Product Overview

SPECIFICATIONS
CLEVELAND CONTROLS
MODEL DFS-221 AIR
PRESSURE SENSING
SWITCH WITH
FIXED SET POINT
Mounting Position: Mount with the dia-
phragm in any vertical plane to obtain
specified operating set point.
Set Point: Fixed to operate on pressure
rise at 0.05±0.02"w.c. (1.27±0.508 mm).
Approximate Switching Differential:
0.02±0.01"w.c.
(0.5082±0.254 mm w.c.)
Measured Media: Air, or combustion by-
products that will not degrade silicone.
Maximum Pressure: ½ psi (0.03 bar).
Operating Temperature Range:
-40F to 180F (-40 to 82C).
Life: 100,000 cycles minimum at 1/2 psi
maximum pressure each cycle and at
maximum rated electrical load.
Electrical Rating:
300 VA pilot duty at 115 to 277 VAC,
15 amps noninductive to 277 VAC, 60 Hz.
Contact Arrangement: SPDT.
Electrical Connections: Male ¼" 90°
quick-connect terminals.
Sample Line Connectors: Two barbed
¼" slip-on connectors.
Sample Line Connections: Connectors
accept flexible tubing.
Approval: UL, FM, CSA.
Shipping Weight: 1.2 lbs.
Accessories
• Sample line probes.
• Orifice plugs (pulsation dampers).
(Figure 4)
(Figure 3)(Figure 2)
ELECTRICAL
CONNECTIONS
(FIGURES 3 & 4)
Before pressure is applied to the dia-
phragm, the switch contacts will be in the
normally closed (NC) position. Control
and alarm functions are wired as shown
in Figure 4.
Nominal Dimensions in Inches (Millimeters)