Bell Output Wiring (Bell And Bell ); Earth Ground Wiring; Applying Power (Ac And Battery) - DSC PC4020 Installation Manual

2.12 Bell Output Wiring (BELL
These terminals are used for powering
bells, sirens or other devices requiring
steady output voltage on alarm. The
panel can provide up to 2A short-term
or 700mA long-term current. The out-
put is supervised. A trouble condition
will be generated when the bell con-
nection is lost. If no bell or siren is
being used, connect a 1000Ω resistor
across the BELL+ and BELL- terminals
to eliminate a trouble condition.
To ensure proper operation, the wire length of the bell loop
must be considered.
Consult the following chart to determine the maximum
wire length for the bell loop with respect to current. The
values reflect the use of a 30 watt siren.
Distance to last bell/siren (ft/m)
Bell Loop
22 AWG 20 AWG
Load
Wire Wire
Current
2000mA 18/6 29/9
1800mA 20/6 32/10
1000mA 36/11 58/17
700mA 52/16 82/25
500mA 73/22 115/35
100mA 364/110 577/175 922/279 1467/445
To increase the length, double up on wire. For example,
when using 22-gauge quad, use two conductors for the
Bell+ connection and two for the Bell-. This effectively dou-
bles the maximum distance.
For UL residential installations, when a bell or siren is used
for fire signaling with a pulsed cadence, it must be con-
nected between the AUX+ and BELL- terminals. To main-
tain bell circuit supervision, do not connect more than one
device to the BELL- terminal. A fire bell or siren used for
this application must be UL Listed and have a current con-
sumption of 400mA or less (e.g. Wheelock MT-12/24-R).
NOTE: For Commercial Fire applications, you must use the
'CF' version of the panel and the PC4702BP.

2.13 Earth Ground Wiring

The cabinet should be earth grounded using the grounding
kit supplied. Ensure that the connection from the cabinet to
the metallic cold water pipe or earth grounding rod is made
with minimum 14-gauge solid copper wire.
The EGND terminal must be connected to earth ground to
enable ground fault detection. A Ground Fault trouble will
be indicated if any conductor on the system has a resistance
to earth ground of 40kΩ or less.
and BELL )
+ -
18 AWG 16 AWG 14 AWG
Wire Wire Wire
46/14 73/22 116/35
51/16 81/25 129/39
92/28 147/44 233/70
132/40 210/64 332/101
184/56 293/89 465/141
2326/705
I n s t a l l a t i o n
Only earth ground the main panel and the first module
connected to the telephone line.
Tighten nut to break paint and make
good connection to the cabinet

2.14 Applying Power (AC and Battery)

WARNING:: Do not connect the battery or transformer
until all other wiring is complete.
Battery Connection – Red & Black Battery Leads
Connect the red battery lead to the positive terminal of the
battery and the black lead to the negative terminal.
WARNING:: Observe the correct polarity. If the battery is
connected backwards, the panel will not operate.
AC Power Terminals
WARNING:: Connect the battery before connecting the AC.
A 16V, 40 VA transformer connected to an unswitched AC
power source should be wired to these terminals.
To achieve the rated outputs as previously described, the
AC input must be connected to the secondary of a trans-
former rated at 16 VAC, 40VA minimum. The transformer is
not supplied with the equipment and must be mounted out-
side the cabinet. Do not connect the transformer primary to
an outlet that is controlled by a switch.
The control panel monitors the presence of AC. Upon the
loss of AC power a trouble condition will be generated. The
keypad trouble light will turn on. If programmed, the key-
pad will also beep. For more information regarding AC
options, see 10.1 'AC/DC Power Options'.
Applying Power to the Main Panel
Once all field wiring has been completed and checked for
opens, shorts and grounds, power can be applied to the
panel as follows:
1. Connect the battery leads.
2. Connect the AC transformer.
The panel will not power up correctly if AC power is
applied before the battery is connected.
Battery Selection Charts
The charts below are to determine the battery required to
support the main panel for either 24 hours or 60 hours in
the standby mode. The battery size is measured in amp
hours (Ah). To determine the appropriate battery size, per-
form the following:
1. Calculate the total current required when the panel is
not in alarm. This is the standby current. See section 2.4
for further information on current calculation.
2. Determine the current that will be drawn when the
panel is in alarm.
a n d W i r i n g
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