York R134A manual Guide Specifications – continued, ACCESSORIES and OPTIONS

Guide Specifications – continued

atures, ambient, lead compressor identification, clock and schedule, (variable) out of range, remote input indication, chilled liquid reset setpoint, and history data for last ten shutdown faults. Compressor suc- tion, discharge, and oil pressures and temperatures, suction and discharge superheats, percent of full- load, operating hours, starts, and anti-recycle timer status. Status Messages for manual override, unit switch off, compressor run, run permissive, remote controlled shut down, no cooling load, daily/holiday shut down, anti-recycle timer.

E.Predictive Control Points: Unit controls shall avoid safety shutdown when operating outside design conditions by optimizing the chiller controls and cool- ing load output to stay online and avoid safety limits being reached. The system shall monitor the follow- ing parameters and maintain the maximum cooling output possible without shutdown of the equipment: motor current, suction pressure and discharge pres- sure.

F.System Safeties: Shall cause individual compressor systems to perform auto-reset shut down; manual reset required after the third trip in 90 minutes. Includes: high discharge pressure or temperature, low suction pressure, high / low motor current, high motor temperature, high pressure switch, high / low differential oil pressure, high oil temperature, low suction superheat, critical sensor malfunction, low or high current, phase loss/single phase power, overload of motor windings, and low voltage.

G.Unit Safeties: Shall be automatic reset and cause

compressors to shut down if: high or low ambient, low leaving chilled liquid temperature, under voltage, and flow switch operation. Contractor shall provide flow switch and wiring per chiller manufacturer re- quirements.

H.Manufacturer shall provide any controls not listed above, necessary for automatic chiller operation. Mechanical Contractor shall provide field control wiring necessary to interface sensors to the chiller control system.

2.07 ACCESSORIES and OPTIONS

Some accessories and options supersede standard product features. Your Johnson Controls representative will be pleased to provide assistance.

A. Sound Reduction

1. Provide the following options as required to

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meet scheduled sound performance data at all load points.

a. Normal speed fans and unlined compressor enclosure. (Factory Mounted)

b. Two-speed fans and acousticallly lined enclo- sure. (Factory Mounted)

c.Sound power octave band data, dB per ARI standard 70 and IAW ISO3744 at 35°C ambient and 7°C leaving chilled water.

2.Provide optional control input to limit sound out- put of the chiller based on time of day. Shall be programmable at the chiller panel or controlled remotely via signal (4-20mA or 0-10 VDC) from BAS system. Chillers without this feature shall be provided with the necessary sound attenuation to meet the scheduled sound performance data at all load points.

B.Power Supply/Connections:

1.Circuit breaker is optional at point of incoming single point connection to provide disconnecting means AND be sized to provide the motor branch circuit protection, short circuit protection and ground fault protection for the motor branch-circuit conductors, the motor control apparatus and the motors. Circuit breaker shall be equipped with lockable operating handle that shall extend through power panel door so that power may be discon- nected without opening any panel doors.

C.Condenser Coil Environmental Protection:

1.PRE-COATED FIN CONDENSER COILS –

The air-cooled condenser coils are constructed of epoxy-coated aluminum fins.

2.COPPER FIN – Provide condenser coils with cop- per fins in lieu of aluminum fins.

3.POST-COATED EPOXY DIPPED CONDENSER COILS – The unit is built with dipped-cured con- denser coils.

D.Protective Chiller Panels (Factory Mounted):

1.Louvered Panels (condenser coils only): Painted steel to match unit panels, over external condenser coil faces.

2.Wire Panels (full unit): Heavy gauge, welded wire mesh, coated to resist corrosion, to protect con- denser coils from incidental damage and restrict unauthorized access to internal components.

3.Louvered Panels (full unit): Painted steel to match unit panels, to protect condenser coils from inci- dental damage, visually screen internal compo- nents, and prevent unauthorized access to internal

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