NuAire LabGard NU-560-400, Operation & Maintenance Manual

Page: 52 / 103

OM0295
Rev 2 September 2020 Page 52 of 103
the range, a greater chance for alarm conditions would exist due to its closer proximity to the
alarm limits.
Press -/+ to change exhaust volume to the value just calculated using the inflow volume.
NOTE:
Assume downflow velocity is at the nominal value of 60 fpm for exhaust volume calculation
purposes as it will be adjusted during the downflow calibration process.
Press SAVE to enter the exhaust volume value. Exit out of calibration menu by pressing
the home icon and leave motor/blower off.
Step 4: Verify the operation of the manual mode pressure switch at this point. Lower the exhaust
volume to 100 CFM (170 CMH) lower than the standard exhaust lower alarm limit.
• Turn off motor/blower
• Block off supply-air intake using cardboard.
• Lower exhaust volume to the pressure switch low trip point stated below.
Model Low Alarm Limit Pressure Switch Low Trip Point
CFM (CMH) CFM (CMH)
NU-560-400 629 (1069) 529 (899)
NU-560-600 954 (1621) 854 (1451)
If present, remove cardboard from supply-air intake and turn ON the unit’s blower if it is not ON now.
Remove 1 screw from each of the top right and left sides of the control box and rotate control box
forward to access the pressure switch adjustment. Pressure switch must be adjusted while control box
is open. Adjust as needed (the adjustment dial), until the internal supply blower/motor is deactivated.
Then raise the exhaust volume back up to the standard lower alarm limit to ensure the internal supply
blower/motor turns back ON. Finally, adjust the exhaust system back to the correct inflow velocity and
exhaust volume. Reattach control box and test the activation/deactivation of the pressure switch again
when the control box is back in the vertical position.
Step 5: If present, remove direct reading instrument from window access open area and proceed to
downflow calibration
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