I must admit, this blog came to me as an idea because I saw this word on our website and have no clue what it means!

A quick Google search wasn't much of a help, although I did learn about something called a bifurcated divorce (learn more here). Apparently a popular use for this word involves divorce.

I'll assume the definition is a bit different when we are referring to relays. Here is where I saw it on our website, referring to our IDEC RU series of general purpose power relays.

Looking up a few definitions told me that bifurcate means to divide into two parts, to separate into two parts or to fork or divide into two parts.

When referring to relays I finally found a definition on RelayMasters.com (thank you!) - basically it is a contact with two simultaneously operating contact points. Twin (or bifurcated) contacts increase the contact reliability considerably, especially when switching low currents and voltages (dry circuits) and are used for reduction of contact resistance. Bifurcated contacts are twin contacts with the two contact points on one contact member (contact blade). 

Bifurcated contacts reduce contact bounce, increase reliability and assist in switching. Bifurcated contacts conduct the switching more efficiently.

In the past, bifurcated relays were costly and generally special order. As they become more popular, especially in the elevator industry, more companies are stocking and reworking the price structure.

Marshall Wolf Automation is your authorized IDEC distributor for their complete line of relays, industrial DC power supplies, photoelectric sensors, LED pilot lights and much more.

Search all of our IDEC products now!

All About AC Drives

Variable frequency drives are also known as variable speed drives, VFD's, inverters, adjustable frequency drives, motor controllers, AC drives and microdrives.

Variable frequency drives (VFD's) adjust your motor speed to closely match output requirements, typically resulting in energy savings of 10 to 50 percent.

Variable frequency drives save energy. One way they do this is by reducing motor speed as demand decreases.

Are you looking for a drive to run your three phase motor on single phase power? Our TECO EV/JNEV Series is our most popular single phase input AC drive. This is the ideal drive for hobbyists because it is low cost, readily available from stock and easy to use!

Need a recap of the basics? Read our blog: What Are Variable Frequency Drives Used For And Who Should Use Them

If you require a NEMA 1, general purpose drive then we would recommend our AC Tech Lenze SMVector series. Loaded with features yet still competitive, we can ship from stock today!

Read a great article by Tom Robbins of AC Tech Lenze, "Motor Drive Upgrades Boost Industrial Plant Performance" - discussing the value of upgraded motor controls and variable frequency drives (VFD) over conventional fixed-speed motor drives.

Are you working on an HVAC application?

Marshall Wolf Automation carries a full offering of variable frequency drives tailored for the HVAC market. We also have in-house tech support available to help you choose the best drive.

Do you need your variable frequency AC drive installed in an enclosure? We can do that too! We carry the popular Saginaw line of industrial enclosures and can add other components as well.

You can also take a look at this spreadsheet - we list our popular AC drives as well as the properly sized enclosure to go with it!

Marshall Wolf Automation also specializes in the NEMA 3R market for drive panel enclosures and pump panels.

Take a look at NEMA 3R applications we have already solved!

Frequently Asked Questions Regarding Variable Frequency Drives:

Can I use a single phase motor with your variable speed drives?

No. All variable frequency drives work with 3 phase motors only. Single phase drives will operate on single phase power, however, the output is still 3-phase and will require a 3-phase motor.

How do I choose the proper size variable frequency drive (VFD)?

For most applications you want a variable frequency drive that has an output rating that equals or exceeds the nameplate current rating of the motor. If you base your selection on the motor horsepower rating you might get a VFD that is too small. For severe or unique applications please contact our in-house technical department.

How will using a variable frequency drive (VFD) save me money?

If you have an AC motor drive application that does not need to always run at full speed then you can reduce energy costs by controlling the motor with a variable frequency drive. VFD's allow you to match the speed of the motor to the requirements of your process. Basically variable speed drives allow you to consume less energy when your load requirements are less than full speed. Ideal in HVAC applications.

Variable speed drives also gradually ramp the motor up to operating speed which avoids abruptly starting the motor. This will reduce the stress on the motor and extend the life of the driven equipment and motor.

Take a look at Wikipedia's definition for variable frequency

When would one choose a high performance AC drive over a Phase Converter.  We first lets define what these two items are and what they are typically used for in industry.  ( Basic Definitions supplied by Wikipedia)

First; A rotary phase converter, abbreviated RPC, is an electrical machine that produces three-phase electric power from single-phase electric power. This allows three phase loads to run using generator or utility-supplied single-phase electric power.

Next; A variable-frequency drive (VFD) (also termed adjustable-frequency drive, variable-speed drive, AC drive, micro drive or inverter drive) is a type of adjustable-speed drive used in electro-mechanical drive systems to control AC motor speed and torque by varying motor input frequency and voltage.^[1][2][3][4]

These are just the simple definitions to lay some basic ground work.  But here at Marshall Wolf Automation we receive many calls where people are looking to utilize the benefits of being able to convert single phase power into 3 phase power through a drive.  While it is true that a drive can offer this conversion, it only should really be applied when trying to control a specific motor or a group of motors tied in series all taking the speed control in a master-slave arrangement. 

The rotary phase converters best application is when trying to use the item to provide general power in converting single to three phase for general use for power for all products in a facility. The primary difference being that the VFD needs a signal communication feedback from the motor to the drive to be able to "communicate" between the drive and the specific motor.  The VFD can't be used as general purpose item just to provide 3 phase power, it will not operate as intended.  In those instances "general power" its best to use a the rotary phase converter as the solution of choice. 

When it comes to VFD's Marshall Wolf Automation is your premier multi line supplier of VFD's.  We carry over 8 brands including; AC Tech Lenze, Delta Industrial Automation, Fuji, Gefran, Hitachi, Teco Westinghouse, US Drives, WEG, along with complementary accessories for the drives. 

To further discuss your requirements, please contact us at www.wolfautomation.com, or call us at 847-658-8130 or email us at sales@wolfautomation.com.

Carlo Gavazzi offers a complete range of Contactors and Overloads for switching currents up to 800 Amps. All contactors are available with a wide selection of coil voltages and come standard with built-in auxiliary outputs. Interlock and wiring kits are available to turn 2 standard contactors into reversing contactors.   In addition, our range also includes Definite Purpose Contactors up to 50 Amps in 1 pole, 1 pole + shunt, 2 pole, and 3 pole configurations. The 3 pole types can also be configured as reversing starters.   We also offer complete enclosed starters with a choice of plastic or metal housing. Starters are available with none or with a start and stop pushbutton.   Our range also includes Manual Motor Starters up to 100 Amps.

Marshall Wolf Automation is your authorized Carlo Gavazzi distributor!

• Manufactured by Carlo Gavazzi
• Motor ratings up to 75hp
  • Resistive ratings up to 140A
  • CSA elevator ratings up to 75A
• On or more auxiliary contacts on each contactors
  • Two auxiliaries on overloads
• Screw terminals are standard
  • Lug terminals offered as an option on sizes above 35 amp
• Wide range of AC and DC coil voltages
• Coils with dual terminals
• Cover for contactor test button
• Mechanical interlocks with auxiliary contacts
• Busbars for reversing contactor combinations
• Direct link and back plates for connecting contactors to manual motor starters
• 3-pole(NO) main contact
• Finger proof design
• DIN rail or screw mountable
• AC or DC control in different physical size
• UL and cUL Approved
• Accessories available, contact us for more information

When considering contactors, consider Carlo Gavazzi contactors, well built and long lasting in the industrial markets, contact Marshall Wolf Automation, your industrial automation distributor for the entire Carlo Gavazzi line.  Contact us today, we can help! Call today at 847-658-8130, or see us at www.wolfautomation.com, or email us at sales@wolfautomation.com.

A quick note that you will notice an onslaught of blogs regarding definite purpose contactors.

We recently had a very productive meeting with our Chint/Noark contacts so everyone has this subject fresh in their mind!

Definite purpose contactors are ideal for heating, air conditioning (HVAC), refrigeration and food and beverage equipment.  They have become popular for electric motors, lighting, compressors and much more. 

So what is the difference between a contactor and a starter? A manual motor starter is basically an ON-OFF switch with overload protection. A manual motor starter is a motor controller that operates from a toggle handle or push button that is operated by hand.  A contactor is an electrical switch used for switching current on and off in a circuit without overload protection.

A starter is usually an assembly, that includes a contactor plus an overload relay, used to start an electric motor.  Contactors are rated by their current in amps while starters are rated by their horsepower capacity and the current they use.  They are also generally designed for the intended life cycle of the application.

Manufactured by Chint,  these are generally easily interchangeable with other dp contactor brands including Eaton contactors, Schneider, Dayton and Furnas/Siemens. 

Contact us for any assistance cross referencing your contactors!  Marshall Wolf Automation - your one-stop factory automation distributor!  Call us today: 800-325-9653!