How to Properly Design and Size A Generator

Introduction

Specifying and sizing a generator for your project can be an overwhelming task . . . but it doesn’t have to be! Collicutt and MTU have a great tool available to assist with this task and simplify it as much as possible.

The tool is called PSSPEC and it is available for download using this link.

What follows is a brief introduction to the PSSPEC tool and how it can be used. This is not meant to be a detailed user manual but it does provide enough detail to get you off to a great start on your generator sizing project.

Should you have questions, want training on the tool, or need further assistance, please reach out to our Collicutt team at the contact information at the bottom of this article.

Getting Started

Once you download, install, and open PSSPEC, you will see the following screen:

 

Select the “Start a New Sizing Project” button. The following screen will appear and this is where the real work begins!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

From this screen you can enter:

  • Customer data and add new customers
  • Project specific Notes
  • The Basic generator information – This is where generator information such as; frequency, voltage, fuel type, rating type, temperature rise, load factor percentage, UL2200 requirements, customer supplied cooling system, and PMG requirements are checked.
  • Specific Site Conditions – this contains the location, elevation, and temperature data
  • Intermittent Loads – This is where you define the loads that your generator will be expected to handle (there is more information on this below).
  • Intake and Exhaust information
  • Advanced options – this allows you to select the % THVD limit

Note that this is an active menu system so an entry in one menu adjusts the menu selections in the other areas.

Once you are completed your entries, click on the “Accept” button and the following screen appears.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Adding Loads

This is where you need to understand the electrical loads that your generator will be powering.

A project’s electrical loading contains a sequence of steps that are defined by the user. Within each step, loads are placed that fit the requirements of the application. All loads within a step are assumed to start at the same time, and steps occur sequentially one after another once the previous step has reached steady state (i.e., generator set has fully recovered to nominal voltage).

PSSPEC offers templates to use for many different types of loads (see graphic below). These templates allow easy selection of the needed variables for the selected load type. The PSSPEC application makes assumptions based on the load type, load criteria, and information entered by the PSSPEC user and populates default values for each load parameter accordingly.

 

 

 

You can select these loads for a particular step by selecting the step and clicking on the “Add Load” button. The screen shown above appears and you select one of the options which will bring you to a screen that allows you to adjust specific parameters for the selected load.

One you are finished adding load steps and loads, you can select the “Sizing and Rating” button on the left side of the screen. This starts the generator sizing and selection process.

 

Sizing and Rating

When you click the “Sizing and Rating” button, PSSPEC runs its calculations and selects the recommended best fit generator using all of the data that you have provided. This is illustrated in the graphic below.

 

 

Note that this window will also display oversized and undersized generator sets that may meet project requirements.

Any generator set in the list can be selected and a sizing report can be generated to provide a ‘mini spec sheet’ for the user. Multiple sizing reports can be created for different generator set models. Just select the generator sets you are interested in and click the Report button that shows up on the left of the screen (see the graphic below).

 

 

These reports can be used as a convenient quality check to ensure the generator selected meets your design requirements and then included as part of your generator specification package. If you find errors or things that you missed you can go back through the process described above and make the changes and additions and recreate the report to include your changes.

In Conclusion

This was a very condensed tutorial which illustrated only a small fraction of PSSPEC’s capabilities. The best way to understand it’s capabilities is to dive in and start sizing some of your projects!

If you would like us to provide some training for your organization or just need to have some questions answered, be sure to call us or email us at the link below.

888-682-6888    info@collicutt.com

 

Note: Sizing of the generator is the responsibility of the “engineer of record.” Input data and the output from PSSPEC must be reviewed and approved by the responsible engineering firm.

 

Finally, see these article for related content:

 

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Do You Need a Generator Specification? Let Our Software Do the Work For You!

Many of Collicutt’s long time customers are engineering firms. One of the things these engineering firms need for each project is a prepared set of bid packages for each major scope of work on that project. These bid packages will be sent out to potential suppliers of that scope of work so that the supplier can propose a solution complete with an accurate price.

The Challenge

This means that the bid package must have sufficient detail to get price certainty. Without this detail, prices between suppliers will be difficult to compare and the engineering firm will have no way of knowing if they are selecting the best solution.

To solve this problem, the bid package must contain a specification that defines the exact performance details for the piece of equipment or structure under development.

One of the most important specifications that these engineering firms need to complete is an emergency generator specification. This specification defines the generator that will provide emergency power should the power grid fail. Among many things, this specification needs to contain requirements for the following:

  • Submittal process
  • Quality assurance process
  • Warranty
  • Approved manufacturers and approved manufacturing locations
  • Industry standards compliance (UL, CSA, ANSI, NFPA, EPA, etc.)
  • Performance requirements
  • Engine requirements
  • Alternator requirements
  • Electric load definition
  • Switchgear requirements
  • Fuel type(s) and fuel system requirements
  • Environment constraints (emissions, altitude, temperature, size, noise, etc.)
  • Control and monitoring
  • Overcurrent and fault protection
  • Voltage regulation
  • Enclosure requirements
  • Installation, interconnections (fuel, cooling-system, exhaust-system, grounding and electrical connections)
  • Commissioning, testing, and start up
  • End user training
  • Life cycle maintenance

Although it sounds simple enough, the creation of specification like this can be a complicated and daunting task!

The Solution

So, what do you do if you are in this situation and don’t have a detailed specification for an emergency power generator set but need one for your project?

You can leverage our unique sizing software to estimate the generator capacity required for your project as well as create your own set of specifications. Just answer a detailed list of questions and the software will prepare an MS Word style document that you can further edit to fit your bid specification package.

Call us or email us at the link below for assistance or download our software using this link and build your own custom specification!

888-682-6888    info@collicutt.com

You can also download the 260kW NG genset spec that is attached to this post to get an idea of what a generator spec looks like.

Finally, see this article for related content – Don’t Make This Mistake When Buying Your Generator!

 

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Customized Rental Solution!

One of our customers in Beverly Hills was doing a major office renovation and they required temporary electric power for the duration of the work. This seemed like a simple enough request for our rental group to handle but there were some challenges that had to be addressed!

The Challenge

The challenges were generally centered around the constraints of the job site and included:

  1. The temporary generator could not be parked on the street due to city bylaws
  2. The only other available locations for a temporary generator came with their own challenges:
    • A very small underground parking stall with extremely tight access and inadequate ventilation to allow an engine to run for an extended period of time
    • The top of a parking structure which would require a crane to lift it into place
  3. Noise restrictions were in place due to the proximity to other businesses
  4. California  has some of the strictest emissions requirements and building code requirements in North America. This means that power generation equipment must be able to meet the strictest emission standards and must be designed to handle earthquakes which are also common to California

 

The Solution

Our rental team worked with the customer to determine the potential power demand that they would experience during their office renovation. Once our team understood this requirement, we began to look at our rental fleet and selected a few potential options. From these options we narrowed down the selection to a rental unit that was the correct size, met the noise restrictions, and met the emissions requirements.

We then worked with our customer to provide a temporary venting solution for the generator exhaust. This had to meet the local building code requirements as well as the exhaust venting specifications for the generator. Once this was done, our rental team coordinated the generator drop off and set-up (props to our delivery team for backing this unit into place!) ensuring that our customer had the electric power they needed for the duration of their office building renovation project!

 

For more information on a rental solution or any other power generation solution, contact us via email or at the number below:

1-888-682-6888 or info@collicutt.com

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2250

Data Center Expansion

One of our data center customers in southern California had recently been experiencing an increase in demand so they began expanding their center’s capacity. As the number of data servers increased, their requirement for emergency back up power was also increasing. Unreliable power is the biggest threat a data center can face! Power quality issues can cause equipment failure, downtime, data corruption or data loss, none of which are acceptable outcomes. So, this requirement to upgrade their emergency generators was critical!

Because Collicutt has been providing service work for them and their existing 2250kW generators for a number of years, we sat down with them to understand the challenge that they were facing.

The Design Challenge

Our customer had a few design constraints that needed to be solved. They obviously had a emergency power shortage but they also had the following issues that had to be addressed:

  • Size restrictions with their facility limited the footprint of the generators that they could use
  • California  has some of the strictest emissions requirements and building code requirements in North America. This means that power generation equipment must be able to meet the strictest emission standards and must be designed to handle earthquakes which are also common to California
  • Noise restrictions due to the proximity to other businesses
  • An existing generator that was no longer up to code and could not be made compliant
  • Switchgear upgrade project running concurrently with the generator upgrades
  • Programming to ensure paralleling of the units worked seamlessly with all the upgrades underway

The Solution

For the first unit they required, we designed and provided a custom 2250kw standby generator with a level 2 sound attenuated enclosure and a 3540 gallon subbase fuel tank. The fuel tank is UL142 double walled with secondary containment and rested just beneath the generator base. The enclosure had fixed intake louvers and a vertical discharge plenum to help hamper excessive noise to protect surrounding businesses. The enclosure was custom made with aluminum side and roof panels to ensure a non-corrosive housing designed for prolonged life. We also provided a critical grade silencer to quiet the large generators exhaust to meet city noise restrictions.

When the trucks showed up on site with the first generator and all its components, the customer’s crane company was a “no-show” due to equipment failure. As the old saying goes, “time is money” and a data center construction site is no exception. Collicutt was able to call on one of our crane contractors and get them out to site on short notice. They were able to successfully offload all of the equipment and maintain the schedule!

Our customer has now placed an order for a second 2250kW with the same basic specifications. Collicutt will be removing their non-compliant generator to make room for this second 2250kW. We will also assist them in selling the non-compliant unit using our  surplus equipment website and sales team.

In addition to this, we we able to provide paralleling programming and implementation so that when the new generators are installed and the switchgear upgrades are completed, they will be able to parallel these two new units with their existing generators.

This solution will provide them with high quality emergency power for years to come helping to guarantee their customers have secure data and data processing regardless of inevitable utility power outages.

 

 

 

For more information on this or any other power generation solution, contact us via email or at the number below:

1-888-682-6888 or info@collicutt.com

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Emergency Power for a High Rise

A few years ago a customer approached us with a project that they were about to take on in Southern California. They were looking at building a 600 unit, residential high rise apartment complex complete with some major retail stores in the ground floor. They were required to provide an emergency power generation system for this building and this is where Collicutt got involved.

The Design Challenge

There are always challenges to sort through with any project and this one was no exception. Besides the usual design constraints associated with projects in California like strict emissions compliance and seismic ratings, this project had some unique aspects that had to be addressed.

  • First, the generator would have to be installed in the parking garage of the building prior to the construction of the upper floors of the building. This put us on the critical path for project construction. We had to deliver on time!
  • Second, because the overall building design was still in process, we needed to allow for late changes prior to placing the generator into production in the event that we would need to upsize or downsize the generator and its components
  • Third, because of the seismic requirements and the fact that the generator was to be installed inside the building, the fuel tank had to be equipped with ballistic rated retainer walls. Basically, this is a double walled fuel tank that is filled with cement between the inner and outer wall to provide a puncture proof solution for fire rated indoor applications
  • Fourth, because the unit was located indoors, it needed to be equipped with a special exhaust silencer to meet the city sound requirements for indoor applications.
  • Finally, the installation of the generator would need detailed planning, coordination, and safety oversight. Due to the construction site location, offloading and placing the generator would require local road closures with the added challenge of dealing with overhead power lines. This meant that we would have to coordinate a crane and the trucking company within a very tight timeline while ensuring we had the time for a safe lift!

The Solution

Our Collicutt team worked closely with our customer throughout the design phase of this project. As the design progressed the customer realized that their electrical load had increased. Because of this, we upsized the original 1000kW generator to a 1250kW unit designed to provide enough critical power to meet full load requirements with a reserve factor of 10%. The model we selected was a 16V2000 DS1250 with IBC rating, complete with a roof mounted DPF and a UL2085 rated fuel tank.

In addition to this, there were various automatic transfer switch changes and breaker adjustments that the customer requested and we were able to accommodate within the time constraints. We were also able to coordinate the appropriate air quality permit for the customer so that their generator has all the permits required for operation.

The end result was that our customer received the generator at site on schedule. Our trucking and crane contractors were able to safely unload the generator, lower it two stories into the parking garage, and remove their equipment within the allotted road closure permit constraints.

It was a great team effort and now the building program can go on!

 

For more information on this or any other power generation solution, contact us via email or at the number below:

1-888-682-6888 or info@collicutt.com

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Emergency Power Solution for a Television Network Expansion!

A television network in Southern California was recently renovating and expanding their facility. As part of this expansion, they required an emergency power generation system.

As most people know, California has a very unstable power grid so most businesses need to have their own back up power system. This requirement is even more important for a television network as they simply cannot lose power during a power grid outage . . . this is when their viewers need them the most!

Complications

To complicate things, California has some of the strictest emissions and building code requirements in North America.

California emissions are controlled and regulated by 35 separate air quality management districts. Many of these districts have unique emission control requirements so it is critical to understand them and apply the correct solution. The wrong application can result in costly fines and mitigation requirements. In addition to this, the generator for this application needed to be IBC rated . . . basically constructed in a way to ensure that it can withstand and operate after a seismic event.

Design Process

Understanding these constraints, when the TV network started their design process, they reached out to Collicutt. Our professional sales and design teams worked with them and their engineering contractors to define the building electrical loads, design constraints, and their construction schedule.

The Solution

The outcome from this process was the generator shown in the photo above: a 1250kW, fully enclosed, IBC rated, MTU 16V2000 DS1250 solution complete with a Rypos filter to handle the strict emissions requirements. We were able to deliver this unit within the designated construction schedule.

When we heard that their construction schedule was delayed due to COVID, we were able to store the generator at our secured location for a number of months. During this time we provided them a temporary rental generator to make sure they had backup power until their facility was completed.

When we got the call that they were ready for their generator, we arranged for the crane and transport shown in the photo above. We delivered the unit and came back to site for commissioning and start up. Once the start up was complete, we provided training for the customer, removed the rental genset, and “gave them the keys” to their new power generation system!

For more information on this or any other power generation solution, contact us via email or at the number below:

1-888-682-6888 or info@collicutt.com

 

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New Tier 4 Final 450kW Mobile Generator

Collicutt is pleased to announce our new line of Scania powered, tier 4 final, 450kW trailer mounted generators! We are ready to start taking orders for this exciting new product line!

Some of the product features are listed below. Refer to the attached product data sheet for all of the details.

  • Scania DC16-084A
  • Tier 4F
  • 450kW prime rating
  • 120 liter DEF capacity
  • 620 gallon UN31 fuel tank
  • Paralleling capability
  • Stamford HCI534D alternator
  • Switch between 208V and 480V
  • 400 amp camlocks

Call us or email us for details!

Collicutt Energy Services – Powering tomorrow through unrivaled solutions today!

1-888-682-6888 or info@collicutt.com

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Monitor Your Power Generation Equipment in the “Cloud”!

One of the big takeaways from the unprecedented events of this last year is the requirement to work remotely, often with limited access to our facilities. This can pose major challenges when our power generation equipment is onsite and our operations and maintenance teams are working from home!

It has become more important than ever to have a cost effective solution that provides peace of mind that our power generation needs can be met without being onsite.

To meet this need, Collicutt is pleased to announce the release of our secure, internet based, Remote Monitoring Solution. With this solution you can monitor your power generation equipment from anywhere in the world through a secure internet connection. The solution provides up to date status conditions for critical points as well as alarm indications for conditions that may compromise your units ability to provide power during a power outage.

We offer three levels of service as shown in the graphic below and would be happy to discuss this solution with you in detail!

Call or email us for details on how we can get you set up!

Collicutt Energy Services – Powering tomorrow through unrivaled solutions today!

1-888-682-6888 or info@collicutt.com

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How to Implement a Fuel Blending System

Air quality management districts, AQMDs, are continually updating their standards for reciprocating engines and the resulting emissions. Although the changes are made with the best intentions (e.g., reducing airborne pollutants), these changing standards often impose large technical challenges and require equipment upgrades or replacements which adds unexpected costs for business and industries.

Wastewater Dilemma

This is the situation one of our wastewater treatment customers found themselves in when a change in their local AQMD regulations instigated a large change in what was allowed for natural gas combustion.

This wastewater facility had three large CHP systems that used off-gas from the wastewater (produced through a digester process) as the main fuel source and natural gas as a backup fuel source. The CHP system provides electrical power for the plant, electrical power for the utility grid, and heat for the digester. The system had a combined electrical/mechanical efficiency of around 90% while removing GHG emissions from the environment so it was critical that it continue to run!

The challenge that the new AQMD ruling created was that the allowable natural gas consumption in their engines was changing from 100% to only 49%. However, the engines were originally designed with a dual fuel system that could run on either 100% natural gas or 100% digester gas but not a blend of the two fuels.

This change in allowable fuel ratios caused a big issue with the plant operations! (more…)

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