Nortec NH Series, Installation Manual

Page: 90 / 110

10-40
Page 12
2006-09-15
Table 4. Term Definitions
6. 0-10V DIGITAL HUMIDISTAT SENSOR CALIBRATION
A. PROCEDURE
(1) The humidity sensor is factory calibrated, however, it can be field recalibrated. The
calibration routine can be accessed by pressing and holding down the option button for
five seconds. A new screen will appear with the calibration adjustments.
(a) Press the up or down buttons until calH appears on the LCD screen.
(b) To adjust the calibration press the Option button. The screen should load to
display the current calibration trim.
(c) The calibration trim can be adjusted by pressing the up or down buttons to the
desired level and then pressing the option button to confirm the settings.
(d) Press the Power button to return to the normal display.
Term Definition
RATED AMPS Refers to amps listed on the humidifier specification label.
SHORT CYCLING When the ‘on time’ of the humidifier is less than ten minutes upon a call for humidity. To correct
short cycling, all humidifiers have a capacity adjustment which allows the output of the humidifier to
be reduced as low as 20% of rated output, thus extending the ‘on time’ required to maintain output.
FOAMING This phenomenon can occur in water when the impurities, already in the water, reach an excess
concentration as result of boiling away pure water, and the continued boiling action agitating the
contained water. The humidifier electronics are designed to prevent this occurrence, although in
extreme cases water will foam with little concentration making it necessary to have the drain time of
the water, contained in the cylinder, increased. Foaming is normally caused by short cycling, a
restricted drain, or back pressure. The foam generated in these instances, is conductive and may
lead to a false full cylinder indication if the level of the foam approaches the top of the cylinder.
BACK PRESSURE This can be caused by restriction of steam flow caused by long steam runs; improperly sloped
steam lines; elbows changing the direction of the steam flow from horizontal to vertical without a
drain leg, any plumbing detail allowing the accumulation of condensate; undersized steam line;
improper steam distributor; downward air flow onto the distributor creating excess static pressure at
the steam outlets; or high static pressure ducts (not probable). To overcome excess static pressure
in the duct, a fill cup extension kit should be used. In downflow applications, a downflow distributor
should be used but in some cases the fill cup extension will also be required.
RESET UNIT
(HUMIDIFIER) To reset the humidifier, the ON/OFF switch at the front of the humidifier should be switched to the
OFF position for a minimum of five seconds and then switched back to the ON position.
MONITORED LEG Refers to the primary wire to the cylinder which loops through the current sensing device on the
driver PCB. This wire is terminated at the red cylinder plug at the cylinder. Units with six primary
wires to the cylinder will monitor only one of the two wires, terminating with red plugs.
CONDENSATE Refers to steam that has condensed to a liquid.