Carrier 16JT Series Start Up & Operation Manual

Carrier 16JT Series Start Up & Operation Manual Manual pdf 34 page image

Solution or Refrigerant Sampling — (See precau-tions pertaining to handling lithium bromide solution asdescribed in Solution and Refrigerant Charging section,page 21.)Take solution or refrigerant samples from the pump serv-ice valve while the pump is operating.Before taking a sample for analysis or absorber loss de-termination, be sure machine is operating with steady loadand that Cycle-Guard™ valve has not been energized within10 minutes prior to sampling.Attach a hose adapter to the pump service valve. Do notuse copper or brass fittings when taking samples for analy-sis; copper oxide can form and contaminate samples.The solution pump normally discharges at above atmo-spheric pressure, but the refrigerant pump discharges at avacuum, so the respective sampling procedures aredifferent.SOLUTION SAMPLE1. Fill a length of flexible tubing with water and connectone end to the hose adapter. Place the free end in a con-tainer of water. Be sure end is submerged (Fig. 29).2. Open valve slightly. When container water level rises, waitseveral seconds to purge the water from the tube. Thenremove tube end from water and fill sample container.3. Turn off service valve and remove hose and adapter.REFRIGERANT SAMPLE (Fig. 30)1. Connect a clean, empty vacuum container to the pumpservice valve with a length of flexible hose.2. Connect a vacuum pump to the vacuum container with aflexible hose and isolation valve.3. Pull a deep vacuum on the container and close the iso-lation valve.4. Open the service valve slightly to drain refrigerant sampleinto the container.5. Turn off service valve, remove hose and adapter, and dis-connect vacuum pump.Solution Analysis — Laboratory analysis of a solutionsample gives indication of change in solution alkalinity anddepletion of inhibitor, and may indicate the degree of ma-chine leak tightness.Have the solution analyzed at least once a year or when-ever there is an indication of a noncondensable problem. Takethe sample from the solution pump service valve while themachine is running (see Solution or Refrigerant Samplingsection, this page). The sample concentration should be be-tween 58% and 62% by weight for best results.Solution analysis should be done by an approved lab-oratory. The analysis interpretation and the adjustment rec-ommendations should be made by a trained absorptionspecialist.Inhibitor — The initial charge of lithium bromide in-cludes a lithium chromate inhibitor. The inhibitor is used inconjunction with alkalinity control to minimize the amountof hydrogen normally generated within the machine. Exces-sive hydrogen generation interferes with machine perfor-mance.The inhibitor is gradually depleted during machine opera-tion and occasional replenishment is necessary. Solution al-kalinity also changes over a period of time and must be ad-justed (see Solution Analysis, on this page).IMPORTANT: Altering the inhibitor or using solutionand internal surface treatments not specified by the equip-ment manufacturer may result in performance deterio-ration and damage to the absorption machine.Fig. 29 — Adding or Removing FluidFig. 30 — Refrigerant Sampling Technique34