Dwyer CBAS User Manual

Series CBAS Belt Alignment Switch

Specifications - Installation and Operating Instructions

Bulletin PC-CBAS

The Series CBAS is a rugged and reliable conveyor belt align-

ment switch. The compact die cast aluminum housing is de­signed for easy installation. The switch cover allows for simple
access to wiring terminals and CAM adjustments. Belt alignment
switches are typically used in pairs with one switch on each side
of the conveyor belt mounted near the first and/or last pulley of a
conveyor. Each series CBAS is equipped with two micro switch­es, allowing one actuation angle for small belt deviations and a
second actuation angle for extreme belt deviations. The actua­tion angles are factory set at 20 degrees and 35 degrees, each
actuation angle can be easily adjusted in the field to fit any ap­plication.

APPLICATIONS

• Conventional Belt Conveyors

• Ship Loading/Unloading Systems

• Stacker/Reclaim Conveyors

• Apron Feeder Conveyors

• Tripper or Shuttle Conveyors

• Crane, Shovel, or Drag Line Limit Switch

• Heavy Duty Limit Switch

INSULATORS

MICROSWITCHES

CAMS

INSIDE VIEW

2X 2-11/64

[55.17]

5-1/8

[130.18]

75°

2X 1-1/2

[38.1]

5-49/64
[70.25]

5-21/64

[135.33]

0-RING

5-9/16

[141.29]

LEVER

2X 3/4˝ NPT

3/16

[4.76]

1/4

[6.35]
51/64

[20.24]

ø2-3/8

[ø60.33]

1-15/32
[37.31]

TOUCH
PULLEY

1-63/64

[50.4]

3-43/64
[93.27]

CASE

2-9/16
[65.09]

2-9/16
[65.09]

10-9/16

[268.29]

COVER

3-11/32
[84.93]

29/32

[25.02]

2X 13/32 [10.32]

MOUNTING HOLES

COVER BOLTS

4X M10

9/32

[7.14]

SPECIFICATIONS
Temperature Limits: -4 to 140°F (-20 to 60°C).
Enclosure: Die cast aluminum.
Enclosure Rating: NEMA 6 (IP 67).
Switch Type: 2 SPDT.
Electrical Rating: 10 amp @ 125/250 VAC; 1/2 amp @ 125

VDC.
Electrical Connection: 3 screw type, common, normally open,
normally closed.

Electrical Conduit: Two 3/4" female NPT.
Activation Angles: 20 degrees and 35 degrees (adjustable).
Activation Force: 0.8 to 1.2 pounds.
Control Type: Automatic reset.
Weight: 6.4 pounds.

DWYER INSTRUMENTS, INC.

Phone: [phone] www.dwyer-inst.com

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A. Fax: [phone] e-mail: [e-mail]

Operation Principle

The CBAS is typically installed in pairs on both sides of the belt
and positioned 1-6 feet from the head or tail pulley.

The touch roller is deflected by the deviation of the conveyor belt
from a vertical position to 75 degrees, and when the deviation is
restored, a spring will return the touch roller to the vertical
position when the belt is realigned. Cams are preset to turn on
or off the micro switches when the touch roller is deflected. When
the touch roller deviates 20 degrees the first micro switch will
change state, and when the touch roller is deviated 35 degrees
the second micro switch will change state.

Detection (Standard 1C X 2 Output)

TERMINAL NO. TERMINAL NO. TERMINAL NO.

0°

1

3

18˝ 20˝(ON)

2

5

4

* Switching frequency: 20 times/min.

• Number of contact: 1C x 2 output.

TOUCH ROLLER

INSULATING PLATES

CASING

PACKING

33°

35°(OFF)

MAX. SLANT ANGLE 75°

MICROSWITCHES

6

3/4˝ FNPT CONNECTION

CAMS

SPRING

Fig. 1 Construction of CBAS