Evacuation or Pump-Out Systems

noncondensable gases from refrigeration system and condense, separate, and

return to system refrigerant present. Provide an oil separator, if

required by manufacturer. Purge systems shall provide a warning to signal

operator at occurrence of excessive purging, indicating abnormal air

leakage into unit. Purge systems shall not discharge to occupied areas, or

create a potential hazard to personnel.

2.1.1.6

Evacuation or Pump-Out Systems

When a positive refrigerant is used and basic chiller unit will not permit

pumpdown storage and isolation of entire charge within basic unit, provide

a manually started and stopped evacuation or pump-out system, consisting of

a condensing unit and a receiver of sufficient capacity to store entire

refrigerant charge of largest water-chilling system or unit. When designed

to permit pumpdown of entire refrigerant charge and isolation of entire

refrigerant charge within basic unit, a separate evacuation or pump-out

shall not be required. Receivers shall be provided with rupture members

and dual relief valves, piping, and controls so that the evacuation or

pump-out system may be provided without temporary piping or wiring.

2.1.1.7

Controls, Control Panels, and Gages

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NOTE: Specify required time delay for type and size

of unit after consulting current literature.

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NOTE: Include sentence in brackets if centrifugal

chillers are specified.

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Provide an automatic capacity-reduction system for stable operation from

100 to 10 percent of full load capacity. Provide modulating, chilled-water

controls with adjustable throttling range, a means of calibration, and a

means of adjusting chilled-water temperature control point. Provide a time

delay of not less than [_____] minutes to prevent compressor restart when a

compressor is shut down by the operating controls. Provide a demand

limiter to minimize amperage draw. [Provide controls to restart chiller

automatically if power is interrupted for three seconds or less.] Provide

a control panel complete with compressor operating control, start-stop

switch, and the following gages and protective devices:

a.

Gages:

(1)

Evaporator pressure

(2)

Condenser pressure

(3)

Oil pump pressure

(4)

Elapsed running time meter

b.

Protection Devices With Manual Reset:

(1)

Low oil temperature lockout

(2)

Low refrigerant temperature cutout

SECTION 15601N

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