DCS / POLARITY Switch
Your model is equipped with a DCS / POLARTY switch that is used to properly orient the
polarity of the power and the DCS signal going to the circuit board.
The DCS / Polarity Switch is located underneath the engine, between the truck and fuel
tank.
There are 2 situation that may require the operator to change the position the DCS /
Polarity Switch.
DC Mode
In DC operation the polarity of the voltage applied to the track rails determines the
direction of travel for the engine. If the MTH engine is facing the same direction as other
engine(s), but it runs in the opposite direction of the other engine(s) when the power is
applied to the track, you will need to select the other position of the DCS Polarity Switch.
This will change the direction of travel for the MTH RailKing Gauge-One Engine and
will have the MTH engine operating in the same direction as the other engine(s).
DCS Mode
In the DCS mode (using AC or DC). The control electronics is expecting the DCS signal
on the high or + side of the transformer / power pack output. If the engine is placed on the
track facing the wrong direction, the engine will not receive the DCS Signal and will not
be recognized by the Track interface unit (TIU). If the engine is not recognized by the
TIU, or if the engine sounds start up when the power is applied to the track with a TIU
connected, the DCS / Polarity Switch will need to be moved to the other position.
The DCS / Polarity Switch is oriented so that the switch is moved toward the rail with
High / + / Red output terminal from the Transformer / Powerpack / TIU.
If your engine starts out in the direction you want or if the TIU recognizes the engine
there is no need to change the setting of the DCS / Polarity Switch.
Narrow Nose Dash-8 Diesel Locomotoive
10
DCS Polarity Switch
Figure 11
