Belts, pulleys, fan motors, and guards need service clearance. If duct blocks routine fan maintenance, it will come back during startup, commissioning, or warranty.
Do not install duct or hangers where they block required service access.
Check
Identify which side of the fan or unit contains the motor, belts, pulley, drive guard, or service panel. Use the submittal or visible cabinet layout.
Check the required service clearance in the submittal or manufacturer drawing. Do not assume a person can work there just because the panel can crack open.
Measure the clear distance between your duct/hanger and the service side. Compare it to the required clearance.
If duct enters that service zone, check whether the run can raise, shift, shorten, or change transition shape before hangers are finalized.
Do not finalize supports on duct that blocks routine belt, pulley, motor, or fan access.
Steps
Identify which side of the fan or unit contains the motor, belts, pulley, drive guard, or service panel. Use the submittal or visible cabinet layout.
Check the required service clearance in the submittal or manufacturer drawing. Do not assume a person can work there just because the panel can crack open.
Measure the clear distance between your duct/hanger and the service side. Compare it to the required clearance.
If duct enters that service zone, check whether the run can raise, shift, shorten, or change transition shape before hangers are finalized.
Do not finalize supports on duct that blocks routine belt, pulley, motor, or fan access.
Say this to your foreman
My duct is within [measurement] of the motor/belt/fan-service side of [unit tag]. The submittal shows [required clearance]. I think I have a maintenance-access conflict. Do you want me to adjust the run before we finalize?