Mechanical Products, a manufacturer of High Quality Thermal Circuit Breakers will be exhibiting at the NTEA Work Truck Show, in Indianapolis, Indiana

March 4 through March 6, 2015

Visit us in Booth # 5084

See all our NEW Product Introductions

Series 12 - Series 15 - Series 17 Hi-Amp Circuit Breakers

NEW tripID^TM Lighted Hi-Amp Accessory

And Other New Re-Engineered Truck Circuit Protection Products

Mechanical Products Company, 1112 N. Garfield Street, Lombard, Illinois 60148

Phone:  630-953-4100 -- Email:  helpme@mechprod.com

Visit our website at www.mechprod.com

MECHANICAL PRODUCTS ANNOUNCES ANOTHER

NEW FAMILY OF CIRCUIT BREAKERS:

THE SERIES 15 PUSH-TO-RESET

Available in Amp ratings from 3 to 40 Amps, the NEW 15 Series offers an economical, compact design in single pole circuit protection.  Offering the same small package size from 3 to 40 amps will make panel installation designs much easier, efficient and cost effective.  All Series 15 Thermal Circuit Breakers have a rated voltage of 125/250VAC, 50 VDC with an Interrupt Capacity of 1000A and a Dielectric Strength of 1500 VAC.  They are ROHS Compliant, UL1077, CSA Approved and UL1500 Ignition Protected. VDE and CCC certification is curently Pending.

The MP 15 Series is designed for various applications:  Marine, Household Appliances, Power Strips, Lab Furniture, Audio Visual Equipment and more.  Qualified for resistive and motor load applications, they are ideal for Marine Panels, Transportation, Floor Care and other motor start up applications.  The 15 Series Thermal Circuit Breakers are available in various threaded and snap-in bushings, along with multiple Quick Connect and Screw Terminal styles to meet nearly every installation requirement. 

MP has been a leading designer and supplier of thermal circuit protection since 1943.  MP circuit breakers are used in thousands of commercial and industrial applications ranging from medical equipment, appliances, lighting and communication devices, to marine, recreational and off road vehicles/equipment, and electrical protection devices.  MP has been management owned and operated since 1998, is headquartered in Lombard, Illinois and maintains manufacturing capabilities in the US and overseas.  For additional information, visit our website at www.mechprod.com.

Mechanical Products, a manufacturer of High Quality Marine Circuit Breakers will be exhibiting at the IBEX - 2014 Marine Trade Show, in Tampa, Florida

September 30 through October 2, 2014

See all our NEW Product Introductions

Series 12 - Series 15 - Series 17 Circuit Breakers

Mechanical Products Company, 1112 N. Garfield Street, Lombard, Illinois 60148

Phone:  630-953-4100 -- Email:  helpme@mechprod.com

Visit our website at www.mechprod.com

NEW 17 SERIES THERMAL

CIRCUIT BREAKERS

Standard designs, New Side-By-Side Surface and Easy Access 90^o Panel Mount

Available in 25 to 200 Amp Ratings

Mechanical Products (MP) announces the release of the Series 17, which is designed for industrial transportation and vehicle accessory manufacturers to include Agricultural, Construction, Marine, Bus, Emergency Vehicles, Automotive Lifts, Battery Chargers, Recreational Vehicles and Trucks.  The Series 17, manufactured in the U.S.A., is a main or branch circuit breaker used in accessory or auxiliary direct circuit (DC) electrical systems operating in harsh environments to provide protection in the event of overload and, or short circuit interruptions.  The Series 17 is offered in 25 to 200 amps and is specifically designed with features including new mounting configurations and termination styles.  The Series 17 is available in the second quarter of 2014 through MP’s authorized distribution partners.

The Series 17 offers end users and designers improved access to wiring and operation, corrosion resistant studs and hardware, superior moisture sealing, a variety of mounting options, higher amperage ratings, and potential use of bus bars while enclosed in a durable, sealed thermoplastic housing.  The Series 17 is compatible to existing mounting profiles while offering new features and mounting styles that allow for next generation designs. 

The MP Series 17 offers NEW Side by Side Surface and Easy Access 90^o Panel Mount designs, in addition to standard mounting profiles.  Surface Mount configurations are available in 1/4” and 3/8” heavy duty stainless steel terminal studs.  Panel Mount units are available with 1/4” brass, nickel plated terminal studs.  All are available in 25 to 200 amp ratings with stainless steel terminal sems nuts as an option.  Priced competitively, these high quality breakers, commonly known as High Amp circuit breakers or Hi Amp circuit breakers, are assembled right here in the USA, with minimal lead time required.

MP has been a leading supplier of thermal circuit protection since 1943.  MP circuit breakers are used in thousands of commercial and industrial applications ranging from medical equipment, appliances, lighting, and communication devices, to recreational and off road vehicles/equipment, and electrical protection devices.  MP has been management owned and operated since 1998, is headquartered in Lombard, Illinois and maintains manufacturing capabilities in the US and overseas.

For additional information on these and other high quality MP thermal circuit protection devices, visit Mechanical Products at www.mechprod.com.

Mechanical Products, a manufacturer of High Quality Circuit Protection Devices will be exhibiting at the CONEXPO/CONAGG SHOW,  in Las Vegas

March 4 -8, 2014

See all of our New Product Introductions

Mechanical Products, 1112 Garfield Street, Lombard, Illinois 60148

Phone:  630-953-4100 -- Email: helpme@mechprod.com

Visit our Website at www.mechprod.com

MECHANICAL PRODUCTS UL1077 SERIES 12 THERMAL CIRCUIT BREAKER

THE SERIES 12 PUSH-TO-RESET 

Available in ratings from 3 to 20 Amps, the Series 12 offers a very economical, compact design in single pole circuit protection.  The Series 12 Thermal Circuit Breakers have a rated voltage of 125/250VAC, 50 VDC with an Interrupt Capacity of 1000 A and a Dielectric Strength of 1500 VAC.  All are ROHS Compliant and UL1077 approved, with many amp ratings having CSA, CCC and VDE approvals as well.

 The MP 12 Series is designed for various applications: Marine, Household Appliances, Power Strips, Audio Visual Equipment, and more.   Various threaded and snap-in bushings, along with multiple Quick Connect terminal styles are available.   The 12 Series thermal circuit breakers are the choice where space and price are vital to the application.    For additional information on these and other high quality MP thermal circuit protection devices, visit Mechanical Products at www.mechprod.com

MP has been a leading supplier of thermal circuit protection since 1943.  MP circuit breakers are used in thousands of commercial and industrial applications ranging from medical equipment, appliances, lighting and communication devices, to recreational and off road vehicles/equipment, and electrical protection devices.  MP has been management owned and operated since 1998, is headquartered in Lombard, Illinois and maintains manufacturing capabilities in the US and overseas. 

We show in Figure 5.15a the complete steady-state DC solution for a flat arc heat flux potential with arc current I = 10i_o.

 In Figure 5.15A we also show a simple one term approximation solution  

Where the mid-plasma space magnitude S_m is given by the exact value (See Equation 5.32)

As is evident, this one term solution is an excellent approximation for the exact solution, given by (5.13) and (5.21) for this relatively high level of current drive.

Now consider the low current drive exact, and approximate solution for I = 0.1i_o given in Figure 5.15b.  Here we see that the one term approximate solution overestimates the plasma region width by a factor of

But when considered as a fraction of the total interwall space this overestimate is only 14%.

Figure 5.16 illustrates a summary comparison of the exact and approximate solutions for the plasma region halfwidth as a function of plasma steady-state current.  The worst case overestimate is seen to occur near the i/i_o = 0.1 drive point.  And here, as stated above, it is only a 14% overestimate.  The approximate solution for the heat flux potential given by Equations 5.33 and 5.34 is thus seen to be a “safe” or conservative estimate for the spatial variation of the heat flux potential of the actual flat arc.  We will use this one term approximation as the basis for a simplified dynamic arc model.

The one term transient solution for a step driven change in the heat-flux potential is taken from (5.30).

where the initial state magnitude S_mo and the final state magnitude S_mf are determined from the initial and final steady-state currents and (5.34).  The single arc thermal time constant τ is given by

The transient value of the plasma region halfwidth x_i is the x_i root of

which, in closed form, is

The transient current electric field relationship is given by

where

Performance Equations 5.35 through 5.40 are ideally suited for numerical analysis since they are based on stepwise change which, in an incremental sense, is the basis for all numerical solution techniques.  For example, assume that a flat arc is driven by a sinusoidal current source.  We approximate the continuous drive current by a stepped, discrete, staircase current, such as that shown in Figure 5.17. 

At the end of each step we solve for the resultant new electric field E(t) and plasma region halfwidth x_i using (5.35), (5.38), (5.39) and (5.40).  We then reassign these values as initial values for the next time step and repeat the solution process.  Typical results are shown in Figures 5.18 through 5.20 for ratios of arc thermal time constant τ to drive frequency period T, τ/T = 1.0, 0.1 and 0.01.

In these current driven results we note particularly the collapse of the arc, as indicated by the halfwidth x_i, as the current goes through a zero crossing.  For a given drive frequency period T, we see that the arc collapse tends to follow the current zero crossing very closely for “fast” time constant arcs (i.e. τ<<T).  But for “slow” time constant arcs (i.e. when τ is comparable to T), the arc collapse is incomplete and lags behind the current zero crossing.

In terms of practical circuit breaker design, we desire fast time constant arcs.  Fast arcs will fully collapse at a current zero crossing and thus not be subject to thermal reignition when the arc contact voltage redevelops.  From the arc thermal time constant expression (5.36), we see that in order to obtain a fast arc we need only confine the arc in narrow arc channels.  The arc time constant is seen to vary as the square of the channel width.  To confirm this theoretical prediction, Frind [5.11] conducted careful measurements of the time constants of flat arcs using the apparatus shown in Figure 5.21. 

The results of Frind’s measurements are shown in Figure 5.22. 

The dotted straight line in Figure 5.22 indicates adependency rather than the theoretical square relationship.  However in view of the inability to hold the channel walls at a constant temperature and the rough approximations that were made in deriving (5.36), the agreement can be considered to be quite satisfactory.  At very small channel widths, near 20 mils, the measured time constant were extremely fast, approximately 0.1 μsec.  This encouraging result alone, not withstanding our theory, suggests the advisability of arc confinement in cool arc channels.