Installing A Power Supply; Connecting Ac Power And Earth Ground To The Control Unit - ADT FOCUS 200 PLUS Installation And Setup Manual

Installing a Power Supply

If you have determined that the control unit's power supply will not handle the current draw or that
the voltage drops along the RS-485 bus are too large, then add 472372 Power Supply Module. The
supplementary power supply can be added to any section of the RS-485 bus by connecting it directly to
the bus or connecting it via a gateway. The power supply and standby batteries are housed in a 472381
Power Unit Housing along with a supervisory SIM or PID.
The power supply receives 16VAC from an input transformer. Leave the communication wires (yellow
and blue) and the power common ground wire (black) connected to the bus terminals of the gateway
and continue on to the next device on the cable run (if necessary).
To install the power supply, perform the following steps:
Step
1
2
3
4

Connecting AC Power and Earth Ground to the Control Unit

•
Make sure POWER switch (on control unit circuit board) is in the OFF position before connecting AC
power to terminals 1 and 2.
•
Make sure the circuit breaker that controls the circuit providing power to the control unit is in the OFF
position.
The 120VAC circuit that the transformer is connected to should be dedicated to powering the control
unit, should provide power continuously for 24 hours, and should not be controlled by a wall switch.
Any inadvertent shorting of the secondary leads of the 50VA transformer will cause a fusible link in the
secondary winding to open, and render the transformer useless.
Connecting the Transformer
To connect the transformer to the control unit, perform the following steps:
Step
1
2
Action
Cut the + 12V (red) wire of the incoming RS-485 bus, and insulate the end of this wire so
it will not short to any other component in the system.
Connect the + 12V output of the power supply to Terminals 1 (common ground) and 2 (+
12V) of the gateway and continue to the next device on the RS-485 bus (if necessary).
Note: Use terminal 1 to connect the two incoming common ground wires (one from the
incoming bus and one from the power supply) and to connect an outgoing common
ground wire.
Connect the supervisory contacts of the power supply to the monitoring terminals of a
SIM (or PID) to provide supervision of the + 12V power.
Note: The power supply will provide power to the remaining section of the quad trunk
and also float-charge its standby battery.
Assemble the power supply according to the instructions accompanying the power
supply.
Action
Make sure the power switch on the control unit is in the OFF position.
Identify the circuit breaker or fuse that controls the branch circuit, furnishing power to
the control unit. Make sure it is in the OFF position. Use a 326670(2667) AC Power
Switch Shielding Kit to protect the circuit breaker switch from inadvertent operation.
Where fuses are used, mark the fuse label to indicate that it must not be removed except
for replacement purposes.
Section 12 – Power Requirements
12-15