to heat build-up and is much happier with an external way to
dissipate some heat, as I’ve discussed several times.
12. It’s OK to run DC and DCC at the
same time
Another topic suggested by Mark Gurries.
I’m sure the source of this myth is folks who are trying to
ease the transition to DCC. Over the years, I’ve seen many
ideas of how to mix the two technologies on a single layout at
the same time.
If you want to go this way, wire your layout with DCC in mind
(large gauge bus wires and frequent feeders). If you design in
some block switches, make sure they are heavy-duty automo-
tive type (rated 10 amps or more), not micro-miniature toggles.
Don’t use any DCC-only accessories, like reverse loop controllers.
Then, use a connector between your DCC system and the layout.
I currently use a two-pin con-
nector from Molex that is rug-
ged, reliable and inexpensive;
previously, I used Cinch-Jones
connectors. That way, you can
unplug your DCC system and
plug in a DC power pack and
run the layout on DC, if you
want to do so.
The danger of simultaneous
running is the possibility of
interconnection between the
two technologies, even when
they are on separate tracks.
If a loco jumps the track and bridges to a parallel track that is
being used with different technology, the resulting intercon-
nection can seriously damage the DCC system, any decoders on
either part of the layout, and even the power pack supplying
DC to the layout.
Schemes that use block selection switches to accomplish the
transition had best be protected, as we did for a bit on the
Flagstaff (AZ) club. There was a box with a two-direction (center
off) switch that provided AC power to the DCC system or the DC
power packs.
Thus there was no way that
both systems could be active
at the same time unless
someone bypassed the switch
and plugged one system
directly into the wall.
Conclusion
So there you are, a dozen
dragons slain. Hopefully, I
explained the “why” behind
the “what” well enough
that you don’t have to take
my contentions purely on
face value. If you found this
“The only safe way to run DC and DCC on
the same layout is not at the same time.
Completely disconnect one before you
connect the other.”
MRH-Mar 2014
