Honeywell XNX, Technical Manual

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XNX Universal Transmitter
Introduction 6
• When the transmitter is equipped with the optional Remote Mount Kit,
the remote sensor must be securely mounted in a fixed position. The
Remote Sensor kit is not intended to be used as a hand-held sensor.
• Enclosures of remotely mounted sensors contain aluminum. Be careful
to avoid ignition hazards due to impact or friction when installed in
Zone 1 locations.
• Install the junction box according to local codes and manufacturer’s
requirements.
• The enclosures of remotely mounted 705HT sensors contain
aluminum. Be careful to avoid ignition hazards due to impact or friction
when installed in Zone 1 locations.
• Power off the transmitter before changing S3 or S4. Both switches
must be set in either Source or Sink prior to applying power.
• Minimum and maximum controller alarm levels should not be set
at less than 10% or greater than 90% of the full scale range of the
sensor. Limits are 60% LEL or 0.6mg/m
3 for agency performance
certification.
• When configuring or communicating with the transmitter using the
front panel displays, resume monitoring by exiting all menus and
returning to the General Status menu manually. No time outs are
invoked.
• When selecting a new target gas for units with a Searchpoint Optima
Plus, the sensor must be recalibrated.
• XNX Universal Transmitters carrying UL/CSA/FM approvals that are
configured for devices measuring %LEL will not allow adjustments to
the full scale value. The range is fixed at 100%.
• There is a potential loss of sensitivity during exposure to high
concentrations of H2S. Under these conditions, set the control unit to
latch at overrange. In standalone configuration, set alarms to latching.
When resetting the overrange or alarm, verify correct operation of the
transmitter.
• Keep the passwords in a secure area to prevent unauthorized access
to the transmitter. If the passwords are lost, resetting the XNX
transmitter will require a service technician.
• When the XNX transmitter is placed in Inhibit Mode, alarms are
silenced. This will prevent an actual gas event from being reported.
Inhibit Mode must be limited to testing and maintenance only. Exit
Inhibit Mode after testing or maintenance activities.
• Honeywell recommends periodic bump tests (every 30 days or in
accordance with customer site procedures) to the sensor to insure
proper operation and compliance with the functional safety rating of
the installation.
• As some test gases are hazardous, exhaust the flow housing outlet to a
safe area. Do not use the XNX Universal Transmitter in oxygen-enriched
atmospheres. (In oxygen-enriched atmospheres, the electrical safety is
not given.)
• Exposure to desensitizing or contaminating substances or
concentrations causing operation of any alarm may affect sensor
sensitivity. Following such events, it is recommended to verify sensor
performance by performing a functional gas test (bump test).
• When servicing or replacing sensors, reduce the risk of ignition of
hazardous atmosphere by declassifying the area or disconnecting
the equipment from the supply circuit before opening the sensor
enclosure. Keep the assembly tightly closed during operation.
• Take appropriate precautions when using toxic, flammable, and
pressurized cylinders.
• Delays resulting from transmission errors between sensor and
transmitter extend response times T90 by more than one-third. The
period until fault indication is 10 seconds.
• The HART interface is subject of this EC-type examination certificate
only for the purpose of configuration and maintenance.