Auto Verify Fire; Waterflow Zone - DSC PC4020 Installation Manual

• Short Circuit: Fire Alarm
• Open Circuit: loss of the end-of-line resistor and will be
indicated as a Zone Trouble
• Ground Fault: resistance < 40kΩ to earth ground indi-
cated as a Common Ground Fault Trouble.
Typical fire devices used on this zone type are:
• Contacts from 4-wire Smoke Detectors
• Smoke Detectors on the Addressable Loop
• WLS906 Wireless Smoke Detectors
Delayed Fire Operation
On alarm, the alarm notification outputs will activate
immediately. The transmission and event buffer log are
delayed by 30 seconds to allow the user to investigate the
cause. If the user acknowledges the alarm by pressing any
key, the alarm notification appliances will silence, the trans-
mission will be aborted and the event will not be logged to
the event buffer.
If the smoke detector is not restored to normal within 90
seconds of the alarm being acknowledged, the alarm notifi-
cation output will reactivate. The user will again have 30
seconds before the output latches and the communicator
activated. A valid access code will then be required to
silence the alarm notification appliances.

18.4 Auto Verify Fire

Auto verification is designed to reduce false alarms that
may be generated by smoke detectors. Fire alarm initiating
zones programmed as Auto Verify Fire must ONLY have
smoke detectors connected to them. The Auto-Verify fea-
ture delays the alarm response by up to 90 seconds.
All 128 zones can be programmed as Auto Verify Fire
zones. For zones on the main panel or zone expanders, this
zone is always an end-of-line resistor type with Normally
Open alarm contacts from the alarm initiating device(s).
Multiple devices may be connected on a single zone.
If the 2-wire smoke auto-verify 2-wire smoke auto-verify 2-wire smoke auto-verify feature is enabled in the 2-wire smoke auto-verify
System Toggles section (ref. # [000200]), the panel will auto-
matically verify alarms from the 2-wire smoke circuit of the
PC4701 before sounding the bells and transmitting the
alarms. See the PC4701 Installation Instructions for more
information.
The zone wiring is supervised by the control panel for:
• Short Circuit: Fire Alarm
• Open Circuit: loss of the end-of-line resistor and will be
indicated as a Zone Trouble
• Ground Fault: resistance < 40kΩ to earth ground indi-
cated as a Common Ground Fault Trouble.
NOTE: This zone type is only for smoke detectors that can
be reset by the control panel. Do not mix contact type
alarm initiating devices on zones programmed for Auto
Verify Fire. The following devices can be used:
• 2-wire smoke detectors on the PC4701 2-Wire Smoke
zone
• 4-wire smoke detectors powered from the SAUX+ output
on the PC4020 main board
• 4-wire smoke detectors powered from the AUX output
through a relay contact programmed for Sensor Reset on
the PC4204/PC4204CXCF module
• AMS-220 smoke detectors on the addressable loop
Auto Verification Operation
On an alarm from a smoke detection zone with the Auto-
verify feature selected, the panel will automatically perform
a sensor reset for 20 seconds. Upon release of the sensor
reset, 10 seconds are allowed for the smoke detectors to set-
52
tle. During this 30-second period, no alarms will be
received from any system Auto Verify Fire zone.
For 60 seconds after the 10 second settling time, if any
smoke detector in the system goes into alarm, the panel will
immediately initiate the full fire alarm sequence. If the 60-
second window expires without any smoke detector
alarms, any subsequent smoke detector alarms from Auto
Verify Fire zones will reinitiate the Auto-Verify cycle.
If at any time during the Auto-verify cycle an Alarm is
received from any other Fire zone, the auto verification
cycle will be terminated and the panel will immediately go
into the full fire alarm sequence. Once the panel is in alarm,
the Auto verification sequence will be ignored and any
alarm from an Auto-Verify zone will be transmitted imme-
diately. The auto verification sequence is only restored once
a Fire Reset has been performed.

18.5 Waterflow Zone

All 128 zones can be programmed as Waterflow Fire zones.
The PC4701 has one dedicated Waterflow zone. This type is
a Contact Input Fire Zone and is always an end-of-line
resistor type with Normally Open Alarm Contacts from the
initiating device(s). A maximum of five waterflow contacts
can be connected in parallel on a single Waterflow zone.
The zone wiring is supervised by the control panel for:
• Short Circuit: Fire Alarm
• Open Circuit: loss of the end-of-line resistor and will be
indicated as a Zone Trouble
• Ground Fault: resistance < 40kΩ to earth ground indi-
cated as a Common Ground Fault Trouble.
Typical alarm initiating devices used on this zone type are
waterflow switches for Fire Suppression sprinklers
NOTE: For this type of zone, only waterflow alarm initiat-
ing devices can be connected. A maximum of five (5) water-
flow alarm initiating devices is allowed per zone (Ref: NFPA
72 / 5-6 and 3.8.5).
Waterflow Delay
Ref #: [00020309]
This delay is to prevent false alarms due to surges in the
sprinkler system. The Waterflow delay is automatically
applied to the Waterflow zone on the PC4701. For other
waterflow zones, you must also enable the Waterflow
Delay zone attribute.
If the Waterflow Delay is required, use the PC4701 Water-
flow zones first. If delays are not required then the Water-
flow delay must be set to [000].
The Maximum delay allowed is 90 seconds. The default is
000 seconds (disabled).
Waterflow Delay restrictions:
• The Waterflow Delay must be 90 seconds or less
• Do not program the Waterflow Delay when Waterflow
switches with built-in mechanical delays are used
• In all cases, the total delay (from switches and program-
ming) must not exceed 90 seconds
• Do not use the Waterflow Delay for systems that
employ ON/OFF type sprinkler heads
The first waterflow zone to go into alarm will start the
delay timer. This timer will not restart when any subse-
quent Waterflow zones go into alarm. Once the timer has
expired and the initiating Waterflow zone or any other
Waterflow zones have not been restored, a Waterflow Fire
Alarm will be initiated.
If the Waterflow delay has been initiated, any other non-
waterflow fire zones that go into alarm before the timer