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DocuSign Envelope ID: 9826C043- 4C32- 49CD- A4CC- DC28ABAB7CE7 <br />3.7 <br />3.8 <br />W* <br />A. <br />B. <br />C. <br />A. <br />B. <br />C. <br />D. <br />E. <br />F. <br />G. <br />A. <br />3.10 <br />A. <br />A <br />3.11 <br />A. <br />SECTION 238000 — TEST AND BALANCE <br />GENERAL PROCEDURES FOR HYDRONIC SYSTEMS <br />Prepare test reports with pertinent design data and number in sequence starting at pump to end of <br />system. Check the sum of branch - circuit flows against approved pump flow rate. Correct variations <br />that exceed plus or minus 5 percent. <br />Prepare schematic diagrams of systems' "as- built" piping layouts. <br />Prepare hydronic systems for testing and balancing according to the following, in addition to the <br />general preparation procedures specified above: <br />1. Open all manual valves for maximum flow. <br />2. Check expansion tank liquid level. <br />3. Check makeup- water - station pressure gage for adequate pressure for highest vent. <br />4. Check flow - control valves for specified sequence of operation and set at indicated flow. <br />5. Set differential - pressure control valves at the specified differential pressure. Do not set at <br />fully closed position when pump is positive - displacement type unless several terminal valves <br />are kept open. <br />6. Set system controls so automatic valves are wide open to heat exchangers. <br />7. Check pump -motor load. If motor is overloaded, throttle main flow - balancing device so motor <br />nameplate rating is not exceeded. <br />8. Check air vents for a forceful liquid flow exiting from vents when manually operated. <br />PROCEDURES FOR HYDRONIC SYSTEMS <br />Measure water flow at pumps. Use the following procedures, except for positive - displacement <br />pumps: <br />1. Verify impeller size by operating the pump with the discharge valve closed. Read pressure <br />differential across the pump. Convert pressure to head and correct for differences in gage <br />heights. Note the point on manufacturer's pump curve at zero flow and verify that the pump <br />has the intended impeller size. <br />2. Check system resistance. With all valves open, read pressure differential across the pump <br />and mark pump manufacturer's head - capacity curve. Adjust pump discharge valve until <br />indicated water flow is achieved. <br />3. Verify pump -motor brake horsepower. Calculate the intended brake horsepower for the <br />system based on pump manufacturer's performance data. Compare calculated brake <br />horsepower with nameplate data on the pump motor. Report conditions where actual <br />amperage exceeds motor nameplate amperage. <br />4. Report flow rates that are not within plus or minus 5 percent of design. <br />Set calibrated balancing valves, if installed, at calculated presettings. <br />Measure flow at all stations and adjust, where necessary, to obtain first balance. <br />1. System components that have Cv rating or an accurately cataloged flow - pressure -drop <br />relationship may be used as a flow- indicating device. <br />Measure flow at main balancing station and set main balancing device to achieve flow that is 5 <br />percent greater than indicated flow. <br />Adjust balancing stations to within specified tolerances of indicated flow rate as follows: <br />1. Determine the balancing station with the highest percentage over indicated flow. <br />2. Adjust each station in turn, beginning with the station with the highest percentage over <br />indicated flow and proceeding to the station with the lowest percentage over indicated flow. <br />3. Record settings and mark balancing devices. <br />Measure pump flow rate and make final measurements of pump amperage, voltage, rpm, pump <br />heads, and systems' pressures and temperatures including outdoor -air temperature. <br />Measure the differential - pressure control valve settings existing at the conclusions of balancing. <br />PROCEDURES FOR VARIABLE -FLOW HYDRONIC SYSTEMS <br />Balance systems with automatic two- and three -way control valves by setting systems at maximum <br />flow through heat - exchange terminals and proceed as specified above for hydronic systems. <br />PROCEDURES FOR MOTORS <br />Motors, 1/2 HP and Larger: Test at final balanced conditions and record the following data: <br />1. Manufacturer, model, and serial numbers. <br />2. Motor horsepower rating. <br />3. Motor rpm. <br />4. Efficiency rating. <br />5. Nameplate and measured voltage, each phase. <br />6. Nameplate and measured amperage, each phase. <br />7. Starter thermal - protection - element rating. <br />Motors Driven by Variable- Frequency Controllers: Test for proper operation at speeds varying from <br />minimum to maximum. Test the manual bypass for the controller to prove proper operation. Record <br />observations, including controller manufacturer, model and serial numbers, and nameplate data. <br />PROCEDURES FOR COOLING TOWERS <br />Shut off makeup water for the duration of the test, and verify that makeup and blowdown systems are <br />fully operational after tests and before leaving the equipment. Perform the following tests and record <br />the results: <br />Reece, Noland & McElrath, Inc. <br />238000-5 <br />Orange County Board of Elections <br />Orange Co., NC 05/04/18 <br />