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SENSOR REPLACEMENT
This mode inhibits all controller outputs to allow
replacement of the sensing element without removing
power from the controller. In addition, this mode
automatically sets the factory default values for
sensor calibration. Alarm setpoints and calibration
gas concentration are not affected.
CAUTION
Upon entering the Sensor Replacement mode, all
previously entered sensor calibration information
is lost. Sensor calibration must be performed,
even if the sensing element was not replaced.
To enter the Sensor Replacement mode, either enter
the Calibrate mode as described above and press the
SET button, or hold the RESET button for 7 seconds
while in the power-up time delay. To exit this mode,
press the RESET button. Upon exiting the Sensor
Replacement mode, the controller returns to normal
operation after a time delay (five minutes or as soon
as no alarm setpoints are exceeded).
SETPOINT ADJUST
The Setpoint Adjust mode is entered by depressing
the SET button for approximately one second. In this
mode the alarm setpoints and calibration gas level
are sequentially displayed on the digital display for
approximately five seconds and the corresponding
LED flashes. To change the setpoint, depress the
RESET button to increase the displayed value or the
SET button to decrease the value. If no changes
are made for 5 seconds, the microprocessor
automatically advances to the next setpoint. At
the end of the sequence, the microprocessor
automatically returns to the Normal operating mode.
DC CURRENT OUTPUT CALIBRATION
This mode is used to calibrate the 4 to 20 ma dc
output. To enter this mode, hold the SET button,
then press RESET. First the 0 ppm value (4 ma) is
generated for approximately 7 seconds while the
Low LED flashes. Then the full scale value (20 ma)
is generated while the High LED flashes. Finally the
current output level during calibration is generated
while the CAL LED flashes. The microprocessor
automatically returns to the normal operating mode
at the end of the sequence. Adjustments to the
current output level are made by pressing the RESET
(increase) or SET (decrease) button. This procedure
requires a dc current meter to monitor the actual
controller dc milliampere output.
2.1
Section II
System Installation
INSTALLATION
The C7064E Sensor is not included in the FMRC
approval.
Refer to the sensor manual for complete
information regarding sensor installation.
SENSOR LOCATION
Proper location of the sensor is essential for providing
maximum protection. The formula for determining
the most effective number and placement of sensors
varies depending on the conditions at the job site.
The individual performing the installation must rely
on experience and common sense to determine
the number of sensors needed and the best sensor
locations to adequately protect the area.
The following factors are important and should be
considered for every installation:
1. Since hydrogen sulfi de is heavier than air, it will
normally tend to settle near the fl oor or ground,
unless it is heated, mixed with other gases that
are lighter than air, or prevented from doing so by
air movement.
2. How rapidly will the H
Select a location for the sensor as close as practi-
cal to an anticipated source.
3. Ventilation characteristics of the immediate area
must also be considered. Air movement will
cause the gas to accumulate more heavily in one
area than another. Sensors should be placed
where the most concentrated accumulation of
hydrogen sulfi de gas is anticipated. Also con-
sider the fact that some ventilation systems do not
operate continuously.
4. The sensor should be located where it is safe from
potential sources of contamination.
5. The sensor should be pointed down to prevent
the buildup of contaminants on the fi lter.
6. The sensor must be accessible for testing and
calibration.
9
NOTE
NOTE
S gas diffuse into the air?
2
95-8401
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