Carbon Monoxide Alarm User Manual

Page 14
the PhD
2
case. Over tightening may lead to the
battery pack being damaged.
Figure 2.1: PhD
2
showing removable NiCad battery
pack
2.3.1.2 Sealed lead-acid
The PhD
2
may also be equipped with an internally
housed, sealed lead-acid rechargeable battery.
Removal or replacement of the sealed lead-acid battery
requires disassembly of the instrument case.
The sealed lead acid battery may
not be removed or replaced while the PhD
2
is being
used or located in a hazardous location.
CAUTION: Removal of the sealed lead acid battery
will result in the immediate loss of recorded gas
measurement data. Recorded gas measurement data
should be downloaded before disconnection of the
sealed lead acid battery.
(Calibration and configuration data are stored in a
non-volatile permanent memory, and are not subject
to loss due to battery removal.)
2.3.2 Battery life
Allow the PhD
2
to operate two to three minutes before
checking battery voltage. A reading of 6.4 volts or higher
indicates the battery is sufficiently charged for use. A
fully charged PhD
2
battery should allow for eight hours of
continuous operation.
If the expected duration is not being received, try "cycling"
the battery by turning it on for a few hours every day then
recharging. If this procedure fails to improve
performance, the battery will probably need to be
replaced.
To ensure the best performance, the PhD
2
should be
kept on the battery charger continuously whenever
the instrument is not being used. The battery cannot
be damaged by overcharging with the Biosystems
charger.
2.3.3 Low battery voltage alarms
When the battery voltage is reduced to 5.65 volts, an
audible alarm sounds, and the display screen indicates a
low battery condition exists. It is best to leave any
hazardous area in which the instrument is being used as
soon as possible after a low battery alarm has been
sounded.
At this stage, the low battery alarms may be silenced for
a fifteen minute period by pressing the large black mode
push-button. The alarm will continue to sound every
fifteen minutes until the voltage reaches 5.55 Volts.
When the battery voltage is reduced to 5.55 Volts, the
battery alarm will sound every 30 seconds. At this point it
is no longer safe to continue to use the instrument until
the battery has been recharged. It is necessary to leave
any hazardous area in which the instrument is being used
immediately.
When the battery voltage is reduced to 5.45 volts, the
PhD
2
automatically shuts off, protecting the battery from
deep discharge.
2.3.4 Charging procedures
The PhD
2
should be kept continuously on the charger
at all times when not in use.
CAUTION: Batteries may only be charged with the
Biosystems PhD
2
battery charger. Use of any other
charger may result in damage to the instrument and
voids the standard Biosystems warranty.
(1) Check that the instrument is turned off. (If it is not,
press the MODE button until the message "Release
button" appears on the screen).
(2) Connect the charger to the dual-purpose battery
charger / RS 232 connector port on the right hand
side of the PhD
2
.
Figure 2.2: Side view of PhD
2
showing the battery
charger / RS 232 connector