Operating instructions

1. Vibration eliminators to reduce vibration and noise transmission to the building.
2. Shutoff valves are required to isolate the unit from the piping system during unit servicing.
3. Manual or automatic air vent valves at the high points of the system. Drains must be installed
at the lowest points in the system.
4. Adequate system water pressure must be maintained (expansion tank or regulating valve).
5. Temperature and pressure indicators located at the unit are required to aid in unit servicing.
6. A strainer or other means of removing foreign matter from the water before it enters the pump
must be installed. Place the strainer far enough upstream to prevent cavitation at the pump
inlet (consult pump manufacturer for recommendations). The use of a strainer will prolong
pump life and keep system performance up.
7. A strainer
must be installed in the water line before the inlet of the evaporator. This will help
prevent foreign material from entering and decreasing the evaporator performance.
8. If the unit is used as a replacement chiller, flush the system thoroughly before unit
installation. Regular water analysis and chemical water treatment for the evaporator loop is
recommended immediately at equipment start-up.
9. The total water volume in the system should be sufficient to prevent frequent “on-off”
cycling. Turnover rate should not be less than 4 minutes for normal variable cooling loads.
10. When glycol is added to the water system for freeze protection, the refrigerant suction
pressure will be lower, cooling performance less, and water side pressure drop greater. If the
percentage of glycol is high, or if propylene is used instead of ethylene glycol, the added
pressure drop and loss of performance could be substantial. When Glycol or Ice are selected
as Unit Mode, the MicroTech controller will automatically reset the available range for the
Leaving Water Temperature, Freezestat and Evaporator Pressure settings.
Reset the freezestat setting to approximately 4 to 5 degrees F (2.3 to 2.8 degrees C) below the
leaving chilled water setpoint temperature. See the section titled “Glycol Solutions” for
additional information concerning glycol.
11. Perform a preliminary leak check before insulating the piping and filling the system.
12. Piping insulation should include a vapor barrier to prevent condensation and possible damage
to the building structure from water dripping.
Figure 17, AGZ 075BM – AGZ 130BM, Typical Field Evaporator Water Piping
INLET
THERMOWELL
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IMM ACZ/AGZ-4 ACZ / AGZ-BM 15