Here, There and in Between

You learn things when you build a car, and if it takes you long enough, you’ll learn enough to improve on your orginal plan by the time you get to the later stages. This is part, but not all, of what accounts for having to do everything three times. In our case, that is nowhere truer than in wiring up Scarlett’s LS3 416 to the FAST XFI computer and ignition box…Read More.

 

VEMP-150700-COVER

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SHIFTING PREFERENCES: Why the use of Electronic Controls is growing

The benefits of electronic controls align closely with the preferences of operators and fleet managers, as well as the OEMs and system integrators who design and build small and large vehicles. Consequently, electronic controls are increasingly used across a range of on- and off-highway vehicle applications, especially where uptime is key.

Today, there is a shift from traditional electromechanical devices to electronic Controller Area Network (CAN) technology, the most common of which is the Society of Automotive Engineers (SAE) J1939 CAN 2.0B standard for communications and diagnostics. The electronic CAN technology helps OEMs and system integrators reduce manufacturing and troubleshooting time, because of the simplification of the harness assembly, increased flexibility, and improved diagnostics capabilities. In addition, CAN technology can also improve operator feedback and overall equipment reliability, offering late-point definition capabilities, increased illumination options, and dramatic reductions in harness complexity.

Before: Total of 84 wires to controller

 vehicle body control switches

 

After: Total of 4 wires to controller

vehicle body control switches

Electronic switch modules are engineered as an alternative to traditional electromechanical switches for use with a vehicle control network. Typically, the technology is used to accomplish one or more of the following:

  • Simplify system control architecture, reducing assembly time
  • Reduce weight and potential warranty issues
  • Simplify the wire harnesses
  • Improve operator feedback
  • Increase switch life-cycle performance

Shifting preferences

Electronic vehicle network technology has been around for more than a decade. So why are preferences changing now? In large part, it is because wiring (and wiring harnesses) are becoming more and more complex as control requirements continue to increase.

Yet there are space constraints behind the dash— there are only so many switches and wires that will fit. Wire harness troubleshooting is difficult at best, and accommodating proprietary messaging structures is time-intensive and costly, compared to using the J1939 standard. Further, there are only so many points of I/O on existing controllers, and all of those points can be exhausted. Adding more points of connection is costly in terms of increasing controller size.

However, there are times when the traditional technology makes more sense. Vehicles that have relatively simple control architecture, a low volume of interface products, or those that have no intention of multiplexing their platforms, may be better served using traditional electromechanical devices. Even customers who have adopted CAN technology may still employ electromechanical solutions for specific applications, such as for a “park brake,” where direct control is preferred, or for accessories that get added after shipment.

By Robert Kitten

Program Sales Manager, Eaton

Ensuring On-going Compliance with the RoHS Directive

Fundamentally, RoHS restricts six substances: 4 heavy metals (lead, cadmium, mercury, hexavalent chromium) and two flame-retardants (PBBs and PBDEs). The concentration limits for all these substances is .1% of any homogenous material – except for cadmium (.01%). Despite the fact that RoHS only applies to electrical and electronic equipment (EEE ) placed on the EU market, it has been highly influential in pushing similar (but NOT identical) requirements in many other geographies.

RoHS has also instigated a global change in the design and composition of off-the-shelf components that affects many industries, including the equipment industry. As a result, changes in RoHS are noteworthy even for manufacturers whose products are out of scope or are sold outside the EU. In that regard, all equipment manufacturers should be aware that the key business risks to be mitigated are enforced obsolescence and design changes, as well as the loss of market access due to non-compliance.

Like most legislation, RoHS is not a static animal. It was “recast” at the beginning of 2013 and is now commonly known as RoHS2 (directive 2011/65/EU). Below are key changes between RoHS1 and RoHS2.

Substance Scope

Although the substances and their allowable concentration limits did not change between RoHS1 and RoHS2, the addition of further substances is imminent. The EU Commission is proposing to restrict four plasticizers (DEHP, BBP, DBP, DiBP) and one flame retardant (HBCDD), which has been identified as a Persistent Organic Pollutant and will be banned globally, irrespective of RoHS. All of these proposed substances are already REACH SVHCs. No timetable has been published, but the earliest any ban could take effect is probably between mid-2017 and 2019.

Furthermore, RoHS’ expansion of substance scope does not end there. An additional round of restrictions is envisioned. The most likely candidates are TBBPA (another flame retardant), MCCP (a flame retardant and plasticizer) and even PVC. Several other substances are also possibilities.

In regard to future substances, ERA Technology is currently an invited member of a working group of representatives from industry, EU Member States and NGOs. The group was formed by the European Commission to consider improvements in the methodology for identifying future substance restrictions. ERA’s main focus is establishing an approach that considers potential alternatives to substances that are proposed for restriction. This approach is meant to be even-handed and evidence-based, while taking into account the entire product life cycle.

Product Scope

The original RoHS directive focused mainly on consumer and other high volume products in 8 categories. The recast brings several other categories within scope at different times:

  • July 22, 2014 – Medical devices, Monitoring and control instruments
  • July 22, 2016 – In Vitro Diagnostics (IVD)
  • July 22, 2017 – Industrial monitoring and control instruments
  • July 22, 2019 – Other equipment (subject to review)

The first of these dates has already passed. Changing product designs and processes to meet this deadline, as well as future ones, has been the focus of intense activity.

‘Like most legislation, RoHS2 is not a static animal’

In addition, the recast has brought in a broader understanding of what constitutes EEE. Previously, many (but not all) EU Member States considered EEE to be in scope only if the product’s main function depended on electricity (Under this definition, for example, a petrol lawn mower was out of scope, even though it has a spark plug.) But now, under RoHS2, EEE includes products with any electrical function. Any product within this broadened interpretation must comply by July 22, 2019.

Note that there are other important issues regarding the impact of the above deadlines and recast product categorizations (e.g. what is “industrial”), but they are beyond the scope of this summary article.

Please review the Table

Key EU RoHS2 Compliance Dates

DATE DESCRIPTION
12/31/2014 Last date for EU Member States to implement changes to RoHS’ Exemptions List (Directives 2014/69/EU – 2014/76/EU )
4/13/2015 Exemption 4d for mercury in high pressure mercury (vapour) lamps expires
4/13/2016 Exemption 2 (b) 2 for mercury in non-linear halophosphate lamps expires
6/30/2016 Exemption 33 (Annex IV) for lead in solder on populated printed circuit boards for class Iia mobile medical devices expires
7/21/2016 Default expiration date for exemptions in Electrical and Electronic Equipment (except RoHS Categories 8 and 9), where not otherwise specified Substance restrictions extended to in vitro medical devices
7/22/2017 Substance restrictions extended to industrial monitoring and control instruments
12/31/2017 Expiration of exemption 1g for mercury in single capped CFLs <30W: 3.5 mg and exemption 28 (Annex IV) for lead in solders for mounting cadmium telluride and cadmium zinc telluride digital array detectors to printed circuit boards
12/31/2018 Expiration of exemption 4g for mercury in hand-crafted luminous discharge tubes used in certain signs and lighting; exemption 41 for lead in solders and termination finishes of components and circuit boards in ignition modules and other engine control systems; and exemption 37 (Annex IV) for Category 8 and 9 exemptions for lead in platinized platinum electrodes for conductivity measurements
7/22/2019 Substance restrictions expanded to category 11 (other EEE not otherwise exempt) – open scope
12/31/2019 Certain exemptions (24, 30, 32 and 38) for Categories 8 and 9 will expire
6/30/2020 Exemption 27 (Annex IV) for lead in solders, coating and connections in certain medical devices expires
12/31/2020 Expiration of exemptions 33 (Annex IV) for lead in solder on populated printed circuit boards for class IIb mobile medical devices; for lead in other than C-press compliant pin connector systems for industrial monitoring and control instruments; and for lead in dielectric ceramic in capacitors for industrial monitoring and control instruments.
6/30/2021 Certain exemptions (12, 22, 23, 25, 26 and 29) for Categories 8 and 9 will expire
7/21/2021 Expiration of exemption 31 for lead, cadmium and hexavalent chromium in reused spare parts recovered from medical devices in closed loop lead in micro-channel plates in medical devices and monitoring and control instruments; systems; exemption 39 (Annex IV) for and exemption 34 (Annex IV) lead as an activator in fluorescent powder of some discharge lamps
7/21/2023 Exemption 39 (Annex IV) for lead in micro-channel plates in in-vitro medical devices expires
7/21/2024 Expiration of exemption 39 (Annex IV) for lead in micro-channel plates in industrial monitoring and control instruments, as well as exemption 35 (Annex IV) for mercury in cold cathode fluorescent lamps in certain liquid crystal displays in industrial monitoring and control instruments

 

Robertson, Chris. “Ensuring On-going Compliance with the RoHs Directive.” ERA Technology.

 

IP Code

The IP Code, International Protection Marking, IEC standard 60529, sometimes interpreted as Ingress Protection Marking, classifies and rates the degree of protection provided against intrusion, dust, accidental contact, and water by mechanical casings and electrical enclosures.

The standard aims to provide users more detailed information than vague marketing terms such as waterproof. Two numbers indicate protection against solid bodies, first digit, and against liquids, second digit, in accordance with the charts below.

Ingress Protection Rating Guide

First Number | Effective Against

0
  • No protection (Sometimes X)
1
  • Protected against solid objects up to 50mm3
2
  • Protected against solid objects up to 12mm3
3
  • Protected against solid objects up to 2.5mm3
4
  • Protected against solid objects up to 1mm3
5
  • Protected against dust, limited ingress (no harmful deposit)
6
  • Totally protected against dust

Second Number | Effective Against

0
  • No protection (Sometimes X)
1
  • Protection against vertically falling drops of water (e.g. condensation)
2
  • Protection against direct sprays of water up to 15 degrees from vertical
3
  • Protection against direct sprays of water up to 60 degrees from vertical
4
  • Protection against water sprayed from all directions – limited ingress permitted
5
  • Protected against low pressure jets of water from all directions – limited ingress permitted
6
  • Protected against low pressure jets of water, limited ingress permitted (e.g. ship deck)
7
  • Protected against the effect of immersion between 15cm and 1m
8
  • Protected against long periods of immersion under pressure

Ingress Protection Rating Guide

Waytek Adds High-Demand GIGAVAC Rugged Environment Products to Its In-Stock Selection of OEM Electrical Components

Waytek, Inc., a leading distributor of electrical wiring supplies, connectors, and relays for electrical systems in the mobile equipment markets, is pleased to announce the addition of GIGAVAC rugged environment products to its broad, in-stock, offering of OEM electrical components.

GIGAVAC manufactures advanced switching solutions including high voltage relays, Waytek GIGAVAC press release imagecontactors, manual disconnect switches and other power products. Waytek customers can now order GIGAVAC’s most popular parts directly through Waytek.

GIGAVAC products are hermetically sealed—airtight and waterproof—so there is no corrosion. Parts are designed and manufactured for extreme environments (humidity, submersion, dust, high temperature, heavy shock and vibration). GIGAVAC construction allows for very long life cycles, and low warranty and service costs.

Waytek carries GIGAVAC’s most popular parts including a series of chassis mount contactors up to 600A, and 300A and 500A Battery Disconnects. Each heavy-duty contactor is ceramic to metal brazed, gas filled hermetically in a sealed chamber to protect key components, exceeds IP69K standards, and is temperature tested to 200 degrees Celsius.

“We have many customers that specialize in heavy-duty commercial, military, mining, agricultural and construction equipment. Being able to provide them with airtight and waterproof equipment allows Waytek customers to source from fewer suppliers,” said Jim Keister, marketing manager at Waytek, Inc.

About Waytek: Since 1970, Waytek has been providing electrical wiring supplies to OEMs in the truck body and trailer, construction machinery and equipment, mining, agricultural equipment, and emergency vehicle markets. Waytek maintains a large inventory of more than 10,000 different electrical supplies. Waytek prides itself on having the “Right Parts, In Stock, to be delivered On Time.” To view GIGAVAC products, visit the Waytek website at www.waytekwire.com

About GIGAVAC: Based in Santa Barbara, California, GIGAVAC manufactures and distributes Advanced Switching Solutions. GIGAVAC’s sealed switching devices include high voltage relays, contactors, manual disconnect switches and other Power Products. Used in a wide variety of applications, typical customers are manufacturers of commercial and military vehicles, as well as boats, light rail, mining, factory automation power systems, battery charging and management systems, fuel cells, solar and wind power systems, test equipment, HV power supplies, wafer fabrication, RF communications equipment, MRI/medical equipment and others in need of Advanced Switching Solutions. www.GIGAVAC.com.

 

Overcurrent: Eliminate the Hazards

When considering the generic application for circuit protection within the confines of appliance or equipment design, there are three significant categories of consideration.

They are:

1) Avoidance of hazardous conditions for operating personnel and others indirectly involved.

2) Any reduction in size of current-carrying conductors.

3) Isolating a faulted function—leaving the normally operating functions able to continue.

The safety issue is undoubtedly the most important of these three. The primary safety focus is to eliminate two types of hazards:

1) Electrical shock

2) Smoke and fire

The safety consideration manifests itself most often in the primary-input circuit protector. In this application, power enters the appliance and is immediately met by a protector that is ready to take the system off-line when required.

The matter of current reduction is really a traditional definition for circuit protection application. Anywhere there is a reduction in the size of a current-carrying medium; the potential exists for a fault to exceed the limits of that medium. For example, wire is designed to carry 20 amps, and is protected accordingly. If a branch circuit is taken from this 20-amp circuit utilizing wire (which, depending upon insulation, is rated to carry 3 amps), then a dangerous overload in the 3-amp circuit (say, 15 amps or a 500% overload) would not be noticed by the 20-amp circuit. (Figure 1)

Figure 1

Figure 1

The third issue involves the design of fault-tolerant equipment and relates to the case illustrated above involving distributed power through branch circuits (Figure 1). If the low-amp branch circuits are independent functions, a fault in one circuit should not take the whole system down. By inserting a circuit breaker in each of the branches, the fault is isolated to the least-affected circuit, leaving the others to function normally.

Types of Abnormal Conditions

In the discussion of circuit protection, it is convenient to separate fault conditions into two types. They are distinguished by virtue of their magnitude, but also by their cause-and effect relationship. The two are overload and short circuit. MP_Circuit Breaker Group

An overload is a condition where, for various reasons, the current level within an electric circuit exceeds its specified limits but continues along its designed path. An excellent example is a stalled motor. This situation, at least initially, exceeds the normally specified steady-state condition. Overload will occur at start-up, or if the rotation of the motor is impeded in some way.

This overload will generally be in the area of 300–700% of the rated current level of the device. Start-up conditions are allowed for within most circuit designs. Other extended overload conditions must be protected.

Short circuits, on the other hand, are conditions that occur when the current path to the load is bypassed with a very low or negligible resistance path. Under this condition, excessively high current flows, which represent a significant hazard both to the appliance and attendant personnel.

In general, an overload is defined by a magnitude of 200–800% of normal rating, and a short circuit is anything greater than this. Because of its limited impedance/resistance path, however, a short circuit is usually considerably higher than 1000% of normal rating. A short circuit involves circuit damage. An overload may or may not involve circuit damage and many times is easily eliminated without repair, even though sustained overloads result in short circuits over time if not protected.

Automotive Wire Gauge Guide

Automotive-Wire-On-ShelfThe automotive wiring you select for manufacturing and maintaining vehicles and equipment is an integral part to keeping electrical systems reliable. Not only is the type of wire you select important, like automotive gpt primary wire or automotive cross-link wire, but it’s also important to choose the best automotive wire gauge size based on your application current draw, potential electrical resistance and voltage drop.

Voltage Drop & Automotive Wire Gauge Guide
Voltage drop is the amount of voltage lost over the length of the automotive wire or cable. Voltage drop changes as a function of the resistance of the wire and should be less than 2% if possible. If the drop is greater than 2%, efficiency of the equipment in the circuit is severely decreased and life of the equipment will be decreased.  As automotive wire lengths get longer, electrical resistance builds up until it forces the voltage down below a usable level. At that point, up-sizing the wire gauge will restore the voltage to its intended level.

Voltage drop can be calculated using Ohm’s Law: Voltage Drop = current in amperes x resistance in ohms. 

For a more convenient calculation, voltage drop calculators and automotive wire gauge guides, like the chart shown below, can be helpful reference tools. This wire gauge guide shows the maximum run of wire that is recommended for 22 through 4/0 automotive wire gauges based on different current draw ratings.

Wire-Gauge-Guide

Disclaimer: Many factors can affect the performance of the application, such as voltage, temperature, load, etc. With so many variables, Waytek is providing this wire gauge guide as a general guideline only. Please refer to your design engineer for final decisions.

Simplified Wiring

DiagramMultiplexing is a technique that can simplify your wiring. In traditional systems, the wires run from each switch to the device they power. In a multiplexed system, a module containing at least one microprocessor consolidates inputs and outputs for an area of the vehicle. With more and more devices in vehicles each year, multiplexing is necessary to keep the wiring from getting out of control.  In a multiplexed system, a module containing at least one microprocessor consolidates inputs and outputs for an area of the vehicle.

Output PDM

For instance, vehicles that have lots of controls on the door may have a driver’s-door module. Some vehicles have power-windows, power-mirrors, power-locks and even power-seat controls on the door. It would be impractical to run the thick bundle of wires that would come from a system like this out of the door. Instead, the driver’s-door module monitors all of the switches.

Here’s how it works: If the driver presses his window switch, the door module closes a relay that provides power to the window motor. If the driver presses the switch to adjust the passenger-side mirror, the driver’s door module sends a packet of data onto the communication bus of the car. This packet tells a different module to energize one of the power-mirror motors. In this way, most of the signals that leave the driver’s door are consolidated onto the two wires that form the communication bus.

Nice, Karim. “How Car Computers Work.” howstuffworks.com.

Copper Tumbles to Lowest in More Than 5 Years, Oil Rout Weighs

LONDON, Jan 12 (Reuters) – Copper prices slid to their lowest in more than five years on Monday as further weakness in oil kept commodity markets under pressure, investors worried about excess supplies and speculators kept up their selling.

Three-month copper on the London Metal Exchange (LME) dropped to a session low Wire of $5,966 a tonne, its weakest since October 2009, as sell orders kicked in at preset price levels, traders said.

Copper – which shed 14 percent in 2014 and is down nearly 5 percent already this year – closed 1 percent weaker at $6,015.50.

With market data showing an increase in bearish bets against copper, the metal was caught in a commodities downdraft spurred by oil, which dropped below $48 a barrel as Goldman Sachs slashed its short-term forecasts and Gulf producers showed no signs of cutting production.

“The weakness we are seeing is part of the ongoing deleveraging out of commodities. We have seen that in oil and also in the likes of iron ore and coal. It seems there is greater supply compared to demand and that is also the case for copper,” said Robin Bhar, an analyst at Societe Generale.

Bhar said he sees $5,500 a tonne as a bottoming-out level for copper.

Analysts polled in October had expected the copper market surplus to rise to 350,000 tonnes this year from a forecast 94,300 tonnes in 2014.

Copper traders had been eyeing two big put-option trades at $6,000 and $5,500 per tonne, which they fear could accelerate the market’s longest rout in years as prices sink to their lowest since 2010.

Hedge funds and money managers increased bearish bets in copper contracts during the week to Jan. 6, U.S. Commodity Futures Trading Commission (CFTC) data showed on Friday.

Aluminium closed down 0.4 percent at $1,810 a tonne.

“We note that reported inventories continue to fall, suggesting that World ex-China remains in deficit,” said metals strategist Michael Widmer at Bank of America Merrill Lynch.

LME aluminium stocks MALSTX-TOTAL fell 9,775 tonnes on Monday.

“We expect the aluminium market in World ex-China to remain undersupplied also in 2015, suggesting that prices will remain supported,” Widmer added in a note.

Zinc closed down 1.1 percent at $2,138 a tonne, lead gained 1.5 percent to $1,867, nickel ended down 2.6 percent at $15,100 a tonne and tin added 1.3 percent to $19,900.

Bahl, Harpreet. “Copper tumbles to lowest in more than 5 years, oil rout weighs.” Reuters.com. January 12, 2015

Current Copper Pricing

(click here to view our wire)

Everything You Need to Know About Tier 4 Final

New diesel engines will be cleaner than ever, the results of a decade long evolution in technology.

January 1, 2014, was a bellwether day for off-road diesel engines. On that date, the majority of diesel engines sold in the United States, Japan and most of Europe met the most strict exhaust emissions standards yet.

To meet those standards – called Tier 4 Final in the U.S. – manufacturers will outfit these engines with a variety of new exhaust aftertreatment components. The ramp up to this point has been gradual, with the Tier 3 standards phased in between 2006 and 2008, Tier 4 Interim from 2008 to 2012 and now Tier 4 Final.

You won’t have to deal with the full gamut of Tier 4 Final technology until you buy your next new piece of equipment or new engine. But eventually almost everybody will have some Tier 4 Final machines in their fleet. And many of you have at least some Tier 3 or Tier 4 Interim machines in your fleet now. There are even some engines out currently that meet Tier 4 Final requirements.

The reduction in emissions from diesel engines as a result of this technology has been nothing short of astounding. But it is mandated by the EPA, and it doesn’t come cheap. By some estimates, the new engines have boosted machine prices by as much as 10 percent.

Here’s a short review to help you sort out all the details:

EMISSIONS

The EPA regulations aimed to drastically reduce two primary exhaust pollutants. Particulate matter, or PM, is mostly unburned hydrocarbons like soot that previously shot out the exhaust stack unimpeded, and nitrates of oxygen or NOx, which is a primary ingredient of smog.

EGR

With the advent of Tier 3 regulations, most manufacturers added an exhaust gas recirculation – or EGR – circuit to their engines. EGR takes a portion of the exhaust gas and recirculates it with fresh intake air. The exhaust air reduces the amount of oxygen in the combustion chamber. When this oxygen-reduced air ignites on the compression stroke, the resulting exhaust contains less NOx. Tier4Side1The EGR circuit is a simple fix. There is an EGR valve, controlled by the engine’s electronic control module, but otherwise it’s simple plumbing. Recirculating hot exhaust gas back into the engine increases temperatures. So most EGR engines run the recirculated exhaust gas through a cooler. Some manufacturers also increased their engines’ overall cooling system sizes as well.

DPF

To bring down PM to acceptable levels in high horsepower Tier 3 engines most manufacturers resorted to using a diesel particulate filter, or DPF. These large, honeycombed, ceramic filters are coated with precious metal catalysts that trap PM in the exhaust stream.

In normal operating conditions, the exhaust temps are hot enough to incinerate most of the trapped PM in a DOC. But idling, cold starts and light load factors can accelerate PM accumulation. When a DPF becomes full enough to affect backpressure, the engine’s ECM injects a stream of diesel fuel into the DPF, raising temperatures and burning off the accumulated PM. This is called regeneration.

On some systems regeneration happens automatically without the operator needing to do anything. On others, a warning light comes on to let the operator know that he needs to activate the regeneration system. Regeneration temporarily raises the exhaust temperatures, making it important not to engage in a regeneration cycle when you’re around combustible material.

Eventually ash, which won’t burn off, collects in the DPF, requiring it to be cleaned or exchanged. The EPA requires manufacturers to size DPFs on engines 175 horsepower and up to last at least 4,500 hours between cleanings. For engines below 175 horsepower, the required maintenance interval was set at 3,000 hours.

Most heavy equipment manufacturers today offer guaranteed intervals on DPF replacement or cleaning. To prevent excessive ash buildup and possibly voiding your warranty, use a low-ash oil. These are typically designated with an American Petroleum Institute’s CJ-4 label.

Be mindful that DPFs are so good at scrubbing soot from your exhaust that they can take away the visible smoke that used to tell you of impending engine problems. DPFs can also be compromised by over extended drain intervals, faulty fuel injectors or cooling system problems so it’s important to keep the entire engine well tuned and in top shape.

DOC

Another way manufacturers are reducing exhaust pollutants is the used of diesel oxidation catalysts. These are filters with a catalytic coating on the filter media. Much like the catalytic converter in a car, the catalyst on a DOC chemically changes carbon monoxide, hydrocarbons, diesel particulates and other pollutants to carbon dioxide and water.

In some engines a DOC is used in conjunction with a DPF. In many lower horsepower engines a DOC is sufficient to meet Tier 4 Final regulations without the need for a DPF. These are often touted as “maintenance free” since most stand-alone DOCs do not need cleaning or replacement and are warranted for the life of an engine.

SCR

Tier 4 Final regulations called for a drastic cut in NOx levels. In most engines this was more than EGR alone could handle. The solution was to install a new exhaust after treatment system called selective catalytic reduction, or SCR.

In an SCR system, the exhaust passes through a DPF or DPF/DOC combination first and is then doused with a mist of water and urea (a common chemical used in commercial fertilizers) in a catalytic chamber. The urea/water solution is commonly referred to as diesel exhaust fluid, or DEF. The exhaust and DEF in the presence of the catalyst turns the NOx into mostly water and nitrogen.

Since 2010, on-road trucks have used SCR to reduce NOx, so the technology is well proven. It does add another layer of complexity, but there are several advantages. For one, the use of SCR means the engine can meet emissions standards with a less aggressive use of EGR – so these engines run cooler.

The disadvantages of SCR are that you have to keep DEF in stock and refuel the DEF tanks on your equipment. If you run out of DEF, the engines are programmed to derate, eventually to the point where you can no longer operate. Running out of DEF is just as disruptive to your operations as running out of diesel.

DEF consumption ranges from 3 to 6 percent of your diesel fuel consumption. But since DEF is priced at or lower than diesel fuel and since it actually helps improve fuel economy, most view the pricing issue as a wash.

ULSD

Ultra low sulfur diesel was introduced into the marketplace in 2009 and 2010. The sulfur levels were reduced because the catalysts used in DOCs and SCR could not handle the higher levels of sulfur.

As an equipment owner or manager, you don’t have to worry about mis-fueling your machines, at least in the United States and Canada. Today ULSD is the only type of diesel you can buy. But the fact that the newer engines can only burn this specific type of diesel may affect the resale value of these machines in the future.

Most auction companies say up to half of the machines they sell wind up going overseas, many to Latin America. In these countries, and most of the rest of the developing world, ULSD is not yet available. So some are predicting a glut of Tier 4 Interim and Final machines in the market in the future, which could depress prices for emissions-compliant used equipment.

Most manufacturers are working on a “de-tiering” solution, a modification that would allow these machines to operate using the higher sulfur fuel. But this process is still in the early stages and the details of how this will be accomplished differ between manufacturers.

If you’re a fleet manager with a big fleet and a regular turnover schedule, talk to your OEM or equipment dealer about their de-tiering solutions before determining the equipment’s residual value.

Additional

As the technology of diesel engines has progressed from Tier 3 to Tier 4 Final other aspects of the engines have been tweaked as well. To provide better fuel combustion and throttle response manufacturers have fine tuned the fuel-air mixtures with a variety of turbocharger designs such as twin turbochargers (a large and a small one) and variable geometry turbochargers. Fuel systems have largely gone to a high pressure, common rail design with pressures as high as 30,000 psi or more. And electronic engine control modules have allowed for ultra-high speed, ultra-precise fuel injection sequences.

The bottom line is that new diesel engines are cleaner than ever before, and in many cases more fuel efficient, too. But along with this comes the need to properly price these more expensive engines and any additional maintenance into your equipment owning and operating costs and to make sure any new maintenance protocols are in order to avoid surprises and maximize uptime.

Jackson, Tom. “Everything You Need to Know About Tier 4 Final.” Equipment World. 10/01/2013

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