95-8723
4
3.5
NOTE
The output of the 0 to 20 mA current loop
is monitored by the fault detection circuitry
of the U5015. Therefore, an open circuit on
the loop will cause the fault relay to change
state.
An alarm will normally override a fault, unless
the nature of the fault impairs the ability of
the detector to generate or maintain an alarm
output (i.e., loss of operating power).
INTEGRAL WIRING COMPARTMENT
All external wiring to the device is connected
within the integral junction box. The detector is
furnished with a maximum of four conduit entries,
with either 3/4 inch NPT or M25 threads.
LED
An LED, located on the detector (see Figure 1),
indicates normal operation and notifies personnel
of an alarm. Table 2 indicates the condition of the
LED for each status.
LATCHING
A detector configured for latching operation will
remain in an alarm state indefinitely, after an
alarm occurs.
NON-LATCHING
A detector configured for non-latching operation
will check the alarm status of the detector once
every 10 seconds. Once smoke falls below the
alarm threshold, the alarm annunciation will clear
within 10 seconds.
IMPORTANT
The latching or non-latching configuration
must be specified during order placement.
It is
not
field configurable.
Only the alarm annunciation can be
configured for latching operation.
CONTINUOUS SELF-TEST
During normal operation, the detector performs
the Self-Test function automatically in the
background once per second. During the test,
detection is not interrupted and no indication is
given if the test passed. If the test fails, a critical
fault will occur. If degradation is present and
approaching critical levels, an advisory fault will
occur.
MANUAL SELF-TEST
The Manual Self-Test function will immediately
check the smoke chamber optics for degradation.
Once initiated, there will be a one second delay
before the result of the check is active. If there is
a failure, the LED will shut off immediately after
the one second test and a critical fault will occur.
If the test passes, an alarm will be annunciated
while the LED remains active.
For a latching detector, the alarm will continue
until power is cycled to the unit. For a non-latching
detector the alarm will clear after 10 seconds. If
the test passes, but there is degradation present
and approaching critical levels, an advisory fault
will occur.
Magnetic Switch
The magnetic switch is used to initiate the Manual
Self-Test (see Figure 3). Apply the magnet to the
exterior housing and the LED will light to indicate
that the magnet is detected. The LED will remain
lit for at least one second during the test. After
the initial delay, the test status will be indicated as
described in the "Manual Self-Test" section.
Table 2—Detector Status Indicator
Detector Status
LED Indicator
Power On /
Normal Operation
Steady Off
1 blink on every 4 seconds
Alarm
Steady On
Figure 3—Location of Magnetic Switch