The DAZIC Zero Speed Switch helps prevent material pileup and detect machine failure, ensuring that your plant operations run smoothly.

1. ZERO SPEED SWITCHES
By CONTROL CONCEPTS USA

2. ZERO SPEED SWITCH: PROTECT EQUIPMENT,
PROCESS, AND PEOPLE
Zero speed switches can help prevent material pileups and detect machine
failure. Just like fire alarms, they are affordable and easy to install — but can
quickly alert you of a problem and prevent thousands of dollars in damage.

3. WHAT IS A ZERO SPEED SWITCH?
Speed switches are attached to rotating
shafts to detect any abnormal change in
rotation speed. These shafts are found
in many types of plant machinery, from
conveyor belts to rock crushers.

4. HOW DO SPEED SWITCHES WORK?
Speed switches monitor a device’s rotations per minute (RPM), and then trigger an
alarm when it falls outside of predetermined limits. They can use different
technologies, which each have their own benefits.

5. HOW DO SPEED SWITCHES WORK?
Electromechanical speed switches are direct-coupled, and mechanically open or
close a set of contacts according to the rotational speed of the switch shaft.
• Trigger point: the speed when the switch trips and sends the alarm is determined by how it
is physically constructed, and any adjustments to its internal components.
• Benefits: Electromechanical switches are a low-cost alternative for process and safety
applications.
• Example: DAZIC 2100, DAZIC 4100, DAZIC 8100

6. HOW DO SPEED SWITCHES WORK?
Electronic zero speed switches are also direct-coupled but use a relay and
electronic circuit to open or close a set of contacts.
• Trigger point: the alarm goes off when the speed does not meet user-defined settings
• Benefits: Electronic switches can be set up with LCDs and device diagnostics, for more
convenience and overall plant efficiency.
• Example: DAZIC ROTOGUARD IV

7. HOW DO SPEED SWITCHES WORK?
Magnetic zero speed switches use a non-contact inductive sensor probe
positioned near the rotating object. Metal flags or magnets are mounted on a disc
or pulser wrap. They generate pulses as they pass through the probe’s
electromagnetic field. The pulses have a frequency that is proportional to the
shaft RPM (rotations per minute).
• Trigger point: If the RPM does not match the speed trip-points that you have set – it is
moving too fast, too slowly, or stops completely – a corresponding relay de-energizes, and
triggers an alarm.
• Benefits: Non-contact speed switches can be remotely controlled, and are ideal for tight
locations, high-vibration installations, or high-temperature environments.
• Example: DAZIC PROX MICRO

8. To avoid nuisance tripping caused by normal pauses in speed (such as start-up or
built-in time delays), speed switches can be programmed to drop out only after a
specified time. Some systems will need an external timer, while others can already
have it built in.
HOW DO SPEED SWITCHES WORK?

9. HOW CAN A SPEED SWITCH IMPROVE PLANT
OPERATIONS?
Prevent downtime. You can lose a whole day of productivity from shoveling
material pile-up because a bucket elevator or conveyor belt broke down. And if
equipment breaks and the process stops, you’re paying your workers to sit around
and do nothing.
Detect machine damage before they’re expensive to repair. Speed changes can be
a sign that equipment needs repair or preventive maintenance. It’s cheaper to fix a
small part now, than to replace equipment down the road.

10. HOW CAN A SPEED SWITCH IMPROVE PLANT
OPERATIONS?
Automate processes. Speed switches are sometimes used to initiate a secondary
process once it reaches a particular speed or pre-programmed setting.
Prevent worker injury. The speed of operating equipment can play a big role in
workplace safety. Speed switches can prevent accidents or injuries caused by
malfunctioning equipment, spillage, or cleaning material pile-up.
Achieve accurate processes. Quality starts with precision. Keep your equipment
running at the right speed and know the moment that there is a problem.

11. WHERE CAN I INSTALL A SPEED SWITCH?
∙ Rotary valves
∙ Bucket elevators
∙ Belt, drag, and screw conveyors
∙ Fans
∙ Blowers
∙ Saw blades
∙ Drive motors
∙ Mixers
∙ Crushers
∙ Agitators
∙ Rolling mills
Speed switches can be installed on any device with a rotating shaft. This includes:

12. WHAT INDUSTRIES USE SPEED SWITCHES?
• Grains, feed and milling
• Bulk materials handling
• General manufacturing
• Sugar processing
• Packaging
• Food processing
• Ethanol/Biofuels processing
• Textiles
• Mining
• Power generation
• Utilities
• Wastewater
Some of the world’s biggest companies use speed switches for smoother, safer,
and more efficient plant operations.

13. WHAT ARE THE BENEFITS OF SPEED SWITCHES?
IMPROVE PROCESS
• Prevent downtime caused by material
pile-up
• Increase plant safety
• Achieve accurate processes
LOWER COST
• Prevent wasted material and lost
manpower hours
• Prevent machine damage from
misalignment and wear-and-tear
• Reveal machine failure and need for
early preventive maintenance

15. WHAT ARE THE DIFFERENT KINDS OF SPEED
SWITCHES?
Zero speed switches differ in their:
• Set-up
• Features
• Performance specifications
• Mounting styles
• Casings

16. TECHNOLOGY USED
• Electromechanical speed switches mechanically open or close a set of contacts.
• Electronic zero speed switches use an electronic circuit.
• Magnetic proximity switches uses a proximity sensor and a microcomputer.

17. SPECIAL APPLICATIONS
Some zero speed switches are designed
for harsh outdoor conditions or
hazardous plant environments.
They can be weather-proof, dust-proof
and explosion-proof.
Look at the product’s National Electrical
Manufacturers Association (NEMA)
ratings.
DAZIC EXPLOSION-PROOF SPEED SWITCHES

18. PERFORMANCE AND FEATURES
Speed switch models cater to different shaft input speeds.
Some perform better for applications that have slower start-ups or operating
speeds, while others can detect not just when a shaft stops but begins to rotate
backwards.
Finding the RIGHT SPEED SWITCH
for your process and equipment is
essential for SAFE, EFFICIENT OPERATIONS.

19. MOUNTING OPTIONS
Zero speed switches need to be securely
mounted and aligned to prevent
damaging the bearings and causing
premature product failure.
Proper installation can include mounted
brackets and couplings.

20. CASE STUDY: The Little Speed Switch that Could
DAZIC® Zero Speed Switches are durable and dependable. Just ask one of our clients.
In 2006, one of the world's largest manufacturers
of sustainable, fiber-based products installed
DAZIC Zero Speed Switches on its conveyor belts.
After many years, sludge build-up was noticed.
It was not enough to stop operations, but it was
sent out for servicing, nonetheless.
DAZIC engineers discovered that the switch was
installed in a system way beyond its specifications.
But instead of breaking down it kept on working
efficiently — it only got dirty.
Read more about the case study published in
powderbulksolids.com.

21. SPEED SWITCHES PROTECT EQUIPMENT,
PROCESSES AND PEOPLE.
To find out more about DAZIC® Zero Speed Switches,
visit https://controlconceptsusa.com/dazic/