pole simply interrupts the KSI power when the switch is in Neutral.

[Sir Nuke]

For what I remember, those diodes are part of the actual F&R switch, they aren't an additional diode.

but I'm sure that someone like JohnnieB will see this and chime it to set the record straight.

[JohnnieB]

As Sergio mentioned, without the steering diodes you'd have both coils of the reversing contactor energized and the half speed reverse activated at the same time with either F or R selected on the F/R switch.

Also looks like Alltrax needs to go back to the drawing board. They have a nonexistent switch in the main solenoid activation circuit. The "run-switch" between keyswitch and fuse does not exist if the original F/R assemble that the reversing contactor replaces was removed.

Personally, I would wire the new On-Off-On switch in after the foot switch and eliminate the need of steering diodes.

[scottyb]

Originally Posted by JohnnieB

As Sergio mentioned, without the steering diodes you'd have both coils of the reversing contactor energized and the half speed reverse activated at the same time with either F or R selected on the F/R switch.

Also looks like Alltrax need to go back to the drawing board. They have a nonexistent switch in the main solenoid activation circuit. The "run-switch" between keyswitch and fuse does not exist if the original F/R assemble that the reversing contactor replace was removed.

Personally, I would wire the new On-Off-On switch in after the foot switch and eliminate the need of steering diodes.

another published rough draft

[JohnnieB]

Also, where is the reverse beeper.

A good ambulance chaser might find that oversight interesting.

[scottyb]

I shared my conversion diagram with Alltrax tech this AM complete with foot switch and rev beeper. Because we have been routing current differently than what they show and I wanted their feedback, as usual.

[Threeput]

Normally a diode across a DC coil is to discharge the induced current set up by the collapsing magnetic field when the coil is switched off...the diode is wired in reverse of the polarity of the coil main connections...as the direction of the collapsing field current.. is in reverse of the current going thru the solenoid when activated...Lenzs Law
So when Solenoid is pulled up..current flow is blocked going thru the diode..
also as mentioned diodes are also used for blocking in a DC circuit