NuAire LabGard NU-543-300E, Руководство по эксплуатации и обслуживанию

Страница: 51 / 72

OM0284 Page 51 of 72
Rev 2 July/2021
7.6 HEPA Filter Leak Test
In order to check filter and filter seal integrity, the HEPA filter media and seals must be directly accessible by the measuring
instrument. The challenge material (i.e. PAO) should be supplied in the rear center of the workzone over the intake slots.
The upstream challenge tubing/port being common for both filters is located under the work surface with a red cap.
7.6.1 Supply Filter
The diffuser plate, placed below the HEPA to protect the filter during normal usage, may be removed as follows:
The diffuser is secured to the cabinet shell by #1/4-20 acorn nuts located immediately behind the front viewing
window. After removing the fasteners, drop the front of the diffuser plate several inches and pull forward gently.
Note that the diffuser is purposely a tight fit - it is held to the back wall of the cabinet interior by a light push - fit with
projecting studs. To avoid the window high alarm during the filter integrity check, it is desirable to enter the Service
menu and turn on the blower.
Air currents in the room can sometimes contribute to exhaust entrainment on top of the cabinet. This can lead to false
leak readings. In order to reduce the probability of false leak readings, it is recommended to cover half of the exhaust
HEPA filter while scanning the uncovered section of the exhaust HEPA filter.
7.6.2 Exhaust Filter
The exhaust filter is typically more difficult to check since protective grills, charcoal filters, or exhaust transitions could
cover the filter. Access panels are usually provided and should be removed. If an air gap exhaust transition is provided,
the air gap must be sealed with duct tape or other suitable means to prevent contaminated air from migrating into the
exhaust efflux. All exhaust blowers/fans should be turned off during the check. The exhaust sensor shroud can also be
removed for the exhaust filter integrity check. Replace the exhaust sensor shroud immediately after the filter check to
assure proper operation.
NOTE: To avoid the window high alarm during the filter integrity check, it is desirable to enter into the
Service menu and turn the blower on. To accomplish this, perform the following:
•
Press and hold key, then press ENT ↑ and ↓ keys sequentia lly releasing the key after the
3 key sequence.
The following service parameter display should appear
Navigation through the service parameter menu is the same as the operator menu.
•
Press key to back up one level or repeated times to return to normal run or standby mode.
Note: If the upstream challenge port is deemed contaminated and not accessible, use both downflow and
exhaust volume for determining challenge concentrations. Use following area information below
with average downflow velocity and spot-check exhaust velocities as measured to determine
volume (CFM) (CMH).
Model
Size
*Supply Area
(ft
2
)(m
2
)
Exhaust Area
(ft
2
)(m
2
)
Model
Size
*Supply Area
(ft
2
)(m
2
)
Exhaust Area
(ft
2
)(m
2
)
300E 6.33 (.588) 1.61 (.150) 500E 10.74 (.998) 4.17 (.387)
400E 8.53 (.792) 3.06 (.284) 600E 12.95 (1.203) 5.00 (.465)
* Measured 4 inches above the bottom edge of the window.
Laskin Nozzle Concentration Formula
# Nozzles x 135 CFM x 100 ug/L Challenge
Downflow (CFM) + Exhaust (CFM) Concentration (ug/L)
# Nozzles x 229 CMH x 100 ug/L Challenge
Downflow (CMH) + Exhaust (CMH) Concentration (ug/L)

=
=
Service Parameters
Configuration
Setpoints
Calibration
Options
