Guide Specifications, Compressor, Lubrication System

Guide Specifications

FORM 160.81-EG1

GENERAL

Furnish and install where indicated on the drawings YORK MAXE Rotary Screw Liquid Chilling Unit(s). Each

unit shall produce a capacity of			tons, cooling
GPM of	from	°F to	°F when supplied
with	_____ GPM of condenser water at
°F. Power input shall not exceed			kW with an IPLV
(NPLV) of		_____. The evaporator shall be
selected for		ft2 °F hr/BTU fouling factor and a
maximum liquid pressure drop of			ft. Water side

shall be designed for 150 or 300 psig working pressure.

The condenser shall be selected for fouling factor and maximum liquid pressure drop of ____ ft.

Water side shall be designed for 150 or 300 psig work- ing pressure. Power shall be supplied to the compres-

sor motor at volts – 3-phase – (60)(50) Hertz and controls at 115 volts –1-phase – (60)(50) Hertz.

– (or) –

Furnish and install where indicated on the drawings YORK MAXE Rotary Screw Liquid Chilling Unit(s). Each


unit shall produce a capacity of			kW, cooling		L/S
of	from	°C to	°C when supplied with
____ L/S of condenser water at			°C. Power input
shall not exceed		kW with an IPLV (NPLV) of
____. The evaporator shall be selected for				M2 °C/W

fouling factor and a maximum liquid pressure drop of

___ kPa. Water side shall be designed for 1034 or 2068 kPa working pressure. The condenser shall be selected


for	M2 °C/W fouling factor and maximum liquid
pressure drop of		kPa. Water side shall be designed

for 1034 or 2068 kPa working pressure. Power shall be supplied to the compressor motor at volts – 3-phase

– 50 Hz and controls at 115 volts – 1-phase – 50 Hz.

Performance shall be certified or rated in accordance with the latest edition of ARI Standard 550/590-98 as applicable. Only chillers that are listed in the ARI Certi- fication Program for Water Chilling Packages using the vapor compression cycle are acceptable.

Each unit shall be completely factory packaged includ- ing evaporator, condenser, subcooler, oil separator, com- pressor/motor, lubrication system, OptiView Control Center, Solid State Starter (optional), refrigerant isola- tion valves (optional) and all interconnecting piping and wiring. The factory package shall consist of a “Leaktight”

design, with no pipe thread connections that can loosen and leak over time. All units shall ship with a full charge of refrigerant HFC-134a and oil. Alternatively, the chiller shall be shipped with the compressor, control panel and oil separator removed (Form 3) or also with the shells separated (Form 7) to allow rigging into the equipment room. All units that ship disassembled shall be assembled and factory run tested prior to disassembly and shipment).

Compressor

The compressor shall be a rotary-screw type. The com- pressor housing shall be of cast iron, precision machined to provide minimal clearance for the rotors. The rotors shall be manufactured from forged steel and use asym- metric profiles operating at a maximum speed of (3570 RPM/60 Hz) (2975 RPM/50 Hz). The compressor shall incorporate a complete anti-friction bearing design to re- duce power and increase reliability; four separate cylin- drical roller bearings to handle radial loads; and two 4- point angular contact ball bearings to handle axial loads. A check valve shall be incorporated in the compressor housing to prevent rotor backspin during shutdown.

Capacity control shall be achieved by use of a slide valve to provide fully modulating control from 100% to 20% of full-load. The slide valve shall be actuated by system differential pressure, controlled by external so- lenoid valves through the OptiView Control Center. The unit shall be capable of operating with lower tempera- ture cooling tower water during part-load operation in accordance with ARI Standard 550/590.

Lubrication System

An adequate supply of oil shall be available to the com- pressor at all times. During start-up and coastdown, this shall be achieved by oil reservoirs in the compressor. During operation, oil shall be delivered by positive sys- tem pressure differential.

All chillers shall be provided with a single oil filter hous- ing with isolation valves. An optional dual filter is avail- able which allows immediate switching from one filter to the other, eliminating downtime during filter changes. The off-line oil filter must be capable of being changed during chiller operation. The chiller shall ship with a 3 micron absolute oil filter, (two filters for dual filter op- tion) maintaining a clean oil system and ensuring supe- rior compressor life.

36	YORK INTERNATIONAL