14
Connect Accessory Transformer to Relay Power Terminals
Y
our BPC2 requires an external power source to operate its 8 internal relays. This must be
supplied from a separate accessory transformer. Connect an accessory transformer with
an 12-14 VAC output to the BPC2’s front screw terminal connections marked “A” and “U” as
shown in Figure 9 below. If your installation includes more than one BPC2, they can share the
same accessory transformer as long as it combined the current draw of the relays and does not
exceed the capacity of the accessory transformer (See Specifications, Electrical at the end of
this document).
Figure 9. Connecting two BPC2 modules with LCS PDI cables and parallel external relay
power.
The BPC2 relays switch on and off the power to connected track power blocks. However, the
BPC2 does not supply the operating power required by your locomotives or any other device
drawing power from the track. That is the job of the Track Power transformer (not included).
Proper connection of Track Power transformers to a BPC2 is described later in this manual.
To connect the Relay Power Terminals on your BPC2:
1. Attach one wire to the Common/Ground/U terminal of your transformer and connect it to
the POWER U terminal on the BPC2 unit. Do not connect this terminal to the outside rail.
2. Attach another wire to the Power/A terminal of your transformer and connect it to the
POWER A terminal on the BPC2 unit.
3. If your layout includes additional BPC2 or ASC2 devices, you can use the spare A and U
terminals on the first unit to jumper power to your next BPC2 device as shown in Figure 9.
LCS PDI CABLES
use either connector
AC Power
PROGRAM
A U A
U
BPC2
BLOCK
BLOCK
COMM
COMM
8
7
6
5
4
3
2
1
6-81640
LCS PDI CABLES
use either connector
AC Power
PROGRAM
A U A
U
BPC2
BLOCK
BLOCK
COMM
COMM
8
7
6
5
4
3
2
1
6-81640
Accessory
Transformer
12-14VAC
A
U
Configuring Your BPC2