ASHRAE Journal - February 2014 - 56

TECHNICAL FEATURE

TABLE 3 Sample checklist of the primary control-sequence issues the CxA should

TABLE 4 Sample checklist of the plumbing concerns the CxA should review during DPC.

Control schematics and sequences must be clearly written and specific to
the system, equipment, application, and operations. Control sequences should
1
be written in step-by-step form, using simple, clear, and concise language.
Sequences must cover all foreseeable scenarios, including life-safety events.

1 sitated by the specified water fixture units (WFUs) and drainage fixture units

check during DPC.

Plumbing pipes and equipment sizes must match the requirements neces(DFUs).

Water pressure (and any pressure boosters) must be sufficient for the system
configuration, building height, and fixture types.

2 and shut-down, as well as how to handle equipment failure during power loss

Verify the need for (and specification of) expansion tanks and/or recirculating
pumps.

Pressurization sequences and equipment components must be appropriate for
the application.

Verify that hot-water circulating pumps will have balance valves and pressuregauge test ports.

Verify that plumbing systems will be able to handle high-occupancy loads
during special events.

Sequences must specify proper control procedures for equipment start-up
or malfunction.

4 Temperature and pressure reset sequences must be described in detail.

* Inadequately defined building pressurization sequences; and
* Failure to specify temperature and pressure reset sequences.
Table 3 is a sample checklist of the primary control
sequence issues the CxA should check during DPC.

TABLE 5 Sample checklist of electrical-system factors the CxA should review

during DPC.

Verify electrical/mechanical design coordination, including equipment location,
voltage, and load and control specifications.
Verify all standby/emergency power requirements, including the redundancy

2 approach. Ensure that proper need and control strategies are in place for

backing up different levels of standby power.

Plumbing Design Review
Plumbing is usually not as prone to problems as
other mechanical areas (perhaps due to the many code
requirements plumbing systems must satisfy). But
plumbing-related issues can prove problematic and
should be validated by the CxA, including:
* Improperly sized fixture inlets;
* Inadequate water pressure from supply source;
* Lack of expansion tanks on closed systems; and
* Failure to consider peak loads during special events.
Table 4 is a sample checklist of the plumbing concerns
the CxA should review during DPC.

Ensure that proper lighting-control designs and associated control strategies
are in place.

Verify correct fire-alarm sequences and interlocks are defined for specific lifesafety operations, such as standard alarming, shut-downs, smoke exhaust, etc.

Ensure that motor controls, starters, and variable frequency drives (VFDs) are
coordinated with the appropriate mechanical systems.

Verify that the specifications call for full-power electrical-system quality
testing, including:
* Current load balance on each leg.
6
* Current to ground measurements.
* Voltage balance on each leg.
* Current and voltage total harmonic distortion (THD).

Commissioning-related electrical issues can have
a major impact on whether a building can satisfy
owner expectations. We've seen many problems that
seem to surface repeatedly, including:
* Failure to coordinate electrical panels with mechanical and/or architectural components;
* Improperly sized emergency generators;
* Incorrectly performed generator testing procedures;
* Improperly performed electrical power quality testing and connector adequacy testing; and
* Different electrical specifications for mechanical
equipment and electrical service voltages.
Table 5 is a sample checklist of electrical system factors
the CxA should review during DPC.
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FEBRUARY 2014

Ensure that project documents call for load tests of uninterruptible power
system (UPS) equipment and battery discharge rates.

Verify that the documents call for an 8- to 12-hour standby/emergency
generator performance test using an appropriate load bank.

Electrical System Design Review

Ensure that connected-lighting load-density specifications do not exceed code
or LEED limits.
Verify that the documents specify permanent service-usage labels for all

10 electrical equipment and that all panel-board schedules are to be filled out at

project completion.

Ensure that the specifications call for all power connections over 5 horsepower

11 be photographed with a thermal-imaging camera while operating under full

load to identify "hot spots" and improper connections.

Project Design Manual
During DPC, the CxA should collaborate with the
owner and the design team to decide which documents
will be included in the project design manual (PDM) (or
"systems manual" within the LEED community). While
every project will have its own unique design manual,
certain documents should be included in every PDM.
In addition to the final OPR, BOD, and commissioning
plan, the PDM should include:

ASHRAE Journal - February 2014

Table of Contents for the Digital Edition of ASHRAE Journal - February 2014