No Tier is not spelt wrong for this instance. In this article we are going to discuss an overview of the U.S. Government's regulations and guidelines when it comes to air pollution with the overall improvements that have taken place over time. EPA (Environmental Protection Agency) sets regulations which manufactures must follow as overtime regulations become more strict. As developing new technologies to meet EPA's new regulations over time manufacturers have created less negative impact to businesses.
EPA Tier Breakdown:
1) Tier I: 1994 - 1997 Intent of focus on diesel power vehicle engines
2) Tier II: 2000 - 2005 Focusing on sulfur allowed in diesel fuels. Sulfur can be a cause of contamination to catalytic converters and particulate filters.
3) Tier III: 2006 - 2008 Is a time when exhaust emissions became restricted for 50 - 750hp engines forcing compliance beginning of 2007.
4) Tier IV: This being the most strict regulation, requires 90% reduction of DPM. With advancements in technology allowing for more control opportunities and was created in 2008 - 2015. Diesel Particulate Matter are particles by a diesel exhaust.
In Power System Service's Tools & Resources page, please refer to Tier Rating for EMERGENCY Power or Tier Ratings for NON-EMERGENCY Generator Sets charts for a spreadsheet breakdown. Definition of "Emergency Standby" are generator installations that have limited operation upon the loss of normal power from main utility power grid. Tier IV regulations must be fitted with a permanent label stating that they are for emergency use.
The final authority on emissions regulations governing emergency standby diesel generator sets rests with Environmental Protection Agency (EPA) for access to their site go to: www.epa.gov