2018KCL(ip) SERIES SIGNAL MONITOR
OPERATIONS MANUAL
Eberle Design Inc.
Page 5
illuminating the CLEARANCE indicator, transferring the Output relay contacts to the fault
position and enabling the Stop-Time output to the controller.
Minimum Yellow Plus Red Clearance monitoring is enabled on a per channel basis using
the Minimum Yellow Plus Red Clearance Enable programming in the Datakey (see section
4.2.7.2) and requires the controller cabinet assembly to be adapted for Red Signal
Monitoring. Minimum Yellow Plus Red Clearance monitoring is disabled for all channels
when the Red Enable input is not active or the pin#EE input (MC Coil) is active.
2.4.2.1 MINIMUM YELLOW PLUS RED CLEARANCE DISABLE
The
MUTCD Section 4D.10 Yellow Change and Red Clearance Intervals
requirement
states, “A yellow signal indication shall be displayed following every CIRCULAR GREEN or
GREEN ARROW signal indication”. In some legacy intersection cases this requirement is
not met due to the lack of a Yellow signal head on an overlap phase (channel), and signal
timing that precludes what would normally be the overlap clearance interval. In this case
the Minimum Yellow Plus Red Clearance monitoring function can be disabled for that
channel. It should be noted that the Minimum Yellow Plus Red Clearance monitoring
function is only intended to be disabled under these special conditions.
2.5 AC LINE BROWN-OUT DETECTION
When the AC Line voltage is below the "drop-out" level the 2018KCL will suspend all fault
monitoring functions, transfer the Output relay contacts to the fault position, and enable the
Stop-Time output to the controller. The AC PWR indicator on the front panel will flash at a
rate of 2Hz to indicate the brown-out status. When the AC Line voltage returns above the
"restore" level the monitor will resume normal operation and the AC PWR indicator on the
front panel will remain illuminated.
The AC Brownout dropout and restore voltage levels are selected by the 92Vrms Brownout
option in the Datakey. See section 4.2.3.14.
AC Line Brown-out Detection is provided to prevent a dark intersection in the event a
brown-out causes the cabinet controller to release control of the intersection. If this occurs
and the intersection is not placed into flash, the monitor will detect a Red Failure (absence
of signal) or WDT and will require a manual reset.
The "low AC Line Voltage" level on
the Controller Unit should be set at least 5 volts below the monitor drop-out level.
2.5.1 MINIMUM FLASH TIME
A Minimum Flash time option can be selected (see section 4.2.3.1.1) which provides a flash
interval of at least 4 seconds and at most 16 seconds in duration following a power-up, an
AC Line interruption, or a brownout restore. During this interval the unit will suspend all fault
monitoring functions and transfer the Output relay contacts to the fault position. The AC
PWR indicator on the front panel will flash at a rate of 4Hz.
The minimum flash interval will be terminated after the selected minimum flash time value if
the Watchdog input has made five transitions between the True and False state and the AC
Line voltage is greater than the restore level.
2.6 LEDGUARD
®
LED FIELD SIGNAL SENSING
The Signal Monitor can be configured to use a technique called
LEDguard
®
that is designed
to better monitor the characteristics of LED based signal loads. Each field signal input is
measured and compared to both a high threshold and a low threshold value to determine
On / Off status. This differs from conventional operation where the active threshold is
picked according to the color of the field signal. Once the high and low On / Off thresholds
(Section 8.1.2) have been determined using the input RMS voltage, the individual fault
monitor functions use the appropriate threshold to determine if a fault condition exists.