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The Proper Installation & Maintenance of LPN-H.
All power and signals must be de-energised before connecting any wiring, or altering any Jumpers or Dip Switches.
MOUNTING.
(1)
Mount in a clean environment.
(2)
Do not subject to vibration.
(3)
Avoid mounting near power control equipment.
(4)
Mount the LPN-H-W on a solid wall or panel, where air will flow freely around it.
(5)
Mount the LPN-H-D through a LPN-H-F 100mm flange, into the duct.
(6)
Always mount the LPN-H so that the protective cap is either horizontal or sloping downwards. This helps prevent
condensate build up in high humidity situations.
(7)
Avoid mounting where the protective cap will get wet as this may cause false readings.
(8)
Again ensure there is adequate air flow over the sensor.
(9)
To maintain compliance with the EMC Directives, the LPN-H metal enclosure must be properly earthed, with
appropriate input / output entry points, cabling and filtering.
WIRING.
(1)
All cables should be good quality overall screened INSTRUMENTATION CABLE with the screen earthed at one
end only.
(2)
Signal cables should be laid a minimum distance of 300mm from any power cables.
(3)
For the two, 2 wire current loops Austral Standard Cables B5002CS is recommended.
(4)
It is recommended that you do not ground current loops and use power supplies with ungrounded outputs.
(5)
Lightning arrestors should be used when there is a danger from this source.
(6)
Refer to diagrams for connection information.
4~20mA HUMIDITY
4~20mA TEMPERATURE
COMMISSIONING.
(1)
Once all the above conditions have been carried out and the wiring checked apply power to the LPN-H loops and
allow five minutes for them to stabilize.
(2)
To check humidity accuracy use a calibration standard %RH device in the same location. Check that the readings
agree within 2% + % error of the calibration device. Alternatively expose the LPN-H to a known %RH atmosphere,
and check the readings agree within 2% + % error of atmosphere.
All readings should be referenced against the ASTM Relative Humidity tables, and allowances made for pressure
effects if necessary. Any differences can be corrected using the Humidity Zero and Span Pots on the LPN-H.
(Clockwise to increase the output reading, and anticlockwise to decrease the output readings.)
(3)
To check temperature accuracy use a calibration standard RTD in the same location. Check that the readings
agree within 0.1% of the calibration device. Any differences can be corrected using the Temperature Zero and
Span Pots on the LPN-H. (Clockwise to increase the output reading, and anticlockwise to decrease the output
readings.)
MAINTENANCE.
(1)
Repeat 2 and 3 of Commissioning - breathing on the protective cap will cause the %RH and Temperature readings
to alter.
(2)
Do it regularly - at least once every 6 months.
(3)
Check cables entering the LPN-H head.
CLEANING OR REPLACING THE PROTECTIVE CAP.
If the protective cap becomes dirty it can easily be removed for cleaning, or replaced, as follows:
(1)
Disconnect power from LPN-H.
(2)
Carefully unscrew the cap by hand. No tools to be used - they may damage the protective cap.
(3)
The cap may now be cleaned or replaced.
(4)
Ensure the cap is thoroughly dry before replacing.
(5)
Carefully screw the cap back on by hand, and reapply the power to the LPN-H
NOTE: The LPN-H must not be operated without the protective cap,
as the humidity sensor reading is affected by light.
TEMP
%RH
4.02-4
Intech
INSTRUMENTS LTD
www.intech.co.nz
Christchurch Ph: +64 3 343 0646
Auckland Ph: 09 827 1930
Email:
sales@intech.co.nz
LPN-H 010212 p65
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