D7212 Operation & Installation Manual
Page 18
74-06913-000-B 2/96
© 1993-1996 Radionics
Power Supply
Primary Power
Terminals
1
2
Primary (AC) Power Circuit
A 16.5 VAC, 40 VA internally fused transformer (Radionics model D1640) is the primary
power source for the D7212. The AC power circuit provides 1.9 Amps of rectified AC
power. The panel reserves 500 mA of this power for internal operations leaving 1.4 Amps
for powered devices.
Transient suppressors and spark gaps protect the circuit from power surges. This
protection relies on the ground connection at terminal 10. Make sure you connect terminal
10 to a proper ground. See
Connecting Earth Ground in the Installation section.
AC Power Failure
The D7212 indicates an AC power failure when the power at terminals 1 and 2 is missing.
The
AC Fail Time program item sets the number of seconds that AC must be missing
before the panel acknowledges the failure and the number of seconds after the power
returns before the panel acknowledges the restoral of power.
You can program
AC Fail Time from 1 to 90 seconds. The Radionics default sets AC Fail
Time at 10 seconds.
Installing the Transformer
Do not short the terminals of the transformer: Shorting the terminals opens the internal
fuse causing permanent failure. Connect the transformer to terminals 1 and 2 of the panel
before plugging it into the power source.
Use 18 AWG (minimum) wire to connect the transformer to the panel. Wire length should
be kept as short as possible. Maximum length is 50 feet.
Connect the battery and then plug in the transformer: Radionics recommends that you
always connect the battery first and then plug in the transformer. Instructions for
Installing
the Battery appear on the next page.
Only plug the transformer into an unswitched, 120 VAC, 60 Hz power outlet. Secure the
transformer to the outlet with the screw provided.
Never share the transformer with other equipment: Foreign grounds on the AC input
damage the D7212 power circuit.
AC wiring can induce both noise and low level voltage into adjacent wiring. Route phone
and sensor loop wiring away from any AC conductors, including the transformer wire. Route
data wiring away from AC and phone wiring.
D8004 Transformer Enclosure required for fire systems: Use the D8004 Transformer
Enclosure for the D1640 transformer in fire and combined fire/burglary applications.
