Published Articles

Designing a Safe Reefer Connection: Part 1

Erika Thorson

Safe reefer operations require a receptacle system that exceeds minimum standards in electrical codes.

Designing a safe connection - part 1

Safely connecting and disconnecting reefer containers operating on 3 Phase 440-480v power represents one of the largest safety risks from an electrical hazard at the majority of container terminals. Reefer receptacles are designed and listed to electrical safety standards of UL and CE self-certification, but these only “certify” that the receptacle can carry the required electrical load. Other standards, such as IEC 60309-1 and 60309-2 cover configurations of the plug and receptacle and ensure compatibility. It is widely accepted that dealing with 480v, 32A supply presents a safety (and liability) risk and that the standard is to have interlocked connections. A safety interlock is a mechanical or electrical device that prevents a receptacle from being energized unless the male plug is properly engaged and disconnects the power supply automatically as the plug is removed. Although the safety interlock design prevents operators from “making” or “breaking” under load, it is not required under electrical codes and in some cases, terminal construction contractors look to install non-interlocked receptacles, which pose a higher safety risk to operators, but offer cost savings. Some situations arise where contractors facing strict budgets try to install non-interlocked receptacles. The objective is to make sure interlocked receptacles rather than “complying” receptacles are specified when projects are tendered. As far as the design of the interlock is concerned, there are several options. ESL’s standard system detects the ground pin of the male plug before allowing the unit to be energized, whereas other designs interlock off the key on the side of the plug. ESL believes the ground pin is the safer option. Additionally, in some markets, plug keys are frequently “shaved off” to allow a 32A plug to mate with a 30A (non-interlocking) receptacle, meaning the 32A male plug must be replaced elsewhere in the supply chain in order to safely connect to a receptacle that interlocks at the key.

Operating Efficiently

Another important aspect of reefer power supply is designing the receptacle system so the terminal can perform reefer operations efficiently. In considering the layout of the reefer area(s), terminal management has to weigh the initial costs of installing more reefer outlet assemblies (ROAs) against the labor costs of managing cabling from fewer centralized ROAs. A reefer rack structure is typically six or seven containers wide and some operators opt for an ROA with six or seven receptacles mounted centrally. This configuration is more prone to tangled reefer cables, which present tripping hazards and the chance of disconnecting the wrong cable. Terminals with wider reefer racks may even require extension cables to reach the outer containers. Installing more receptacles per ROA is ultimately a cheaper solution, but a trend towards two and three-gang ROAs due to operational efficiencies is growing. Demand is also increasing for two LED lights, one to indicate line power is available to the ROA and a second to show that the receptacle is energized and power is flowing. If the first LED is not showing, the operator will know immediately that there is an upstream power supply problem. An available option is the incorporation of an equipment ground fault protection (GFP) device on an outlet module to isolate the effect of a phase to ground short. ESL has frequently been asked to incorporate a simple ground fault protection device that can isolate a fault at the receptacle and prevent upstream switch gear from being tripped by a short. Terminal design engineers need to take into account that reefers generate ground currents during the defrost cycle, so the GFP devices should be selected and set at a value above the defrost cycle ground currents to avoid nuisance tripping.

Read part 2 of our series  focusing on reefer receptacle safety and damage control.

Power U: As Utility Power Outages Rise, 3 Universities Keep Emergency Backup Costs Down

Erika Thorson

 

ESL Emergency Power Case Study Image

Emergency Backup Case Study

May 2019

Client Profiles

Auburn University

Built in 1969, the Haley Center at Auburn University is home to the College of Education classrooms, bookstore, administrative offices, computer labs, and a dining hall. As the tallest building on campus, it has a labyrinth of corridors that regularly confuse new students. It houses the main power source and backup generator for campus-wide life-safety systems. Because of this, the system and its backup generator must be tested regularly.

“At Auburn University, options for temporarily shutting down power can be limited. Sometimes it’s hard to schedule an outage because it affects so many people due to the critical nature of the building’s services and functions. That’s why AU needs a way to load bank or test an emergency backup generator quickly and efficiently, with minimal downtime.”

– Adam Mills, Project Engineer
    Mills-Conoly Engineering
    Montgomery, Ala.

A New Hampshire college

A New Hampshire college distributes its own power to select campus areas, including its renovated, main dining commons. The institution’s engineering and utilities team recently installed a large, new backup generator at the facility. The engineers know that in order to comply with NEC 2017 700.3(F) the system must include a provision to connect a portable backup generator.

“We test our generators under load weekly – which is more frequently than code requires. Some of our generators aren’t loaded adequately, and some don’t have an MTS installed. When we bring in a portable generator or load bank, at times we have to tear apart the wiring to hard-connect the portable unit, which means we have to close the building because emergency backup power isn’t available during maintenance. It’d be a lot easier if we’d install transfer switches that allow us to switch to and from temporary equipment.”

– Laura A. Black, Electrical Engineer
    Hanover, N.H.

A leading North Carolina university

The fuel pump failed on a permanent backup generator at a public television center for a leading North Carolina university. Fixing it meant leaving the facility without backup power in the event of an emergency. Before starting the repair, engineers looked for a better way to hook up a backup generator during future emergencies and discovered this also meant installing a manual transfer switch.

“We like to spec backup-power products that are straightforward and easy for our clients to use. Equipment needs to be clearly marked and require minimal training to operate. It’s important to us because, when there’s an outage, we don’t want to leave users searching for a manual in the dark to get the power back on.”

– Addison M. Dee, PE, Electrical Project Engineer
    McKim & Creed, Inc.
    Raleigh, N.C.

Choices

Permanent or portable? The growing challenge of backup power generation at higher-education institutions

As centers of both education and community life, colleges and universities are challenged with meeting the needs of a diverse range of people and activities. From student housing and dining to classrooms and administrative offices, sports arenas and arts venues, medical facilities and research labs, assuring reliable backup power in the event of an emergency or outage is of paramount concern. The challenge becomes even greater when considering aging infrastructure, the rise of traditional and non-traditional students, and the emergence of extreme weather patterns that have led to an increase in power outages across the U.S.[1]

Guaranteeing uninterruptible backup power by installing a permanent generator and ATS, which are required for certain mission-critical applications and life-safety systems, requires costly, ongoing, special testing and maintenance. This is why many engineers specify provisions for quick connection of a load-bank testing unit and/or portable generator. The goal is to ensure standby systems are always ready and comply with regulatory testing requirements.

When making a decision about the best type of backup-power system for non-critical applications, where instantaneous power restoration isn’t required, the high cost and space requirements of a permanent generator often make portable power generation the best choice.

University challenges

  • Ensuring the safety and well-being of large numbers of academic and community users in a diverse range of operating facilities and situations
  • The expense and logistics of installing a permanent backup generator and automatic-transfer switch
  • Providing backup power to a permanent generator while down for maintenance or repair
  • Disruptions to campus life caused by outages when testing or servicing a permanent generator
  • Complying with NEC 2017 700.3(F), which requires built-in, temporary power-connection capabilities for an emergency system that relies on a single, alternate power source while the alternate source is disabled for maintenance or repair
  • Needing an electrician to switch from utility power to backup, and vice versa, to reduce the risk of back feeding or cross-connecting power sources
  • Time-consuming and inefficient rewiring to accommodate a portable load bank
  • Wet stacking and diesel-engine failure caused by repeated, insufficient loads while routinely exercising a permanent generator
  • Confusion as users rush to restore power when the lights are out

Solutions

Auburn University: Ensuring backup power to the life-safety system

Mills-Conoly Engineering is a professional engineering consultant to Auburn University. All four of its engineers have degrees in electrical engineering from the university. MCE specified the installation of an ESL Power Systems TripleSwitch™ to provide an easy connection to portable backup power for the life-safety system housed in the AU Haley Center. They installed a 300kW permanent backup generator along with a TripleSwitch that enables users to connect a temporary portable backup generator safely if the permanent generator goes offline.

With CAM-lock-connectors that allow users to connect a portable generator and load bank quickly, the mechanically interlocked TripleSwitch breakers provide a failsafe way to transition from utility power to backup generator or to test a load bank – without endangering users or infrastructure. Now the university’s life-safety system complies with NEC 2017 700.3(F), which requires a means of connecting a temporary alternate power source during maintenance. The new TripleSwitch enables Haley Center technicians to load-bank test the building’s main generator without disconnecting wires inside the permanent generator.

New Hampshire college: Retrofits and new installations

At the New Hampshire college, most buildings have dedicated, permanent backup generators for emergency and standby power. The school tests all generators with load banks annually, as required. Its engineering and utilities team has firsthand experience with generators that have problems due to engine wet stacking. They’ve learned the hard way that a proper, permanent load-banking capability eliminates the dirty job of cleaning out excess soot that collects in a lightly loaded generator’s diesel-exhaust system.

The institution prefers to install permanent manual-transfer switches and its performing arts center already had an outdoor, portable-generator docking station. Engineers opted to add a TripleSwitch because it assures temporary-source-of-power code compliance. Later, while renovating the dining commons, the NEC issue came up again. This time, however, the college requested installation of a TripleSwitch from the outset and now looks forward to capably installing automatically switched, permanent generators at other campus facilities.

Manual-transfer switching made easy at a North Carolina university television transmission site

MEP engineering consultants McKim & Creed work on projects for the state of North Carolina. The firm’s principal engineers have specified the installation of ESL TripleSwitch units in a number of educational settings, including an emergency-power system for a university public-television-station site in Research Triangle Park.

McKim & Creed opted to specify ESL Power Systems products for several reasons, and product simplicity was at the top of the list. Everything is clearly marked, which makes it easy for users to attach cables for a portable generator or load bank. There are no Kirk locks or keys. The engineers also like the fact that ESL is one of the few companies actively developing new products to comply with the NEC 2017 700.3(F) ‘Temporary Source of Power’ code. Finally, ESL makes the engineers’ jobs easier by responding quickly to technical questions about product applications and solutions. For McKim & Creed, that level of responsiveness is a big plus.

Actions

More universities are discovering the advantages of temporary/portable backup power

When it comes to providing on-campus backup power, administrators are faced with a simple question: ‘How fast is necessary?’ Does an application call for immediate, automatic backup power, the kind of critical-facility solution that requires installing a permanent backup generator and ATS, with the unavoidable expenditures, maintenance, and logistics? Or is there a simpler, less-expensive solution: portable, temporary backup power restored within minutes via an ESL StormSwitch™?

For many universities, in a variety of applications, one solution that addresses a number of different challenges is to plan for portable-backup power in the future by installing a manual-transfer switch today.

We’ve installed only ESL units and we can think of no reason to install anything else.

Caleb Cofield is a project manager with Electrical Technicians, Inc., an experienced industrial electrical contractor that serves the Auburn University campus. Caleb says, “We’ve installed at least three ESL manual transfer switches at AU recently. The StormSwitch is one of the most robust – and nice-looking – devices we install. It’s very well made. It’s well organized and it’s got plenty of room for pulling in multiple, parallel lines of conduit and wiring. We’ve installed only ESL units and we can think of no reason to install anything else.”

About us

ESL Power Systems, Inc. is the global leader in providing safety-interlocked power solutions for cord-connected devices. Since its inception in the early 1990s, ESL has become an innovator in designing and manufacturing top-quality electrical products including:

  • Manual transfer switches for emergency power
  • Electrical connecting devices for refrigerated containers and RTGs
  • Ship-to-shore power connection equipment
  • Company switches for set-stage applications
  • Shipyard power distribution equipment
  • Wayside power connection applications

As a certified small business, ESL is proud to offer solutions with the lowest cost of ownership in the industry. ESL demonstrates its continuous commitment to customers by delivering sound workmanship on time and within budget.

Download TripleSwitch Product Specifications

[1] ‘Power Outages On The Rise Across The U.S.,’ Inside Energy. Jordan Wirfs-Brock, 18 Aug. 2014.

Positive Expectations for Reefer Shipping

Erika Thorson

reefer shipping

As projected at the beginning of 2016, this year is proving to be one of the worst for global container shipping, with one exception – reefer shipping.

In written clarifications by The Journal of Commerce, Container News, World Cargo News and Cleanleap, studies show cold chain has proved to be growing strong with frozen food shipments up 4% and chilled products up by 7%. The expectation being that the global refrigerated ocean transportation market will grow steadily from 2016 through 20201.

According to the latest edition of the Reefer Shipping Market Review and Forecast 2016/17, by 2020 seaborne reefer cargo will reach a staggering 120 million tonnes – increasing by an average of 2.5% per annum2. Such increases will have a direct effect on both container lines with reefer capacity and specialized reefer operators.

So where are these predictions coming from? One strong theme in reefer shipping performance is being attributed to the growing demand for food throughout Asia and rapid growth in meat imports into China3. China’s cold chain is now reported to be growing at 25% per year and projected to be worth $75 billion by 20174. In addition to the Asian market, Indian cold chain is also forecast to grow at 25% per year to 2017. This prediction is being accredited to popular fast food supply exports to India tripling over the last six years. Evidence shows the reefer shipping sector is also betting on growth in new and emerging economies, including Cuba. Trade organizations and industry groups have already conducted trade missions to Cuba in anticipation of the lifting of the U.S. trade embargo5.

…having reliable equipment when and where it’s needed is mandatory.

Emerging economies are not the only impact being taken into account, new business segments such as floriculture and pharmaceuticals are anticipated to continue to contribute greatly to the reefer shipping sector. Floriculture, or flower farming, is a $32 billion industry. It ranks as the third-largest U.S. crop, and growers in California make up 75% of the market. Pharmaceutical shippers are also looking more closely at ocean freight for their temperature-controlled shipments. The seasonal nature of floricultural and agricultural products combined with their short shelf lives mean having reliable equipment when and where it’s needed is mandatory. Despite the many current difficulties for the maritime sector, the predicted growth of reefer shipping has an encouraging outlook.

1http://www.joc.com/international-logistics/cool-cargoes/reefer-market-poised-growth-faces-supply-chain-challenges_20160709.html

2http://container-news.com/perishable-reefer-trade-growth-remain-strong-drewry/

3””Reefer Cargo is Hot” World Cargo News Magazine, September 2016, pp. 17

4http://cleanleap.com/brace-yourself-cold-chain-coming/cold-chains-developing-world-catch-and-leapfrog

5http://www.joc.com/port-news/international-ports/cubas-mariel-port-has-ambitious-plan-become-giant-feeder-hub_20160704.html

ESL Featured in Business Energy Magazine

Erika Thorson
ESL Business Energy Switchgear Article
ESL was featured in a recent edition of Business Energy Magazine

ESL was recently featured in Business Energy Magazine. “Switchgear: Matters of Safety and Space” addressed the various concerns of businesses as they work to ensure that their electrical equipment is as safe as possible.

The article highlighted some of the benefits of using ESL’s TripleSwitch as an emergency backup power solution.  Many times, during emergencies, a qualified electrician will not be available, as they struggle to meet the increased need that inevitably follows a crisis. “In place of using lug nuts to pinch raw wire endings, ESL provides cam-style connectors that resemble microphone cords. This lets workers pop connections in and out without cranking lug nuts or fraying wire ends,” which means that anyone can safely operate the unit.

Read more →

ESL Featured in Water Efficiency Magazine: Keeping the Pumps Going When the Lights Go Out

Lesleyanne Daniels
Water Efficiency Magazine ESL Power Systems, Inc.
ESL’s emergency backup power solutions were featured in this month’s issue of Water Efficiency Magazine.

When emergencies or natural disasters occur, preparation can really pay off. Ensuring that water utilities remain operational is a big concern for cities and utility companies. Recently, ESL Power Systems, Inc. was featured in an article written by William Atkinson of Water Efficiency Magazine, focusing on “Keeping the Pumps Running When the Lights Go Out.” There are several strategies to consider to ensure that water utilities will continue to function should your geographic area suffer from power failure. In addition to using efficient pumps, conducting energy audits and proper maintenance, you must also arrange for backup power sources.

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