Power Supply; Primary Power Terminals; Primary (Ac) Power Circuit; Installing The Transformer - Radionics D9412G Operation And Installation Manual

4.0

Power Supply

4.1

Primary Power Terminals

4.1.1

Primary (AC) Power Circuit

A 16.5 VAC, 40 VA internally fused transformer (Radionics model D1640) is the primary power source. 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 to connect Terminal 10 to a proper ground. See section 3.5 Connecting
Earth Ground.
AC Power Failure
The system 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 minutes or seconds that AC must be missing before the panel acknowledges
the failure and the number of minutes or seconds after the power returns before the panel acknowledges the
restoral of power. See the D9412G/D7412G Program Entry Guide for additional information regarding AC Fail
Time.
4.1.2

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 ft. (15 m).
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.
Connect the battery and then plug in the transformer: Radionics recommends that the battery always be
connected first and then the transformer be plugged in. See section 4.2.2 Installing the Battery .
Only plug the transformer into an unswitched, 120 VAC, 60 Hz power outlet. Secure the transformer to the outlet
with the screw provided.
D8004 Transformer Enclosure required for fire systems: Use the D8004 Transformer Enclosure for the D1640
transformer in fire and combined fire/burglary applications. Check with the Authority Having Jurisdiction (AHJ) on
mounting transformers on specific circuits.
4.2

Secondary Power Terminals

4.2.1

Secondary (DC) Power

A 12 V, 7 Ah (up to 14 Ah) sealed lead-acid rechargeable battery (D126) supplies secondary power for auxiliary and
alarm outputs, and powers the system during interruptions in primary (AC) power.
Lead Acid Batteries ONLY: The charging circuit is calibrated for lead-acid batteries. Do not use gel-cell or nicad
batteries.
Extra Batteries Increase Back-up Time: To increase battery back-up time, connect a second 12 V, 7 Ah battery in
parallel to the first battery to form a 12 V, 14 Ah battery. Use a D122 Dual Battery Harness to ensure proper and
safe connection.
D1218 Battery
The D1218 is a 12 V, 17.2 or 18 Ah battery and can be used in applications requiring extended battery standby time.
Up to two D1218 batteries may be connected when used with a D122 Dual Battery Harness. Do not use any
additional batteries when using a D1218 battery.
4.2.2

Installing the Battery

Place the battery upright in the base of the enclosure. Locate the red and black leads supplied in the literature
pack. Connect the black battery lead to Terminal 4, and then to the negative (-) side of the battery. Connect the red
© 2002 Radionics
D9412G/D7412G Operation & Installation Guide
Page 25
D9412G/D7412G
Power Supply
43488D