Continuing with my series on basics, we need to look at one of the biggest problems today with equipment replacement and new installations. Too often today, the equipment never gets a proper start-up. The installer on the job has one “purpose” and that is to set the unit, connect the duct work, gas pipe, maybe the control and power wiring (or the electrician does this) , install any field installed accessories and go on to the next job. The feeling is that the manufacturer SHOULD have tested the unit and made sure everything works.
Yes, the manufacturer does perform a run test on the units and knows that when the unit left the factory, all components functioned. What they do not know is the job specifications for the new unit or existing conditions for a replacement unit. This is true for both commercial and residential equipment but it is even more critical for the commercial unit to be properly started.
Let’s list some things that need to be checked as part of a proper start-up!
The manufacturer does not know what the engineer designed the external static pressure (ESP) for the duct work so the blower is probably not set to proper CFM for the job. Is there a curb adapter adding to the external static on replacements? Is there a freq drive on the unit? Is it properly set up? What field installed accessories (economizer, etc) were added to the job? So air flow needs to be set on the job to meet the CFM requirements of the location and installation.
What is the building gas pressure? Will an external regulator be needed? How many stages of heat? What is the manifold pressure? This will need to be set to assure proper heating of the space.
What is the power voltage? Was the tap on the transformer properly set? Is there a wild or stinger leg? Is it a scroll compressor that has to be checked for proper rotation (phasing)? Power to the unit needs to be checked.
Today, what is the control system — BAS, simple thermostat, VVT, and so on? Does the unit need to have parameters programmed into it to meet the job specifications? Does the contractor have the proper software and “tool” to do this? Is it a communicating control that can be accessed on the internet? Any of these need to be checked and set.
Unfortunately, too many companies today think all equipment is “plug and play” or “Set and run”. While this may be true of field installed accessories, it DEFINITELY is not true of the base equipment itself — whether residential of commercial. All of the items above (and probably a few more depending on either field or factory installed accessories) are part of a proper start-up.
In my next few posts, I will be addressing the various items that need to be checked and set as part of a proper start-up. REMEMBER – a proper start up of equipment reduces warranty and call-backs and gives your customer the properly operating equipment that they “contracted” with you to give them.