Carrier 16JT Series Start Up & Operation Manual

Carrier 16JT Series Start Up & Operation Manual Manual pdf 25 page image

INITIAL START-UPThe following start-up procedures are based on a semi-automatic system in which all pumps energize when the start-stop switch is placed in the START position.Preliminary Check — Check the operation of auxil-iary equipment and status of system before starting the ab-sorption machine.PREPARATION1. Add the amount of octyl alcohol specified in Table 5 throughthe solution pump service valve. (Refer to MaintenanceProcedures, Adding Octyl Alcohol section, page 35.) Donot allow air to be drawn into machine.2. Supply power to control panel, chilled water, and con-densing water pumps. Open manual steam supply valves,chilled water valves, and cooling water valves.3. Place the capacity control and Cycle-Guard™ settings inAUTO. position and Local/Remote switch in the Localposition. Depress the Start button.4. When the solution is warm (strong solution below 140 F[60 C]), place the capacity control auto.-man. button inMANUAL position and depress the down arrow until valveis fully closed.5. Determine the machine absorber loss as described in Main-tenance Procedures, Absorber Loss Determination sec-tion, page 31.If absorber loss is 5° F (2.8° C) or less, place capacitycontrol valve on AUTO. and allow machine to operate.If the absorber loss is greater than 5° F (2.8° C), evacuatethe machine (see Maintenance Procedures, Machine Evacu-ation section, page 33) to remove any noncondensablesthat might prevent normal operation. As an alternate pro-cedure, limit steam pressure to keep strong solution tem-perature under 140 F (60 C) and allow the purge to re-move the noncondensables.After the absorber loss has been reduced to below 5° F(2.8° C) by either of the above procedures, place ma-chine on automatic operation, with capacity control but-ton in AUTO. position and steam pressure normal. Thepurge will evacuate the machine to the normal absorberloss of 2° F (1.1° C) or less.Table 5 — Octyl Alcohol Initial Charge16JT OCTYL ALCOHOLGal L810,812,814 1 3.8816,818,821,824 2 7.6828,832,836 2 7.6841,847,854 3 11.4857,865,873 4 15.2880 5 19.0080 6 22.7080L,090 7 26.5090L,100 8 30.3100L,110 10 37.9110L,120 12 45.5120L,135 14 53.1135L,150 16 60.6150L 18 68.2Final Adjustment of Capacity Controls — Al-low the chiller to operate long enough with a fairly stableload for the system to reach equilibrium. Verify that the chilledwater temperature is close to the set point and the system isstable (with little capacity control valve cycling or search-ing). See Initial Control Checkout and Adjustment, CheckCapacity Control Operation section, page 23, for set pointand control adjustment procedures.The controller tuning parameters have been factory-configured for control stability with typical applications.However, if necessary, the parameters can be adjusted forimproved stability with either manual or automatic recon-figuration procedures.WITH THE MANUAL PROCEDURE, the configuration forproportional band, rate, and reset are adjusted until the sys-tem is stable.WITH THE AUTOMATIC PROCEDURE, the controller hasAUTOTUNE capability to automatically calculate and ad-just a particular cooling system’s optimal tuning parameters.See the UDC 3000 Unviersal Digital Controller productmanual for specific description, configuration, operation, andtroubleshooting information.Final Refrigerant Charge Adjustment — The ad-justment should be made after:1. Machine is operating with stable temperatures at 40 to100% of full load.2. Absorber loss is 3° F (1.7° C) or less.3. Refrigerant specific gravity is 1.02 or less.The refrigerant charge is adjusted so that the Cycle-Guard™ system can limit maximum solution concentrationand avoid solution crystallization. Proceed as follows:1. Place Cycle-Guard Switch (43RV) in the AUTO. posi-tion. Then, if the Cycle-Guard valve remains off at least10 minutes, proceed to Step 2. If not, gradually reducethe load on the chiller (to reduce the solution concentra-tion) until the Cycle-Guard valve remains off. The valvewill be energized when the refrigerant high level light isON.2. Remove a solution sample from the solution pumpservice valve and measure the specific gravity andtemperature.3. Locate the intersection point of the specific gravity andtemperature values on equilibrium diagram (Fig. 22A or22B). Read down from this point to the solution concen-tration scale to determine the percent lithium bromide byweight in the weak solution.4. Determine the approximate percent of full load on the ma-chine by comparison of chilled water temperature spread,and flow in relation to design. Enter Table 6 at this per-cent load and find the corresponding weak solution con-centrations required for refrigerant charge adjustment.Table 6 — Weak Solution Concentrations forAdjusting Refrigerant ChargeREFRIGERANTLEVELPERCENT LOAD ON MACHINE100 90 80 70 60 50 40Weak Solution Concentration (%)High 60 60.4 60.8 61.2 61.6 61.9 62.2Mid 58 58.4 58.7 59.1 59.4 59.8 60.1NOTE: Concentrations listed in Table 6 are for nominal design con-ditions. For special design conditions, obtain the special concentra-tion settings from the factory.5. Adjust machine operating conditions until machine op-erates with stable temperatures at either of the weak so-lution concentrations (±0.1%) listed in Table 6 under theselected percent load.To increase the concentration:a. Increase the load.b. Lower chilled water temperature (set point adjuster set-ting).c. Raise condensing water temperature (or throttle con-densing water flow).After adjusting conditions, repeat Steps 2 and 3 to verifysolution concentration.25