Cerus is offering the great bargains on a selection of motor control products.
 Please visit the bargain page for details, or call 1-800-962-3787. 

Contractors: Learn how to keep profit, while eliminating
confusion by supplying your own starters.

Selecting a starter is not difficult
Selecting the starter appropriate for the project is actually a very simple step by step process.
1. Determine the phase, voltage and horsepower.
2. Decide whether you need a Combination or Standard starter.
3. Choose the enclosure based on indoor or outdoor application.

Starters are not tough to install
With no external components, a Cerus Smart Starters is an easy straightforward installation process.With damper control, built in fireman's ovveride, and proof of flow these starter save you valuable time with fewer components. Plus, the wide-range overloads eliminate call-backs due to mis-sized heaters.

Great starters are not expensive
Cerus offers extremely competitive prices on all their motor control products.  Contact your local dealer for more information: Rep Locator

Check out our new industrial catalogs, complete with updated product features, new pump products and streamlined products specs & ordering tables.  The message?  We respond. 



To Get your hands on one of these you can call your sales rep at 1.800.962.3787, or request a catalog online at: www.cerusind.com
The pdf version is also available on our home page Catalog PDF Link

GREEN FACTS as published by the U.S. Green Building Council. 

The built environment has a profound impact on our natural environment, economy, health, and productivity.

In the United States alone, buildings account for:
•    72% of electricity consumption,
•    39% of energy use,
•    38% of all carbon dioxide (CO₂) emissions,
•    40% of raw materials use,
•    30% of waste output (136 million tons annually), and
•    14% of potable water consumption.

Benefits of Green Building

Environmental benefits:

• Enhance and protect ecosystems and biodiversity
• Improve air and water quality

• Reduce solid waste
• Conserve natural resources

Economic benefits:

• Reduce operating costs
• Enhance asset value and profits
• Improve employee productivity and satisfaction
• Optimize life-cycle economic performance

Health and community benefits:

• Improve air, thermal, and acoustic environments

• Enhance occupant comfort and health
• Minimize strain on local infrastructure
• Contribute to overall quality of life

Original Source/ More information at:
USGBC Green Building Research

Please share all comments and questions under the CERUS FORUM section of the blog, located on the right hand side of your screen.  We look forward to hearing from you!

- The Cerus Industrial team

 

CERUS INDUSTRIAL DEVELOPS SMART STARTER FOR BUILDING AUTOMATION

 

Beaverton, OR: Cerus Industrial, a leader in motor controls for the building automation industry, introduced their intelligent Building Automation Starter (BAS) with BACnet communication for building control systems.

 

        “This new starter fills the demand in the market for better control and better energy savings of small motors used with building control systems,” said Andre Perra,President of Cerus Industrial. “A typical installation of our new BAS starter will save an end user $100 to $300 per year with better control, efficiency and maintenance. It’s also easier to integrate over conventional motor starters with direct communication to a building control system. That saves $100 to $200per unit by eliminating extra peripheral control and monitoring devices.”

 

        In almost every project where building control systems are used, there are simple on / off motor starters used to control small fans and pumps in a building.Unlike larger motors which run under variable speed for energy savings, smaller motors (1 to 5 hp) typically run at 100% speed. The energy savings are realized through centralized control and monitoring of the motor with a building automation system. With conventional starters, building management systems must control and monitor the drive by using relays and sensors that must be installed in addition to the starter.

 

        The BAS starter is designed specifically for building automation applications and as such, comes complete with built-in sensors and monitors required for building automation systems. It also has the added benefit of a single point of communication and control through BACnet communication, the preferred protocol for building automation systems. Monitoring is integrated into the intelligence of the starter, providing important supervisory and maintenance information.Damper and actuator control functions also reduce control points on the building management system, improving throughput and performance while reducing installed cost.

 

        TheBAS starter is available from ¼ HP to 300 HP, and is sold exclusively through Cerus Industrial’s Dealer Network.

 

        If you would like more information about this topic, or to schedule an interview with Andre Perra, please contact Brittany Hanson at 503-270-5177 or by email at brittany.hanson@cerusindustrial.com.

                                                                                                                                                -End-

 

 

                

Interrupting Ratings and Short Circuit Current Ratings[1]

The 2005 National Electrical Code (NEC) [Article 409.110]addressed the need to accurately identify and label an industrial control panel’s Short Circuit Current Rating (SCCR). This requirement is necessary to ensure the integrity of the panel and the safety of personnel during a short circuit situation.

The NEC also requires an SCCR for:

• Industrial machinery electrical panels [Article 670]
• Multiple motor HVAC equipment [Article 440]
• Meter disconnect switches [Article 230]
• Multiple motor controllers [Article 430]

Article 409 was added due to the dangerous and common misconception by equipment manufacturers that the circuit breaker’s interrupting capacity or the fuse’s interrupting rating in the panel’s feeder circuit is also the panel’s SCCR. In reality, the panel’s SCCR is directly related to the current-limiting capabilities (opening time) of the protective device in the feeder circuit and the individual panel components’ SCCR. In most cases, a panel’s SCCR is less than the interrupting capacity or interrupting rating of the over-current device.

 

Installation Considerations

Also, keep in mind that an existing panel being moved to anew location within a facility still requires verification that its SCCR is greater than the new available fault current. As the panel is moved closer to the electrical service, the available fault current can increase, and the panel needs to withstand this new level. Even if the panel isn’t moved and the available fault current increases from the utility company, this verification needs to be done to ensure a safe environment.

 

How is a panel’s SCCR determined?

NEC Article 409.110(3) states that the SCCR shall be based on a listed (i.e. UL tested) assembly or an approved method of calculation.

 

Since this NEC rule in 2005, Cerus has been working with UL to verify all of our drives, starters and control panels carry a UL approved SCCR rating. For example, Cerus Drives are rated for up to 100,000 ampere interrupting capacity when installed with a UL approved breaker. A Cerus BAS combination starter exclusively uses Cerus UL tested and approved components that provide a UL rated SCCR of up to 100,000 amperes.

 

For more information, or concerns about interrupting ratings for your particular installation, please contact our knowledgeable Cerus sales representative who will be happy to answer your questions.

 

Electronic Coils on CRC 100 – CRC 800

The electronic coil provides dramatic improvement in operation over standard coils, offering an extremely wide operating voltage range and a very low consumption for the size of the contactor. For example, a typical 400 Amp contactor with a 120 volt coil will draw over 1 amp on inrush and holding current of 30 to 40 milliamps. With our electronic coil in a comparable size the inrush is only 393 milliamps and holding current is less than 15 milliamps. This will save significantly in sizing power transformers for the coil. Additionally the electronic coil has an extremely wide range of operation- for the 120Volt example above the coil is actually a100 – 200 Volt coil with a AC or DC operation!

In addition to these performance improvements over standard coils, the electronic coils offer one other operational improvement: Jam Protection. This feature shuts off the coil current in the event of a mechanical jam within the contactor. This prevents the coil from overheating and potentially catching fire- a real possibility with larger contactor coils,particularly on standard coils that draw over 1 amp! In normal operation most users will not ever see this feature in operation. However, when the electronic coils are used with mechanical interlocks, the jam feature may prevent smooth operation if there is not sufficient overlap between the opening and closing of the two contactors. If you plan to use our 100 amp or larger contactors with a mechanical interlock, contact your Cerus representative for application recommendations.

 

Cerus electronic coils for CRC-100 -800:

• Wide range and easy to apply.
• Low current consumption for energy and cost savings.
• Jam protection for safety.

 

Basic Float control pump package or advanced pump package?

                If you are working on pump systems with float control, Cerus has two duplex alternatives: basic and advanced.  So,when should you use a basic package and when should you use an advanced?Generally speaking the basic system is just that- basic with no intelligence built in. It is great for cost sensitive projects or for temporary installations. The advanced system includes our state of the art PLC with intelligence and flexibility to suit almost all applications. Additionally the advanced package includes our electronic overload and manual motor starters for both branch and motor protection, while the basic includes our thermal overloads with differential phase failure protection. So the advanced package is great for maximum protection and application flexibility.  The summary table below details the key differences between both packages. Still not sure? Give us a call and we will be happy to determine the best package for your application.

Feature	Basic	Advanced
Float Control	4 Floats	3, 4 or 5 Floats selectable
Alternation	Manual by switch or optional alternating relay	Automatic
Motor Protection	Differential Thermal Overload	Wide range electronic overload with phase failure protection along with MMS for branch circuit protection
Control Voltage	120 VAC standard, 24 VAC optional	24 VAC standard
Lag pump start / stop delay	Not available	Standard, adjustable
Hand / Off / Auto Switch	Standard	Standard
High Level alarm and alarm contact	Standard	Standard
Run Light	Standard	Standard
Automatic Fail pump switch	Standard	Standard
Horn	Optional	Optional
Run Hour Meter	Optional	Optional
Broken wire or bad float detection	Not Available	Standard
Float input filter to eliminate noise or float bounce issues	Not Available	Standard

 

 

Tech Tip: Pilot Devices-

 

There are many sources of Pilot Devices available in the market. When specifying or purchasing pilot devices here are some key design and construction details you should look for in industrial applications:

 

• Double screw metal mounting bracket. This is the most structurally sound way to mount your pilot devices on a operator panel. Pilot devices that use single screw or plastic clamp are prone to slip or loosen over time.
• Screw in contact blocks. While clip in blocks are great assembly time savers, they are much less secure and can easily be knocked off inadvertently or pop off in extreme conditions.
• Contact blocks rated for at least 1 million operations.
• Tough metal bezel for pilot heads. The metal bezel stands up to a high amount of abuse and protects the switching mechanism from bumps and blows from operators and their equipment.
• Vibration and shock resistance up to 200 times the force of gravity.
• Up to 600 VAC contact ratings.
• UL, CSA and IEC ratings. Tested to NEMA standards.

 

Of course Cerus Pilot Devices meet or exceed all of thesecriteria. If you are using Pilot Devices in an industrial application, contact your Cerus representative for your free sample.

IEC vs. NEMA Contactor Ratings:

Part 1 Normal duty

 

Many customers ask for us to explain the difference between NEMA sizing and IEC sized contactors and starters, and how a dual rated IEC and NEMA contactor or starter compares with a NEMA only equivalent. In this two part tech tip we will explain how to size both NEMA and IEC size contactors, and how they differ in performance.

IEC ratings for contactors are sized based on application and motor ratings. For AC motors there are four utilization categories:

 

AC1- Resistive loads such as heaters with a power factor greater than .95

 

AC2- Starting, plugging, inching and jogging of slip ring motors.

 

AC3- Line starting and breaking during normal running of standard squirrel cage inductive motors. Application examples include lifts, conveyers, pumps, fans etc. This is considered ‘normal’ duty for AC motors.

 

AC4- Plugging, inching and jogging of squirrel cage and slip ring motors. Application examples include cranes, hoists, printing machines, etc.

 

IEC contactors are sized precisely based on one of the AC utilization ratings noted above. Normal duty or the AC3 rating is typically used for sizing the contactor. For example a 32 amp IEC contactor like our CRC 32 is rated for 32 amps full load current at 220 to 460VAC in AC3 applications. To size the contactor properly you will need to know the voltage, current and HP and use the appropriate AC rating.

 

NEMA contactors are similarly rated for general purpose line starting and breaking during running for standard squirrel cage motors. The major difference is that the NEMA ratings are broader and have a small amount of margin built into the ratings to cover the broader range. NEMA starters are rated by size: 00, 0, 1, 2, 3, 4, 5, 6 and 7. To size the contactor you need to know only HP and voltage.

 

At Cerus we dual rate our contactors for both NEMA and IEC ratings. Our NEMA rated contactors meet the NEMA sizing requirements and the IEC ratings for that particular size contactor. Using our CRC 32 as an example once more, we see it is also rated as a NEMA Size 1 contactor. To size a dual rated contactor like our CRC 32 you will need HP, voltage and current (current is needed to insure that the motor FLA does not exceed the contactor AC3 rating since this is a design limitation).

 

In summary, for dual rated or IEC rated contactors you will need to size a contactor or starter based on HP, voltage and current, while a NEMA contactor or starter is sized only by voltage and HP. For general duty applications (AC3), Cerus CRC contactors that are dual NEMA and IEC rated, have similar or superior performance to NEMA only contactors. Next time we will look at how the two compare in heavy duty AC4 applications with a large amount of plugging, inching or jogging.

NEMA vs. IEC contactors Part 2:

Heavy duty applications

 

Last time we looked at how NEMA and IEC contactors differ in sizing for general applications. This time we will look at the differences in applications which require plugging, inching and jogging, or AC4 utilization category as defined by IEC. As a reminder there are four main utilization categories for IEC contactors:

 

AC1- Resistive loads such as heaters with a power factor greater than .95

 

AC2- Starting, plugging, inching and jogging of slip ring motors.

 

AC3- Line starting and breaking during normal running of standard squirrel cage inductive motors. Application examples include lifts, conveyers, pumps, fans etc. This is considered ‘normal’ duty for AC motors.

 

AC4- Starting, plugging, inching and jogging of squirrel cage and slip ring motors. Application examples include cranes, hoists, printing machines, etc.

 

NEMA and IEC have normal duty ratings for contactors that follow AC3 utilizations as we talked last time. For AC4 use, both NEMA and IEC will require a derating.

 

NEMA sizing for plugging inching and jogging follows a standard sizing table. This table results in approximately a 20 to 70% derating compared with normal duty. This table does not specify, nor does it require a life cycle rating be published. So while a NEMA contactor may perform at this derating level, the impact on life cycle ratings is dependent on the manufacturer.

 

IEC deratings for AC4 depend on life-cycle ratings the end user wishes to maintain. With our CRC 32 as an example (which is also rated as a NEMA Size 1 contactor), the NEMA derating table will derate the contactor 50% at 460 volts. Using this NEMA derating for the contactor, the lifecycle rating for the contactor will also reduce to 10% of the AC3 rating.

 

It is difficult to compare NEMA contactors and IEC contactors for AC4 utilization, since NEMA life cycle ratings are usually unpublished information and is dependent on the manufacturer. In general though, the IEC rated contactor will need to be sized more carefully when used in AC4 applications than a NEMA only contactor. In both cases life cycles will be reduced and if a higher lifecycle is needed, then the contactor sizing will need to be derated further, or a higher size contactor will need to be selected to maintain the lifecycle rating and load rating desired.

 

This is probably the biggest area of misapplication when NEMA customers switch to IEC style starters. Lifecycle curves are available in our technical publications for contactors which can assist you in making the right selection for your application (insert weblink). A good rule of thumb with our CRC series contactors for AC4 applications is to use a contactor 2 to 3 times higher than the load rating at AC3 to have a similar life cycle rating. Or simply call us at Cerus to find the right size- NEMA or IEC!

Tech Tip: BAS Starters for Indoor Air Handlers

 

If you regularly order and quote indoor air handlers this tech tip will help you improve your competitiveness and reduce long term operating costs.  The most popular indoor air handlers offer an option for a built in starter. When this option is selected, you will receive a thermal overload starter for an additional price of approximately $1000. Mounted in the access door area it reduces the access door from 30 to 12 1/4”, making field replacements of belts, pulleys etc. a challenging task.

 

Instead, on your next indoor air handler, use a BAS starter.Simply order the air handler field mount ready for the starter (this usually is 

a factory option of $175). A BAS starter can then be mounted outside the air handler keeping the access door free and clear. The net result is your customer gets a superior starter with electronic overload protection, a five year warranty and reduced long term operating costs. You save several hundred dollars on the package, making you more competitive — a true win-win!

 

Indoor Air Handler Built in Starter or BAS?

	Built in Starter	BAS
Overload Protection	Thermal	Electronic
Jam Protection	Per thermal curve (typically 10 seconds)	Included, trip in 3 seconds.
Phase fail protection	Slow usually 30 to 1 min	Included, trip in 3 seconds
Direct Digital Control	Requires interposing relay	Direct wire
Warranty	One year	Five years
Operating costs	Access door limit increases long term maintenance costs	Access door unimpeded for lower maintenance costs.
Installation costs	Pre Installed	Electrician 50- $100.
Starter Cost	$1000+	List price $575 +$175 field mount option on air handler
Total Savings		$200 to $300

Tech Tip: BACnet BAS saves installation and lifecycle costs:

The BAS with BACnet has the potential to save significant installation costs with every installation. With BACnet you have one single point of communication and control. Look at this example:

 

	Standard Starter with Thermal Overload	BAS with BACnet
“RIB” style relay for automation input	Required to interface with building automation system	Not required. Cost plus labor savings $50 to $75
Hand Off Auto Status	Not available	Included in BACnet communications
Status Current Sensor for building automation system	Must add and wire current sensor to the starter	Included at no extra charge, status is built in to BACnet. Cost plus labor savings $75 to $125.
Phase loss and phase failure protection with remote alarm to building automation system	Must upgrade to electronic overload and wire alarm to building automation system.	Standard electronic overload, alarm information is communicated on BACnet. Cost plus labor savings $200 to 300
Alarm status information on other control inputs, power failure, runtime, overload reset count, power failure count and more	Unavailable at any price	Priceless for the end user and building owner trying to maximize uptime and reduce lifecycle costs.

 

In terms of value added engineering, the BAS starter with BACnet is a tech tip worth remembering. Call your Cerus dealer or sales rep for more information.

Advantages of a Comprehensive Motor Protection

 Frank Martino- Power Quality and Drives

   A motor winding has a generally accepted life expectancy of 18 years *
when operated at rated internal temperatures. However, bearings often
fail before the winding. Thus the objective of providing a quick response
with motor overload protection is to have the benefit of the maximum
lifetime of the motor winding.

  Consider the case of the bearing failure in which the bearing places a
drag on the motor shaft, as was mentioned above. If the failure is detected
by an overload Class less than Class 10 or by RTD sensors that are
imbedded within the motor, then that early detection will allow the motor
to be taken out of service for perhaps a one day bearing replacement
rather than a three or four day period for rewind and repair of mechanical
damage caused by bearing collapse.

Avoiding the burn out

  American industry has standardized on Class 20 overload protection
for motor control. The Europeans have standardized on Class 10.
 
  Class 20 will give a nominal 590 second trip (9.83 minutes) at an
overload of 125% of full load amps, a 29 second trip at a 500% overload,
and a 20 second trip at a 600% overload. Thus, a motor that is stalled and
drawing locked rotor amperage will be taken off line in 20 to 29 seconds.
However, a motor that draws a continuous locked rotor current can be
expected to burn out before 20 seconds.
 
  Class 10 will give a nominal 230 second trip (3.83 minutes) at 125%
overload, 15 seconds at 500% overload, and 10 seconds at 600% overload.
 
  Class 30 has a longer time delay to be used on high inertia loads that
require a long acceleration or have shock loading that causes repetitive
motor inrush.

  The Model CRP series overload relays by Cerus Industrial are infinitely
adjustable for Class 1 to 30 by setting the trip time from 0 to 30 seconds.
The set time is the trip time at six times the set current.

  The digital, solid-state CDP series is adjustable for Class 1 through Class 60.
The wide range of class adjustments with the Model CDP will allow the relay
to be adjusted for the maximum protection of the motor. Thus, if a motor is
normally up to running speed in six seconds then the overload relay may be
adjusted for Class 1 with a nominal trip time of 12 seconds at 125% overload.

  A typical overload event is that of a motor bearing failure in which a
bearing begins to seize the motor shaft but yet still allows the shaft to
turn. This type of bearing failure causes a continuous drag on the motor
rotor, causing a high motor current. If the bearing causes, for example, a
125% overload, the overload will be sustained for the 590 second delay of
Class 20 or the 230 second delay of Class 10 and may end in winding burn
out before the overload relay takes the motor off line. A lower Class
protection will take the motor off line in less time. Model CDP relays
will then give an indication that an over current condition took
place rather than a phase loss or other fault. The bearing problem can
then be detected and the bearings replaced before the motor burns out.

  The CDP relay also has a bar graph which indicates load is approaching
thermal limit. The graph indicates 60 to 110% limit which, if monitored
regularly, can give a warning that a problem is developing.

  In addition, the CDP relay will give a digital readout of amperage
on each of the three motor legs.

Model CDP will sense a stalled or locked rotor condition and will shut
down the motor independently of the Class time delay. The Stalled Rotor
Protection will trip when load current is more than 180% of FLA for 5
seconds after start. The Locked Rotor Protection will trip when the motor
draws locked rotor current for .5 second. Stalled or Locked Rotor detection
is the only type of protection against load jam or bearing seizure that will
allow a motor to be shut down with any possibility of preventing a winding
burn out.

Single-phasing Protection via Current Sensing

  The standard melting alloy or bimetallic heating element relays,
such as the Cerus Industrial Model CTK, offer single-phasing
protection by virtue of the remaining two motor legs drawing more
current to compensate for the lost leg. The relay will then sense
the increased heat that is generated by the current and see an
overload. Shut down of the motor, however, will be subject to the time
delay that is inherent within the heating element type relays.

   Many electronic single phasing protectors are voltage sensitive. The
inherent problem that arises is that a three phase motor that looses one
phase will begin to act like a transformer. The un-powered winding then
generates an output voltage that is sensed by the protective relay. As a
result, the relay, if not adjusted properly to the characteristics of the
specific motor, may not sense a loss of power and the motor will continue
to operate rather than be taken off line.

   The only positive solution is a relay that senses motor current. When
current in any motor leg ceases, the relay will shut down the motor in
three seconds without being affected by either thermal time delay or
motor transformer action. Cerus solid state overload relays Models
CRP and CDP are current sensing relays. For high amperage motors, use
Models CRP22-3S or CDP06-S. Set the current trip for 5 amps and use
three current transformers which have 5 amp secondaries.

 

Fault Indication, Electronic Relays, and Inductive Spikes

  The Model CRP solid state relays require a power supply of 100
to 260 VAC, 50/60 Hz, and the Model CDP requires either
110 VAC nominal or 190 to 240 VAC, 50/60 Hz.

  There are current sensing overload relays on the market which are
assembled to the motor contactor so as to have the internal electronics
powered by the same power that feeds the motor. Those relays are then
subjected to the continuous inductive spikes that are generated by
electric motors. Without sufficient internal transient suppression, the
relays could fail after a period of time due to the electronic components
being degraded by the repetitive motor generated transients.

   An advantage of using a control transformer input with the Models CRP
and CDP is that it will provide isolation which will protect against
external transients that would enter the power input of the relay. If the
240 VAC used on the CRP or CDP is taken from the motor power source,
then the relays will be subjected to the motor transients. Although
suppression is built within the relay, an external suppressor
is available for extra protection and can be wired in parallel with
the input terminals of the relay. Use Cerus suppressor Part Number AS-3.

Conclusion

Enhanced motor protection will therefore not only lower motor
rewinding and repair costs but will also lower over-all down time and
yield an increase in production.