MSC was recently on a project in which the master schedule only allotted two days for startup of HVAC and process equipment. Having no “float” on schedules in the event of problems at startup is a very common occurrence in our industry that assumes that everything will start and run flawlessly when the time comes. This can be a frustrating situation, but it’s just the way schedules are built; once an end date is set, it’s set, no matter what the issues may be.
This does not mean, however, that there aren’t things that can be done to support the schedule beforehand and minimize problems in the end. MSC recommends “preflighting” as much of the equipment and systems as possible to help identify and remedy problems before they can occur at startup.
This means checking that all power wire and control power from UPS are correctly installed and terminated properly. It also means bumping and checking rotation of pumps and fans through variable frequency drives to make sure they operate properly both locally and remotely. This can sometimes apply to fans and motors that are not on VFDs, as well.
Next, make sure compressed air is available, has a pressure reducing valve, or PRV, if needed, and is set at the right downstream pressure to the equipment. Verifying proper airflow and/or water flow to and from the equipment within 10% is another must. Lastly, make sure all control wiring is run and terminated properly and all remote instruments and control devices have been loop checked and are ready to go. Following this preflight checklist will often expose problems such as missing utilities like UPS power or compressed air, or missing add-on options that should have been ordered with the equipment.
Remember, a little bit of pre-commissioning can go a long way in nipping HVAC and process equipment problems in the bud and keeping a project on schedule.
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