Carrier AQUAZONE 50HQL072-120 Installation, Start-up And Service Instructions Manual

Carrier AQUAZONE 50HQL072-120 Installation, Start-up And Service Instructions Manual Manual pdf 34 page image

34An alternative method is to install a flow control device.These devices are typically an orifice of plastic material de-signed to allow a specified flow rate that are mounted on theoutlet of the water control valve. Occasionally these valvesproduce a velocity noise that can be reduced by applyingsome back pressure. To accomplish this, slightly close theleaving isolation valve of the well water setup.Flushing — Once the piping is complete, final purgingand loop charging is needed. A flush cart pump of at least1.5 hp is needed to achieve adequate flow velocity in theloop to purge air and dirt particles from the loop. Flush theloop in both directions with a high volume of water at a highvelocity. Follow the steps below to properly flush the loop:1. Verify power is off.2. Fill loop with water from hose through flush cart be-fore using flush cart pump to ensure an even fill. Donot allow the water level in the flush cart tank to dropbelow the pump inlet line to prevent air from fillingthe line.3. Maintain a fluid level in the tank above the return teeto avoid air entering back into the fluid.4. Shutting off the return valve that connects into theflush cart reservoir will allow 50 psi surges to helppurge air pockets. This maintains the pump at 50 psi.5. To purge, keep the pump at 50 psi until maximumpumping pressure is reached.6. Open the return valve to send a pressure surge throughthe loop to purge any air pockets in the piping system.7. A noticeable drop in fluid level will be seen in theflush cart tank. This is the only indication of air in theloop.NOTE: If air is purged from the system while using a 10 in.PVC flush tank, only a 1 to 2 in. level drop will be noticedsince liquids are incompressible. If the level drops morethan this, flushing should continue since air is still beingcompressed in the loop. If level is less than 1 to 2 in.,reverse the flow.8. Repeat this procedure until all air is purged.9. Restore power.Antifreeze may be added before, during or after theflushing process. However, depending on when it is addedin the process, it can be wasted. Refer to the Antifreeze sec-tion for more detail.Loop static pressure will fluctuate with the seasons. Pres-sures will be higher in the winter months than during thewarmer months. This fluctuation is normal and should beconsidered when charging the system initially. Run the unitin either heating or cooling for several minutes to conditionthe loop to a homogenous temperature.When complete, perform a final flush and pressurize theloop to a static pressure of 40 to 50 psi for winter months or15 to 20 psi for summer months.After pressurization, be sure to remove the plug from theend of the loop pump motor(s) to allow trapped air to bedischarged and to ensure the motor housing has been flood-ed. Be sure the loop flow center provides adequate flowthrough the unit by checking pressure drop across the heatexchanger.Antifreeze — In areas where entering loop temperaturesdrop below 40 F or where piping will be routed through ar-eas subject to freezing, antifreeze is needed.Alcohols and glycols are commonly used as antifreezeagents. Freeze protection should be maintained to 15 Fbelow the lowest expected entering loop temperature. Forexample, if the lowest expected entering loop temperature is30 F, the leaving loop temperature would be 22 to 25 F.Therefore, the freeze protection should be at 15 F (30 F –15 F = 15 F).Calculate the total volume of fluid in the piping system.See Table 22. Use the percentage by volume in Table 23 todetermine the amount of antifreeze to use. Antifreeze con-centration should be checked from a well mixed sample us-ing a hydrometer to measure specific gravity.FREEZE PROTECTION SELECTIONThe 30 F FP1 fac-tory setting (water) should be used to avoid freeze damageto the unit.Once antifreeze is selected, the JW3 jumper (FP1)should be clipped on the control to select the low tempera-ture (antifreeze 13 F) set point to avoid nuisance faults.Table 22 — Approximate Fluid Volume (gal.)per 100 Ft of PipeLEGENDNOTE: Volume of heat exchanger is approximately 1.0 gallon.Table 23 — Antifreeze Percentages by VolumeCooling Tower/Boiler Systems — These systemstypically use a common loop maintained at 60 to 90 F. Theuse of a closed circuit evaporative cooling tower with asecondary heat exchanger between the tower and the waterloop is recommended. If an open type cooling tower isused continuously, chemical treatment and filtering will benecessary.Ground Coupled, Closed Loop and PlateframeHeat Exchanger Well Systems — These systemsallow water temperatures from 30 to 110 F. The externalloop field is divided up into 2 in. polyethylene supply and re-turn lines. Each line has valves connected in such a way thatupon system start-up, each line can be isolated for flushingusing only the system pumps. Air separation should be locat-ed in the piping system prior to the fluid re-entering the loopfield.To avoid possible injury or death due to electrical shock,open the power supply disconnect switch and secure it inan open position before flushing system. IMPORTANT: All alcohols should be pre-mixed andpumped from a reservoir outside of the building or intro-duced under water level to prevent alcohols from fuming.PIPE DIAMETER (in.) VOLUME (gal.)Copper 1 4.11.25 6.41.5 9.2Rubber Hose 1 3.9Polyethylene 3 /4 IPS SDR11 2.81 IPS SDR11 4.511 / 4 IPS SDR11 8.01 /2 IPS SDR11 10.92 IPS SDR11 18.011 / 4 IPS SCH40 8.311 / 2 IPS SCH40 10.92 IPS SCH40 17.0IPS — Internal Pipe SizeSCH — ScheduleSDR — Standard Dimensional RatioANTIFREEZEMINIMUM TEMPERATURE FORFREEZE PROTECTION (F)10 15 20 25Methanol (%) 25 21 16 10100% USP Food GradePropylene Glycol (%) 38 30 22 15Ethanol (%) 29 25 20 14