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DocuSign Envelope ID: 9826C043- 4C32- 49CD- A4CC- DC28ABAB7CE7 <br />SECTION 239500 - MULTI - INDOOR VRV SYSTEM <br />With each reading, the compressor capacity (INV frequency) shall be con- <br />trolled to eliminate deviation from target value. <br />2. The inverter driven compressors in the condensing unit shall be of highly <br />efficient reluctance DC (digitally commutating), hermetically sealed scroll <br />"G- type" or "J- type ". <br />3. Neodymium magnets shall be adopted in the rotor construction to yield a <br />higher torque and efficiency in the compressor instead of the normal fer- <br />rite magnet type. At complete stop of the compressor, the neodymium <br />magnets will position the rotor into the optimum position for a low torque <br />start. <br />4. The capacity control range shall be as low as 10% to 100 %. <br />5. Each compressor shall be equipped with a crankcase heater, high pres- <br />sure safety switch, and internal thermal overload protector. <br />6. Oil separators shall be standard with the equipment together with an intel- <br />ligent oil management system. <br />7. The compressor shall be spring mounted to avoid the transmission of vi- <br />bration eliminating the standard need for spring insolation <br />8. Compressor configurations <br />Tonnage <br />Number of <br />Compressors <br />Compressor Types <br />6 <br />1 <br />Inverter controlled <br />8 <br />1 <br />Inverter controlled <br />10 <br />1 <br />Inverter controlled <br />12 <br />2 <br />All inverter controlled <br />14 <br />2 <br />All inverter controlled <br />16 <br />2 <br />All inverter controlled <br />18 <br />2 <br />All inverter controlled <br />20 <br />2 <br />All inverter controlled <br />22 <br />3 <br />All inverter controlled <br />24 <br />4 <br />All inverter controlled <br />26 <br />4 <br />All inverter controlled <br />28 <br />4 <br />All inverter controlled <br />30 <br />3 <br />All inverter controlled <br />32 <br />4 <br />All inverter controlled <br />34 <br />5 <br />All inverter controlled <br />9. In the event of compressor failure the remaining compressors shall con- <br />tinue to operate and provide heating or cooling as required at a propor- <br />tionally reduced capacity. The microprocessor and associated controls <br />shall be designed to specifically address this condition for single module <br />and manifolded systems <br />10. In the case of multiple condenser modules, conjoined operation hours of <br />the compressors shall be balanced by means of the Duty Cycling Func- <br />tion, ensuring sequential starting of each module at each start /stop cycle, <br />completion of oil return, completion of defrost or every 8 hours. When <br />connected to a central control system sequential start is activated for all <br />system on each DIII network <br />F. Electrical: <br />Reece, Noland & McElrath, Inc. 239500-10 Orange County Board of Elections <br />Orange Co., NC 05/04/18 <br />