NuAire LabGard ES NU-543-300S, Operation And Maintenance Manual

Page: 51 / 72

OM0239 Page 51 of 72
April 2021
7.7 Airflow Smoke Pattern Test
The airflow smoke pattern test is performed using a smoke source (i.e. smoke tubes) in and around the cabinet workzone
and access opening to determine a visual representation of the cabinet’s containment performance. To perform the test,
the smoke source should be passed through the following areas:
A smoke source shall be passed:
1. From one end of the cabinet to the other, along the center line of the work surface, at a height of 4 inches
(102mm) above the top of the access opening.
2. From one end of the cabinet to the other, 1 inch (25mm) just inside the view screen, at a height 6 inches
(152mm) above the top of the access opening.
3. Along the edges of the entire perimeter of the work opening approximately 1.5 inches (38mm) outside the
cabinet, with particular attention paid to corners and vertical edges.
4. 2 inches (51mm) from the sides up inside of the window at the side channel seals, and along inside of the
cabinet along the top of the work area or immediately below the wiper gasket.
The criteria used to evaluate the smoke patterns is the following:
1. The smoke inside the cabinet shall show smooth downward flow with no dead spots or reflux.
2. No smoke shall escape from inside the cabinet.
3. No smoke refluxes out of the cabinet once drawn in, nor does smoke billow over the worksurface or penetrate
onto it.
4. No smoke shall escape from the cabinet.
7.8 Site Installation Assessment Tests
These tests are performed to verify the sash position, airflow or pressure setpoint where an audible and/or visual alarm will
activate to signify unfavorable operating conditions within the Biosafety cabinet and/or the remote exhaust blower, and
canopy connection performance.
7.8.1 Sash Alarm
Step 1: With sash alar m switch enabled, raise the sliding sash 1” (2.5cm) above the manufacturer’s
designated sash height for normal operation. Verify that the audible/visual alarm activates/sounds.
Step 2: Return the sash to its normal operating height.
Note, if necessary, adjustment of the sash alarm switches can be accomplished by:
Behind the right side faring there is a cover panel that needs to be removed.
Then you can access the microswitches and adjust the trip point. Adjustment
is not just vertical, but as you see in the following picture, we have allowed tolerance for rotational
adjustment too. Sometimes how the window switch roller is positioned
will affect its activation point.
Use a nut driver to loosen the switch plate, adjust and re-tighten
7.8.2 Airflow or Pressure Alarm (when installed)
Step 1: Measure and record the speed control operating voltage at the speed control test points using a
voltmeter.