UniControl Cleveland Controls AFS-951 Quick Start Manual

Cleveland Controls
Division of UniControl Inc.
AFS-951 in St andard E nclosure,
rated NEMA-1.
DESCRIPTION & OPERATION
The Cleveland Controls AFS-951 Differ-
ential Pressure Sensing Switch is designed
to provide precise operation and convenient
features for industrial and commercial air
handling applications. The AFS-951 can
monitor positive, negative, or differential
pressure (flow) of air and noncombustible
gases. It is commonly used to monitor
combustion air, furnace pressure, ventilat-
ing blower operation, inflatable structure
pressure, fume hood operation, bag house
air flow, dirt accumulation in air filters, and
heat-transfer air flow. The AFS-951 has a
field–adjustable set point range of 0.05"wc
to 12.0"wc.
Adjustable Set Point Air Pressure Sensing Switch
AFS-951-1 in NEMA-4 rated
Enclosure.
COMMON APPLICATIONS
The most common specific application for
the AFS-951 is as a Low Draft (Negative
Pressure) Cutoff Safety Switch for com-
bustion draft control systems.
The general applications of the AFS-951
are:
• Low Positive Pressure Cutoff. (Shut-
down upon insufficient pressure.)
• Low Negative Pressure Cutoff. (Shut-
down upon insufficient draft.)
• Low Differential Pressure Cutoff.
(Shutdown upon insufficient difference
between two samples.)
Model
AFS–951
AFS-951-2 in NEMA-7 and NEMA-9
rated Enclosure.
MOUNTING
The AFS-951 is available in 3 enclosures
designed for surface mounting on any flat,
relatively stable surface free of vibration.
To obtain the lowest operating set point
specification, the control must be mounted
with the diaphragm vertical (Fig 1).
The standard enclosure has mounting flang-
es with four 9/32" mounting holes as shown
on page 4. The NEMA-4 rated model has
mounting flanges with four 5/16" mounting
holes as shown on page 3. The NEMA-7/
NEMA-9 rated enclosure has two mounting
slots as shown on page 3.