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FUME HOOD CONTROLLER / MONITOR
SECTION 1 - INTRODUCTION
FUME HOOD CONTROLLER / MONITOR - Manual |pricecriticalcontrols.com
Product Overview
Laboratory fume hoods serve as
ventilation systems that efficiently
exhaust chemical vapors, mist, and
fumes. Fume hoods also provide a
barrier protecting occupants from
certain reactions, spills, and even fires.
In most cases special fans exhaust the
fumes outside, which greatly dilute their
concentration and reduce their harmful
effects. In some cases a specialized
scrubber is also required to remove the
vapors from the exhaust air.
Fume hoods require constant exhaust
airflow to ensure that none of the air
entering the fume hood ever escapes
back into the laboratory space. This
ensures the safety of the user and of
any other occupants of the room or
building. The exhaust airflow, measured
in cubic feet per minute (CFM), creates
a face velocity across the sash opening.
This is the industry standard measure
of fume hood safety. Typically the
face velocity of a fume hood must be
between 80 – 100 feet per minute
(FPM), but this can vary based on local
codes or the fume hood design. It is
important to note the required face
velocity for the hood being used.
Features
The Fume Hood Controller (FHC) can ensure a safe working environment by
constantly monitoring and adjusting the exhaust to maintain the correct face velocity.
The main control inputs are sash sensors and sidewall sensors. Sash sensors use a
potentiometer attached to the sash to measure the current height. Face velocity in
feet per minute (FPM) is calculated in real time. Sidewall sensors use an extremely
sensitive, low pressure sensor to measure the negative pressure in the hood
compared to the lab space. The Fume Hood Monitor (FHMX) constantly monitors
the fume hood face velocity and can provide real-time fume hood information to
operators and to the building management system (BMS) over BACnet.
• 16 bit – high speed flash based microprocessor with watch dog timer, brown
out reset
• Multi-stage surge protection against voltage spikes on 24 VAC input
• 2 simple connections to sidewall sensors using RJ-12 jacks
• 3 Sash position inputs (10kΩ)
• 2 binary outputs rated at 0.5 amps each, protected with thermal fuse
(RED LED on trip)
• 1 binary output (dry contact)
• 2 analog outputs (0-10 VDC)
• 2 binary inputs
• Pluggable terminal blocks
• Mnet high-speed fume hood network port
• 1 potentiometer input
• 1 pressure port input
• LED’s for Mnet/Lnet data TX/RX, Mnet/Lnet wiring fault, and RS-45 termination
A higher face velocity is not always
safer. Turbulence in the fume hood
can be created by high face velocities
causing issues with spillage/blowback.
CAUTION
