HVAC, Back Up Power and Lessons Learned

Many HVAC systems are designed to run during a power failure in a brown out or black out. They are most commonly cooling loads like data rooms, IDF and MDF rooms. Larger loads such as air handlers, pumps, DX cooling, fan powered boxes and condensate pumps will run on generator power. At a loss of utility power an automatic transfer switch senses the loss and starts a generator and 6 to 10 seconds later it then transfers to emergency power to run the critical loads.

Sensitive electronics such as PLCs, CPUs and BAS I/O are recommended to be on UPS power or interrupted power supply. The UPS whether central or localized provides constant power when utility power is lost and before the generator power is established. The UPS battery backup also provides clean power preventing voltage spikes and dips which can severely affect sensitive electronics.

On a recent project it was discovered that a customers BAS system only had UPS power to certain panels and not others. The loss of power created problems with restarting critical loads. Small condensate pumps were not connected to any emergency power or UPS power and created water leaks. VAV and fancoil units failed to run which raised temperatures in critical areas.

Witnessing what had occurred and documenting the emergency sequence in detail allowed MSC to recommend local UPS power to specific loads and also add other equipment such as circulation pumps to the emergency generators circuits. After several minor changes and adds the critical systems were retested successfully.

MSC recommends a bi-annual preventative maintenance program and testing criteria to ensure critical HVAC systems run properly when they are most needed.

About MSC - The Go To Guys

We are a service sub-specialist in the technical intricacies of HVAC, process cooling, and building automation systems in commercial, industrial, and institutional environments. MSC is recognized as the leading industry expert in solving elusive problems and attaining peak performance from clients & mechanical equipment and overall systems.

Located in northern New Jersey, MSC is the only specialized contractor of our kind in the Northeast and Mid-Atlantic regions. We are MSCA STAR-qualified, NEBB-certified, fully-licensed in electrical, plumbing and HVAC, and our engineers and technicians are the most knowledgeable in our field.

Mechanical Service Corp.
41 South Jefferson Road
Whippany, NJ 07981
732-884-5000
http://www.mscnj.com