21 - AC/R General Maintenance *

Question 1

Recite the procedure for performing a full PM on a piece of AC/R equipment

Answer 1

Change filters
Check and adjust belts, check alignment for belts and sheaves
Check operating controls
Check refrigerant pressure
Check temp split
Check voltage and amperage
Check condenser fan blades
Lubricate motors, bearings
Visually check for leaks
Check operation of dampers
Clean coils, drain pans, and drain lines
Check or calibrate thermostat

Question 2

Why is preventative maintenance important for AC/R equipment?

Answer 2

Preventative maintenance is important for HVAC systems because it can help keep the system running properly, which can lead to many benefits including improved efficiency, better air quality, reduced repairs, and longer system life.

Question 3

How to change filters

Answer 3

1. Ensure proper quantity and size of replacement filters before beginning replacement.
2. Shut off equipment
3. Remove old, dirty filters
4. Replace with new, clean filters
5. Date new filters
6. Turn equipment back on

Question 4

How to check belts/sheaves, check alignment, adjust, and replace belts.

Answer 4

Checking belts:
1.

Checking sheaves:
1. Inspect pulleys for wear using a pulley groove gauge. Check for wear, burrs, nicks, gouges, and severe scratches. Write up for replacement if necessary.

Checking alignment:
1. Using either a straight edge or piece of string, check if 4 points of contact can be achieved between the motor and fan pulleys. Misalignment should be less than .1” per 10” of span.

Adjusting motor position/belt tension:
1.

Replacing belts:
1. Remove old belt
2. Check pulleys for rust, oil, grease, dust, dirt and other foreign materials. Clean if any are present.
3. Install new belt onto pulleys
4. Check belt tension using belt tension checker with belt tension chart. Proper tensions should be the lowest possible tension that will prevent the belt from sli