Electrofog points and DCC wiring

[Noel]

Electrofrog point vastly improve the low speed running of locos over point work avoiding stalling or juddering. This is especially useful for locos that do not have all wheel all axle power pic ups or 060 and 040 steam locos, or diesels with power pickups on only one bogie  or 060, 040 shunters.  Its fair to say that most modern locos with all wheel pick up on all axles and bogies especially if they have keep-a-live capability will run ok over insulfrog points which do not need any wiring at all. Older locos did not have AWP so did not run smoothly over insulfrog points at low speeds, especially 4-4-0 0-4-0 and 0-6-0 locos. Nowadays more and more folks put up with the little bit extra work to install electrofrog points on their layouts for smooth running. This applies to DC or DD.

Electrofrog prints require some basic additional wiring to manage and switch frog polarity when the point is thrown. The following alterations below are recommended for each point before track laying to facilitate trouble free frog polarity switching (DC or DCC) without risk of short circuits: (these are documented on Peco instructions). 

STEP 1

Insulate point frogs using plastic fish plates (ie both frog rails). The dropper wires from each point can double up for frog switching and also DCC bus power.

Recommend dry pin track before laying to get all the wiring holes through the baseboard sorted and drill point motor access holes. Track can be tested at this stage for continuity. Later track bed can be put in place and track temporarily pinned onto track bed before being glued to the track bed by means of PVA ballasting method (ie ballasts track as well as glues it to base). Later the temporary track pins can be removed for better aesthetics.

If using modular baseboard construction the baseboards can temporarily be sat on their edges so for wiring (ie using the back scene boards to old them vertical). This is so much easier than crawling and working under as baseboard. Makes fitting of point motors and wiring much easier. In the example below the length and amount of wiring needed to each point is greatly minimised by using point motors with built in frog switches (ie the three wires in step one above only need a short run to the point motors switch terminals, so no long cable runs back to a spaghetti control box at the other end of the layout.

In the example below analog stall point motors were used (eg Cobalt or Tortoise) which have built in switches for frog switching LEDs, etc. Below there is an 8 way DCC accessory decoder board connected to each Cobolt analog point motor with only two wires per motor. This eliminates the need to run wires from each point all the way back to a central control box on the layout, and means only short local wire runs to the nearest accessory decoder. Had I used Digital Cobalt Decoders even less wiring would have been needed as the point motors would not need the accessory board and could have got their power from the overhead track via the droppers.

This allows points to be DCC switched as accessories on a DCC cab controller, BUT if a DCC switch encoder board is used points can also simultaneously be switched by physical switches or point levers and the remote switch box only needs to be connected to the DCC bus using two wires, instead of the old mess of running three wires form each point to a remote switch or lever all the way across and underneath a layout.

Best of both worlds, DCC cab accessory switching or manual lever switches.

Pair of Blue and yellow wires below connect each point motor to the accessory decoder board.

It is a real help if baseboard can be put on their sides for wiring one at a time. They can be daisy chained together using old computer 25pin D type connectors.

DCC encoders can be used to facilitate simplified wiring of switches for point motors. Only two wires needed to connect a remote bank of switches or point levers anywhere on the layout. These can be plugged into most systems DCC cab bus. (eg portable virtual signal boxes).

For the physical installation of point motors testing alignment of screw hols and lever hole a 9v batter with a switch allows a single point motor to be operated and tested without any other wiring having been done. This is handy to drill screw holes correctly and test the throw of the point motor. Its a few seconds to move this test harness from one point motor to another.

Have fun. Compared to the brillo pad and maze of wiring I used to have to lay under the DC layout 20 years ago this is 1/4 of the work and wiring needed.