Dwyer DSS User Manual

Series DSS Direct-Contact Speed Switch

ø4-3/4

(120.65)

4-7/8

(123.83)

FRONT VIEW

SIDE VIEW

2

(50.8)

1-17/64
(32.03)

8

-63/64

(228.09)

3/4” NPT PIPE TAP

BOTH SIDES

REAR VIEW

7/8

(22.23)

2

-1/2

(63.50)

1-1/4

(31.75)

MOUNTING HOLE PLAN

2-1/4

(57.15)

Specifications - Installation and Operating Instructions

Bulletin E-17

The Series DSS Direct-Contact Speed Switch is a compact switch
designed to include all mechanical and electronic components in one
housing. It will produce an output signal at a predetermined speed which
may be either over-speed, under-speed or zero-speed. Rugged, heavy­duty construction combined with solid state electronics and photo-elec­tric technology makes this one of the most advanced motion detectors
available. Series DSS protects all valuable rotating equipment including
belt conveyors, bucket elevators, rotary feeders or screw conveyors. It
operates in a clockwise or counter-clockwise direction and mounts in
any position.

SPECIFICATIONS
Temperature Limits: -50° to 150°F (-45° to 65°C).
Enclosure: Aluminum with screw cover
Enclosure Rating: DSS-W: NEMA 3S, 4 & 4X. DSS-E: NEMA 3S, 4 &

4X, NEMA 7: Class I groups C & D, NEMA 9: Class II groups F & G.

Switch Type: DPDT.
Electrical Rating: 3A @ 120/240 VAC, 1/10 Hp @120/240 VAC.
Electrical Connections: Screw terminal.
Conduit Connections: (2) 3/4” female NPT.
Mounting Orientation: Any.
Set Point Adjustment: Adjustment screw.
Power Requirements: 105-135 VAC, 50/60 Hz, 210-250 VAC, 50/60

Hz; or 24 VAC/DC depending on model.

Power Consumption: 3 watts.
Repeatability: 2% maximum at constant voltage and temperature.
Pick-up Point: 3 speed ranges at which relay will energize:

Low: 0.1 to 10 RPM;
Medium: 1 to 100 RPM;

High: 10 to 1000 RPM.
Signal Point: Speed at which relay will de-energize. Recommended to
be 15-20% lower than pick-up point.

Start-up Delay: Adjustable up to 45 seconds.
Radial Load on Input Shaft: 125 lbs maximum.
End Thrust on Input Shaft: 100 lbs maximum.
Rotation: Either clockwise or counter-clockwise.
Driving Torque: 1”/lb maximum.
Shaft: 5/8” diameter with 3/16” x 7/8” key.
Weight: 5 lbs (2.3 kg).

PROXIMITY CONTROLS

A DIVISION OF DWYER INSTRUMENTS, INC.
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.

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

Fax: [phone] e-mail: [e-mail]

OPERATING PRINCIPLE

Note: Switch should be concentric with

t

The model CMS motion switch can be driven by one of the following

If
a stub shaft is required, we suggest the use of a 5/8” stub shaft. Use with a
s

The Series DSS Motion Switch senses motion by means of a precision
metal disc mounted on the input shaft. This disc generates measurable
light pulses by a series of slots on its periphery, which rotate past an
infrared light source. A photo-electric sensor monitors the series of light
pulses and converts them to digital electronic signals. Solid state circuit­ry then analyzes the digital signals and activates or de-activates the out­put relay at the pre-set speed.

Field adjustment of the signal set point is easily accomplished by means
of an adjustment screw on the electronics. For under-speed sensing, the
signal point is set below the normal operating speed of the unit. The out­put relay will then de-energize if the speed drops below the signal point.
For over-speed sensing, the pick-up point is set above the normal oper­ating speed. The output relay will energize if the speed exceeds the pick­up point. Zero-speed sensing can be accomplished by turning the adjust­ment screw to its minimum setting. The output relay will then de-energize
when the shaft speed of the unit approaches zero.

INSTALLATION

1. FIGURE 1: Suggested Coupling Arrangement, side view. Direct con­nection through a coupling (preferred means). Note: Switch should be
concentric with the mating shaft. If stub is used, it must be concentric
with the main shaft. If a stub shaft is required, we suggest the use of a
5/8” stub shaft. Use with a split or flexible type coupling.

ustomer’s shaft with

C
concentric stub shaft

Flexible coupling

2. FIGURE 2: Cog Belt Drive (timing) or Roller Chain Drive: A V-Belt drive
is not as desirable because of possible slippage.

LOCATION & MOUNTING

The Series DSS motion switch can be mounted for operation in any posi­tion. The surface to which the switch is affixed should be as flat and as
smooth as possible. Bearing brackets and shim plate sets can be used
to mount the unit directly to the pillow block supporting a shaft. On instal­lations where vibration conditions are not extreme, use 1/4” diameter
machine bolts with lock washers through the four mounting holes in the
base of the switch. (Mounting bolts and lock washers are not furnished
with the switch.) If vibration conditions are extreme, use of a doweling is
recommended through two mounting holes in the switch base. The
switch should be mounted as axially in line, and/or parallel as possible to
the existing shaft, which is to drive the switch. The Series DSS motion
switch can be driven by one of the following means:

Cog belt (timing) or

roller chain drive

3. FIGURE 3: Suggested Spur Gear Arrangement (top view)

ustomer’s shaft with

C

oncentric stub shaft

c

Spur gears

WIRING

FIGURE 4: Electronics View

ormally closed 2

N

Common 1

2

L

L

1

Time Delay

peed Range

S
L

H

M

Use only solid conductors

f 14 AWG of smaller

o

peed set point

S

ndicates relay energized

I

Green LED

Yellow LED

Indicates pulses

Normally open 2
ormally open 1

N

Normally closed 1

Common 1

Remove end cap to expose terminals and pick-up speed adjustment
screw. Wire input power from source to terminals L1 & L2. Be certain to
use the provided ground screw. The output of the Series DSS is a DPDT
relay. There are two sets of output contacts. Each set includes normally
open, normally closed and common. As a result, the unit can be used to
control two separate circuits such as a motor starter and a signal light.

CONDUIT INSTALLATION:

Use only hubs of suitable sizes that are UL/CSA approved for WATER­TIGHT use. Install per the hub manufacturer’s instructions. Be sure the
location selected will provide adequate wire bending space.

SIGNAL SET POINT

FOR USE AS AN UNDER-SPEED SWITCH:

Select the speed range required by changing the switch to LOW for 0.1
to 10 RPM, MEDIUM for 1 to 100 RPM and HIGH for 10 to 1000 RPM.
Turn the set point potentiometer to the counter-clockwise stop. With
motion present on the input shaft and at normal operating RPM, the yel­low LED should blink. The green LED should turn on indicating that the
output relay is energized. Slowly turn the set point adjustment screw
clockwise until the output relay de-energizes. (A “click” will occur at this
point.) Back up until the output relay energizes. Thus, when speed drops
below the set point, the green LED should turn off indicating that the out­put relay is de-energized. If the normal operating speed of the input shaft
exceeds 10 RPM for the LOW, 100 RPM for the MEDIUM or 1000 RPM
for the HIGH, the unit should be adjusted as follows. Turn the set point
adjustment screw clockwise until it reaches the stop. When the speed
drops below 10 RPM for the HIGH, the relay will energize.
NOTE: Typically, the motor contact is wired in series with one of the NO
output contacts and an alarm is wired with one of the NC output contacts.

FOR USE AS AN OVER-SPEED SWITCH:

Select the speed range required by changing the switch to LOW for 0.1
to 10 RPM, MEDIUM for 1 to 100 RPM and HIGH for 10 to 1000 RPM.
Turn the set point potentiometer to the counter-clockwise stop. With
motion present on the input shaft and at normal operating RPM, the yel­low LED should turn on indicating that the output relay is energized.
Slowly turn the set point adjustment screw clockwise until the output
relay de-energizes and the green LED turns off. (A “click will occur at this
point.) with the potentiometer on that setting, if the speed increases the
output relay will energize.
NOTE: Typically, the motor contact is wired in series with one of the NO
output contacts and an alarm is wired with one of the NC output contacts.

FOR USE AS A ZERO-SPEED SWITCH:

Select the LOW speed range by changing the switch to LOW for 0.1 to
10 RPM. Turn the set point potentiometer to the counter-clockwise stop.
This will give a set point of 0.1 RPM. Thus, when the speed drops below

0.1 RPM, the output relay will de-energize.
NOTE: Wiring should be the same as for under-speed applications.

TIME DELAY SETTING

The Series DSS motion switch has a start-up delay that is adjustable up
to 45 seconds. This setting should be set, depending on the application
and the length of time it takes for the conveyor to reach its normal oper­ating RPM. This time delay takes effect upon power-up of the Series
DSS after shutdown. AC power to the Series DSS must be interrupted for
timer to be reset. This delay only effects start-up, avoiding nuisance
start-up alarms.

TROUBLESHOOTING PROBLEMS & SOLUTIONS

PROBLEM: SOLUTION:

No pulses from yellow LED: Check power supply.
Make sure input shaft is turning.

PROBLEM: SOLUTION:

Relay is not energized or de-energized: Check power supply. When
expected. (I.e. green LED not on: Make sure input shaft is turning. Or off
when expected.) Check for proper set point.
Check for proper speed setting.
(LOW, MEDIUM or HIGH)

PROBLEM: SOLUTION:

Alarm sounds when equipment is started: Check start-up delay setting.
Check for proper connections between alarm and relay. AC power must
be interrupted for alarm to reset.

PROBLEM: SOLUTION:

Alarm does not go off when expected: Check power supply. Check for
proper connections between alarm and relay.

MAINTENANCE

Upon final installation of the Series DSS Direct-Contact Speed Switch,
no routine maintenance is required. A periodic check of the system cali­bration is recommended. The Series DSS is not field serviceable and
should be returned if repair is needed (field repair should not be attempt­ed and may void warranty). Be sure to include a brief description of the
problem plus any relevant application notes. Contact customer service to
receive a return goods authorization number before shipping.

PROBLEM: SOLUTION:

Equipment is not shut off when expected: Check power supply. Check for
proper connections between control circuit and relay.

©Copyright 2014 Dwyer Instruments, Inc. Printed in U.S.A. 4/14 FR# R6-443493-00 Rev. 1

PROXIMITY CONTROLS

A DIVISION OF DWYER INSTRUMENTS, INC.

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

Fax: [phone] e-mail: [e-mail]

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.