12/18/2015

Water Chillers and Maintenance part 3 Chiller data logging form


Water Chillers and Maintenance
 part 3
Chiller data logging form

annual preventative maintenance




Monthly, quarterly, and annual preventative maintenance:

1. Clean evaporator every 2–4 years (annually for chillers serving air
washers or other “open” cooling loads).
2. Quarterly, calibrate pressure, temperature, and flow controls.

FIGURE 7.1 Chiller data logging form.
3. Annually, inspect starter wiring connections, contacts, and action.
Tighten and adjust as required. Perform thermographic survey every 5
years.
4. Annually, test the operation of safety interlocks devices, such as flow
switches, pump starter auxiliary contracts, phase-loss protection, and so
on. Repair or replace as required.
5. Annually, perform dielectric motor testing to identify failures in motor
winding insulation. For large chillers (100 tons or larger), additional

annual motor tests are required to test for imbalance of electrical
resistance
among windings, imbalance of total inductance with phase
inductances, power factor, capacitance imbalance, and running amperage
versus nameplate amperage.
6. Annually, check the tightness of the hot gas valve (as applicable). If the
valve does not provide tight shutoff, replace it.
7. Annually, change the lubricant (oil) filter and the drier.
8. Laboratory analysis of the lubricant should be performed annually
during the first 10 years of chiller life and every 6 months thereafter.
[This oil analysis will define the moisture content (not to exceed
50 ppm), oil acidity (maximum 1 ppm) that may indicate oil oxidation
and/or refrigerant degradation due to high temperatures, and metals
or metal oxides that indicate chiller component wear and/or moisture
in the oil.]
9. Valve and bearing inspection in accordance with manufacturer’s
recommendation.
10. Relief valves (both refrigerant and water) should be checked annually.
Disconnect the vent piping at the valve outlet and visually
inspect the valve body and mechanism for corrosion, dirt, or leakage.
If there are problems, replace the valve; do not attempt to clean or
repair it.
11. Every 6 months, inspect and clean air-cooled condensers as follows:
a. Check unit casing and clear any leaf litter or organic matter in
contact
with the casing. Remove leaves, sticks, and so on, on or in
the unit casing. Check for condition of paint, metal, and so on and
repair as necessary.
b. Check outdoor fans for proper rotation and that the fans do not run
backward when off. Clean and, if needed, balance the fan blades.
c. Lubrication: Typically, fan motors have sealed bearings and require
no lubrication.
d. Inspect condenser coils and clean, if necessary.
12. Perform chemical testing of chilled water at least quarterly. Treat as
needed to ensure proper water chemistry.

kandi younes

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