Match every drive the mechanical schedules and one-line call for to the section’s equipment schedule and motor data, then confirm whether the section keeps the HVAC or the industrial application, how speed is commanded and reported to controls, whether bypass is required, and where harmonic limits are measured. Then check each drive’s enclosure, disconnect, location, ventilation, and grounding on the plans.
Assemble the review package
Gather the mechanical equipment schedules for fans and pumps, the electrical one-line, motor and panel schedules, the plans showing where each drive is mounted, the controls points list and sequences of operation, any harmonic study or filter details, and the issued Section 26 29 23 with Section 26 20 00. Review one drive from its feeder to its motor and controls points before assuming the rest of the schedule matches.
WBDG publishes UFGS 26 29 23: Adjustable Speed Drive (ASD) Systems Under 600 Volts as a public guide-specification reference (accessed October 18, 2026). Use your project’s issued specification and amendments for the actual comparison; the guide specification does not automatically govern your project. The checklist below is an original suggested review workflow, not a reproduction of the UFGS requirements.
Eight checks to run against the issued set
Use one record per location or system. The CSV contains the same eight prompts plus fields for source revisions, observed evidence, the review owner, the decision, and closure references.
| Check | Sources to compare | Question to resolve |
|---|---|---|
| Drive list and motor match | Equipment Schedule article + mechanical schedules + motor schedule | Does every motor the mechanical schedules mark as variable speed have a drive on the electrical drawings, with matching identifiers and motor data? |
| Application selected | ASD for HVAC Application and ASD for Industrial Application articles + schedules | Does the issued section keep the application that matches the equipment drawn, and are the operator controls it describes compatible with how the drive will be used? |
| Controls interface | ASD for HVAC Application article + controls points list + sequences of operation | Is speed commanded by the signal or network the section selects, and do the controls drawings pick up the run and fault relays it requires? |
| Bypass | Adjustable Speed Drives (ASD) article + one-line + sequences of operation | Where the section keeps bypass and isolation contactors, do the drawings and the sequence show what the motor does in bypass and how it is selected? |
| Harmonics and line reactors | Adjustable Speed Drives (ASD) article + one-line + any harmonic study | Is the point where harmonic limits apply shown, and are any line reactors or filter assemblies drawn with space and a feeder? |
| Enclosure and disconnect | Enclosures article + plans + equipment location | Does each drive’s mounting location (indoor, outdoor, or on equipment) match the enclosure the section requires, including a heater outdoors and the door-interlocked disconnect? |
| Location, ventilation, and clearances | Installation Drawings article + electrical and mechanical plans | Do the plans show each drive and motor with working clearance, cable routing, and room ventilation for the heat the drives give off? |
| Grounding and surge protection | Grounding and Sensor and Control Wiring Surge Protection articles + grounding details | Are the drives grounded to the main distribution as the section requires, and is outdoor control or sensor wiring identified for surge protection? |
Worked example: an air handler fan with no drive on the electrical set
Illustrative example: the mechanical air handler schedule lists a supply fan as variable speed with a drive by the electrical contractor. The electrical motor schedule shows a combination starter for the same fan, and the controls sequence modulates fan speed from duct static pressure.
Ask the mechanical and electrical engineers to confirm the fan gets a drive, then add it to the electrical schedule and plans, coordinate the controls points for speed command, run status, and fault, and confirm whether bypass is required. Recheck other variable speed fans and pumps for the same mismatch before closing the item.
Avoid a false conflict
A drive shown on the mechanical schedule is not proof it is fed, located, and wired. The drive, the motor, and the control points often live on three different sheets drawn by three different people.
When requirements disagree, follow the project’s document-control and clarification process. Do not assume that drawings always override specifications, or the reverse. Identify the exact sources and request an authorized decision.
Close the issue across the affected documents
Record the location or tag, drawing and specification references, issue dates, observed difference, and the decision needed. Assign an owner and keep the item open until the response identifies the governing requirement. Check the revised drawings and specification references together; a response email alone may leave the issued package inconsistent.
For the overall process, use the guide to drawing and specification conflicts. Mark an inapplicable checklist row with a reason, and distinguish a verified correction from a question that still needs design information.
Where Groundbook fits
Groundbook’s drawing and specification review helps investigate potential disagreements in the documents you supply. Include the relevant specification sections and drawing references, then verify the cited evidence with the responsible reviewers before acting on a finding.