OM0283
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Rev 2 July/2021
7.5.3
Setpoint Parameters
Setpoint parameters establish both the nominal airflow velocity, as well as the alarm limit velocities. Typically
theses are default values factory set for the required airflow range as tested and listed by 3
rd
party agencies.
However, they may be altered in special cases for modified non-listed special cabinets. In addition to setpoints,
filter life parameters are established using motor rpm. To determine filter life, the starting motor rpm is entered
after the first airflow calibration is performed with clean filters. The maximum rpm is a known fixed value based
on the DC ECM motor used. The difference between the maximum and current rpm determines the filter life
percentage. The filter life percentage starts at 100% and as the current rpm increases due to filter loading, the
filter life decreases.
Inflow Velocity
Default values
Low Limit 90fpm
Setpoint 105fpm
High Limit 120fpm
Filter Life
Filter Life Calibration
Maximum rpm
–
initial rpm = Total available rpm
Total available rpm
–
latest rpm = Filter rpm available
Filter rpm available ÷total available rpm = (Filter rpm used -1) x 100=HEPA filter life
Setpoints
Inflow
Filter Life
DnFlow Set Pt 60
Inflow Velocity (fpm)
Low Limit: 90
Setpoint: 105
High Limit: 120
Filter Life
Initial rpm: 1000
Latest rpm: 1100
Maximum rpm: 1375
Summary of Contents for LabGard D NU-543-400
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