H14.REV

REFRIGERATION PLANT (ABSORPTION UNITS)

NOTE: FINAL COPY: JANUARY, 1987.

NOTE: THIS SECTION FOR ABSORPTION REFRIGERATION UNITS. PIPING, VALVES AND AUTOMATIC CONTROL DEVICES MUST BE SHOWN ON DRAWINGS FOR THE FOLLOWING: CONDENSER WATER SYSTEM: CONTROLS TO MAINTAIN MINIMUM CONDENSER WATER TEMPERATURE TO ABSORPTION UNITS. HOT WATER UNITS: (1) PIPING, PUMPS AND CONTROLS MUST BE SHOWN IF WATER TEMPERATURE EXCEEDS MAXIMUM LIMIT SET BY MANUFACTURER. (2) UNITS REQUIRING EXTERNAL CAPACITY CONTROL

Part 1 -	GENERAL

1)	WORK INCLUDED

A.	Work in this Section includes providing all labor, materials, equipment and services necessary for a complete and safe installation in accordance with the contract documents and all applicable codes and authorities having jurisdiction for the following

1.	Absorption refrigeration units.

2.	Piping.

3.	Refrigeration plant accessories.

2)	RELATED WORK AND REQUIREMENTS

A.	Requirements of GENERAL CONDITIONS, DIVISION NO. 1 and Section GENERAL PROVISIONS FOR HEATING, VENTILATING AND AIR CONDITIONING WORK apply to all work in this Section

NOTE: EDIT TO SUIT PROJECT REQUIREMENTS. INCLUDE ONLY SECTIONS DIRECTLY AFFECTING WORK OF THIS SECTION

B.	Related work in the following Sections:

1.	PIPING.

2.	STEAM SYSTEM.

3.	CHILLED WATER SYSTEM.

4.	HOT WATER SYSTEM.

5.	CONDENSER WATER SYSTEM.

6.	CONDESER WATER SYSTEM (Field Assembled Towers).

7.	INSULATION.

8.	MOTORS.

9.	MOTOR CONTROLLERS.

10.	AUTOMATIC CONTROL SYSTEMS.

11.	-----.

3)	REFERENCE STANDARDS

A.	ASHRAE Standard is, "Safety Code for Mechanical Refrigeration".

4)	QUALITY ASSURANCE

NOTE: EDIT TO SUIT PROJECT REQUIREMENTS. INCLUDE REFERENCES ONLY DIRECTLY AFFECTING WORK OF THIS SECTION

5)	SUBMITTALS

6)	SUBMITTALS

A.	Refrigeration units: Overall description, unit equipment, dimensioned drawings showing all connection points and required clearances for maintenance and repair, piping arrangement, electric sercice requirements, capacity control valve accessories, control panel, description of controls, safety controls and control wiring diagrams. Performance data shall be certified per ARI standard 550 and shall include steam rate at scheduled inlet pressure or hot water MBH at scheduled GPM and entering temperature, plus leaving temperatures and pressure drops for CHW & CW based on scheduled flow rates and entering conditions

B.	Detailed and dimensioned shop drawings for foundations.

C.	Refrigeration plant accessories.

Part 2 -	PRODUCTS

1)	BASE BID MANUFACTURERS: Carrier Corporation, Trane Company and York Corporation

2)	MATERIALS

A.	Thermostatic air release valves, similar to V.D. Anderson No. 72

NOTE: SINGLE-STAGE UNITS USING STEAM: STEAM PRESSURE AT FLANGE OF UNIT IS NORMALLY 12 PSIG. ADD 2 PSIG FOR PRESSURE DROP THROUGH STEAM CONTROL VALVE. SINGLE-STAGE UNITS USING HOT WATER: WATER TEMPERATURE 270 DEGREES F, FOR HOTTER WATER, PROVIDE BLENDING SYSTEM TYPE CONTROL

3)	CHILLER (REFRIGERATION MACHINE)

TYPE

A.	Single-stage, steam.

B.	Two-stage, steam.

C.	Single-stage, hot water.

D.	Two-stage, hot water.

TYPE

NOTE: SELECT 300 PSIG DESIGN IF REQUIRED.

E.	Shells: Welded construction, in accordance with ASME Requirements for Unfired Pressure Vessels, with removable heads, 150 psig rated

NOTE: FOR COOLING TOWER WATER WITH WATER TREATMENT, FOR OTHER WATER, SUCH AS WELL WATER OR RIVER WATER, OBTAIN MATERIAL SPECIFICATIONS FOR CONDENSER TUBES FROM WATER TREATMENT CONSULTANT. CHECK WITH UNIT MANUFACTURERS

F.	Tubes shall be copper for evaporator, cupro-nickel or copper for absorber, cupro-nickel for concentrator and copper for condenser. Tube sheets shall be steel. Provide individually replaceable tubes rolled and expanded into tube sheets with a maximum tube water velocity of 12 feet per second

G.	Pumps shall be hermetic type, solution and or refrigerant lubricated and cooled, with shutoff valves to permit servicing without opening machine

NOTE: CHECK AND SELECT PROPER CAPACITY CONTROL VALVE.

CAPA

H.	Capacity control valve: Provide pneumatic (electric) type.

I.	Capacity control valve: Provide pneumatic (electric) type, 300 lb flange construction with stainless steel trim

CAPA

J.	Purge system: Provide automatic, self-contained and hermetic, or an external purge compressor

K.	Operating Controls:

1.	Capacity control: Chilled water temperature sensor shall modulate the capacity control valve. Unit shall be capable of automatic modulation down to 10% of scheduled load with scheduled entering water temperatures

NOTE: REVIEW WITH SUPERVISOR:

2.	Start-up steam demand control: Shall limit maximum demand to approximately 105 percent of full load demand

3.	Unit shall be suitable for operation at peak load with entering condenser water down to 65 deg F

L.	Safety controls:

1.	Positive concentration limiter system to automatically prevent crystallization with provision to dilute the solution

2.	Provide means to sense impending crystallization, dilute the machine, and shut it down. Unit shall prevent crystallization in the event of an electrical failure

3.	Chilled water temperature sensor to shut down the unit upon low temperature

4.	Flow switches to prevent unit from starting without proper chilled water and condenser water flow

M.	Control cabinet: factory mounted on unit, complete with all controls, combination fused disconnect and motor controller for all unit-mounted motors, 120 volt transformer with overload protection, relays, fuses, etc. Unit shall be completely factory wired requiring only one electric service connection. Unit shall be prewired to numbered terminal strips and provided with

1.	Purge system controls.

NOTE: COORDINATE WITH ELECTRICAL DEPARTMENT.

2.	Combination fused disconnect switch and magnetic starter type controller for each motor

3.	Automatic dilution cycle timers or time delay relays.

4.	Chilled water thermostat.

5.	Chilled water low temperature control.

6.	Control and interlocking relays.

NOTE: FOR STEAM UNITS WITH HIGH TEMPERATURE CONDENSATE PUMP.

7.	Time delay relay for condensate pump shutoff.

8.	Provide the following on face of panel: start-stop switch, purge switch, pilot lights to indicate operation of unit and purge system, strong solution thermometer if required, disconnect switch operating handles and HOA selector switch

N.	Test pressure shall be not less than 150 percent of design working pressure

NOTE: EDIT ACCESSORIES AS REQUIRED TO SUIT PROJECT.

O.	Accessories:

1.	Factory insulation: Minimum 3/4" foam insulation for all components and surfaces which will sweat. Ratings shall not exceed 25 and 50 respectively.

2.	Vibration isolators: molded neoprene pads.

3.	Marine-type water boxes: Provide for evaporator and condenser. Refer to drawings for pass arrangement

4.	Flow switches: Provide for CHW and CW. Differential pressure type. Flow switches shall be supplied by refrigeration machine supplier, shall be suitable for reliable operation down to 50% of specified flow rate, and shall be set to trip at 50% flow

5.	Refrigerant and oil changes: Manufacturer shall provide full change of all fluids and guarantee such changes for one year

P.	Services:

NOTE: USE ON PROJECTS WHERE EQUIPMENT MAY BE DELIVERED LONG BEFORE IT IS PLACED IN SERVICE. MFGR'S STANDARD WARRANTY TYPICALLY IS 18 MONTHS FROM SHIPMENT OR 12 MONTHS FROM START-UP, WHICHEVER COMES FIRST

1.	Extended warranty: To cover parts and labor for 30 months from shipment or 12 months from start-up.

2.	Factory performance test: Test refrigeration machines in the factory under all scheduled operating conditions. Two weeks prior to tests, advise architect of the time and location of the test. The Owner and his representatives may choose to witness these tests. Perform test in accordance with ARI standard 550, and demonstrate that refrigeration machine performance conforms to the tolerances of that standard

a.	Should the machine fail to meet the specified performace requirements, modify machine as required and retest as required to demostrate specified performance. Any modifications and re-testing shall be done at no additional cost to owner and with no extension in project schedule

b.	Submit modifications for review prior to implementation.

3.	Start-up services: As specified in Part 3 - Installation.

4)	REFRIGERATION PLANT ACCESSORIES.

NOTE: COORDINATE WITH ELECTRICAL & CONTROLS ENGINEERS.

A.	Emergency switches: breakglass type single pole, double throw, suitable for 250 volts, rated at 10 amps at 125 volts AC, surface mounted, aluminum construction with hammer and chain and with red finish. Cover designation shall read, "To Stop Refrigeration". ASCO Model 124302.

Part 3 -	EXECUTION

1)	INSTALLATION

A.	Refrigeration machine: Set machine on vibration isolation pads or other supports as specified. Level machine to within manufacturer's required tolerance

B.	Piping:

C.	Provide flanged piping connections at refrigeration equipment to allow removal of headers and tubes without major removal of piping

D.	Provide as required by manufacturer: external piping, valves, lubricated plug valves (if condenser water by-pass is required) and accessories

1.	Provide valves for condenser cleaning and flushing between condenser and condenser water shutoff valves

NOTE: FOR STEAM OPERATED UNITS ONLY.

2.	Provide condensate return piping with minimum 3/4 inch thermostatic air release valve at outlet of unit. Provide shutoff valve at inlet to air release and pipe discharge to floor drain. Install 1/2 inch piping to release condensate from machine after shutdown from machine side of automatic steam valve to discharge side of trap. Install 15 degree check valve to permit air flow to steam line

2)	FIELD QUALITY CONTROL

A.	Start-up and test shall be supervised by unit manufacturer's representatives and shall include charging with lithium bromide, start-up and field testing. Contractor shall advise Architect two days prior to initiating start-up

B.	The following shall be supplied by the unit manufacturer:

1.	Certification of completion of charging, start-up and field testing and unit ready for proper operation

2.	Services of competent instructor for two (2) 7 hour days, not necessarily continuous and over a one (1) year period, to instruct Owner's personnel in proper operation and maintenance of equipment