Carbon Monoxide Alarm User Manual

Page 34
entered and the instrument must be re-calibrated
before being put back into service.
To re-initialize the PhD
2
:
(1) Enter the Diagnostics Test mode by turning the
detector on while simultaneously holding down the
"+" and "-" buttons. The "Diagnostic Test" screen will
briefly appear.
This screen will be followed by another which shows the
release date of the software version currently installed in
the PhD
2
, and the instrument identification number.
(2) Press the "Cal" button within three seconds to begin
the re-initialization sequence.
(3) The Re-Initialization Set-up screen will briefly be
displayed. This will be followed by the Initialization
Adjust message.
(4) Press the "Cal" button to re-initialize the detector. A
screen will indicate that re-initialization is in progress.
This screen will be followed by another indicating
successful completion. The PhD
2
will then turn itself
off.
Remember to verify that sensor choices, alarm
settings, datalogging interval and other configuration
choices are correct. The PhD
2
must be recalibrated
before being returned to service.
(5) Pressing the MODE button cancels the re-
initialization procedure, and returns the instrument to
the Diagnostic Mode screen showing LEL and
oxygen diagnostic counts.
7.2.3 Specific problems
7.2.3.1 Unit will not turn on
Possible causes:
Battery discharged, microprocessor / software
malfunction.
Solution(s):
Take the instrument to a non-hazardous location. Plug
the PhD
2
into the battery charger for several minutes.
With the instrument still connected to the battery charger,
attempt to turn the detector on. If this works, the battery
needs to be recharged or replaced. If the instrument still
fails to turn on, re-boot the microprocessor using the
procedures discussed in Section 7.2.1. If the instrument
still fails to turn on, return to factory for repair.
7.2.3.2 Problem: Unit will not turn off
Possible causes:
Software malfunction, low or bad battery, faulty on / off
mode switch.
Solution(s):
Hold MODE button down for thirty seconds. This should
turn the instrument off. Take the instrument to a non-
hazardous location. Plug the PhD
2
into the battery
charger for several minutes. With the instrument still
connected to the battery charger, attempt to turn the
detector on. If this works, the battery needs to be
recharged or replaced. If the instrument still fails to turn
on, re-boot the microprocessor using the procedures
discussed in Section 7.2.1. If the instrument still fails to
turn on, return to factory for repair.
7.2.3.3 Problem: LEL sensor readings
unstable
Possible causes:
Loose connection, bad sensor, improper calibration.
Solution(s):
Check sensor output in Diagnostics Test mode; value
should be within 200-275 counts. Re-calibrate. Replace
the LEL sensor if necessary.
7.2.3.4. Problem: Toxic sensor readings
unstable or numbers flash instead of
remaining steady
Possible causes:
Loose connection, bad sensor, improper calibration, or
sensor saturated by exposure to excessively high
concentrations of gas.
Solution(s):
Check that the sensor is firmly in place. Tighten sensor
connections. Check sensor in Diagnostics Test mode;