Even when not mandated by code, periodic testing of emergency generators to ensure they are in good working order should disaster strike is a key component of good building operations strategy. How frequently to test is generally predicated upon several variables, including building occupancy, use of the building, and cost of interruption of business.
There are two options available to decision makers on how to test emergency power equipment. One way is to conduct building load testing, which puts the full building load on the emergency generators during an “off” period of time. The other way, which offers a lot of tangential benefits, is load bank testing with rented load banks or load banks the facility itself owns, which means the generators can be tested without shutting down a whole building to switch the power source to emergency generators.
Whatever route a facility takes – load bank testing with its own load banks or load bank testing with rented load banks – it is I important to keep accurate records of when and how the emergency generators were tested. This record keeping can be done by the company or by a third-party company if one is hired to do the testing. Here is a link to a good read: Load Bank Testing, White Paper
The ability to load bank your gen sets or SEP in my opinion, is a must have rather than a need or like to have. Specifically, installed loadbanks, designed and wired into your paralleling equipment from day one.
ReplyDeleteIf you do not have a load bank installed, the option for leasing is available, although, in my opinion, the use of the leased equipment has risks involved. Quality of the equipment can vary depending on the care that is taken by the owners of the equipment, the precise methods of connecting to your POC and the associated hazards with opening up gear to attach the load bank cables.
I can speak for both, where a built in system has the methods of procedures in front of the OE's at all times. The frequency and use of the equipment is based on the classification of your SEP when installing, to be correctly identified as back up power , rather than load shedding or shaving. The NOx emmisions vary in each state and if not identified correctly will limit you to specific number of testing hours for your SEP.
Proper care of the built in load bank is essential and can be easily be tested and cared for over a long period of time by qualified inhouse OE's or manufacturer reps.
There are many advantages and flexibility to owning your built in load bank and associated control center, typically located near the SEP control center or paralleling equipment used for starting and syncing your SEP to the buss or starting and stopping with specific guidelines for testing and gives you the owner operator more control of and quality assurance based on the recommended frequencies of testing, to include: Semi-Monthly starting and stopping of your SEP, as a whole or for individual SEP testing. Monthly synchronizing to the the SEP buss, transferring of non critical loads such as off line chillers, with separate transfer switches designed to be manually operated. This option gives you the flexibility not only see how your SEP reacts to A-Typical 100% resistive load provided by the load bank with a PF of 1.0 or you can transfer said equipment such as chillers and or off line pumps and chillers to SEP power. This option has more advantages as you can see how your real equipment load reacts when on SEP, or back up power with a much needed PF of .85. The option to have inductive load available during SEP testing is a must have. Regardless if you have the maintenance performed internally or by the OEM, the inductive loads will typically show you more potential issues or warnings prior to equipment failure, i.e. The ability to see and control loads with realtime or intended use load and the statistics and behavior of your SEP can be documented and give your teams more confidence with the SEP as a whole.
The load banks typically do not have inductive power controls as most are a series of heaters, or giant blow driers. Essential for loading up at least 1/3 of your SEP capacity, blowing out and loading up your SEP as a whole system, where your paralleling control panel or totalizing board can be monotered for phase imbalance between your SEP, meaning, if any of your VR's on your generators are in need of voltage/frequency adjustments, that can be easily performed on site by the OE's or OEM's.
There are so many advantages to load banking your SEP, to many to list on this blog at one time, the bottom line is, if you want your capital expenditures to last and to be reliable when you need them, having a load bank is a essential part of any SEP operation and will save your company money by catching these potential issues up front, rather than finding out the hard way when the power goes out!
The payback or ROI on a load bank, can be instantaneous.