York SUNLINE DCG Series Installation Manual

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York SUNLINE DCG Series Installation Manual Manual pdf 38 page image

290699-YIM-B-060738 Unitary Products GroupPHASINGCheck for proper compressor rotation. If the blower orcompressors rotate in the wrong direction at start-up,the electrical connection to the unit is misphased.Change the incoming line connection phasing to obtainproper rotation. (Scroll compressors operate in onlyone direction. If the scroll is drawing low amperage,has similar suction and discharge pressures, or pro-ducing a high noise level, the scroll is misphased).SUPPLY AIR BLOWERSThese blowers have either 3-speed direct drive motors,or single speed motors equipped with a belt drive. Beltdrive units have a variable pitch pulley that allows theblower speed to be adjusted.CHECKING SUPPLY AIR CFMThe RPM of the supply air blower will depend on therequired CFM, the unit accessories or options and thestatic resistances of both the supply and the return airduct systems. With this information, the motor speedtap (direct drive) or the motor pulley number of turnsopen (belt drive) can be determined from the BlowerPerformance Data Tables.Note the following:1. The supply air CFM must be within the limitationsshown in the Unit Application Data Table 1.2. Pulleys can be adjusted in half turn increments.3. The tension on the belt should be adjusted asshown in the Belt Adjustment Figure 16.TABLE 26: STATIC RESISTANCES1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 30000.07 0.08 0.09 0.11 0.13 0.15 0.17 0.20 0.23 0.26 0.307-15KW 0.04 0.05 0.06 0.07 0.08 0.10 0.12 0.14 0.16 0.19 0.2220-30KW 0.06 0.07 0.08 0.09 0.11 0.13 0.15 0.17 0.20 0.23 0.260.06 0.07 0.08 0.09 0.10 0.11 0.12 0.14 0.16 0.19 0.220.08 0.10 0.12 0.14 0.16 0.18 0.20 0.23 0.26 0.29 0.32COOLING ONLY2RESISTANCE, IWGCFMDESCRIPTIONECONOMIZER1 3BOTTOM DUCT CONNECTIONS1ELECTRICHEATERS11. Deduct these resistance values from the available external static pressure shown in SUPPLY AIR BLOWER PERFORMANCE Tables.3. The pressure through the economizer is greater for 100% outdoor air than for 100% return air. If the resistance of the return airduct system is less than 0.25 IWG, the unit will deliver less CFM during full economizer operation.2. Add these resistance values to the available static resistance values on SUPPLY AIR BLOWER PERFORMANCE Tables.Scroll compressors require proper rotation tooperate correctly. Do not change the internalwiring to make the blower, condenser fans, orcompressor rotate correctly. Change theincoming power to the main terminal block toobtain proper rotation.FIGURE 16 - BELT ADJUSTMENTLoosen nuts (A) (top and bottom).Adjust the tension by turning bolt (B).Never loosen nuts (C) from each other.Use a belt tension checker to apply a perpendicular force to be one belt at themidpoint of the span as shown. The deflection force should be applieduntil a specific deflection distance of 4mm (5/32") is obtained. To determinethe deflection distance from normal position, use a straight edge fromsheave to sheave as a reference line. The recommended deflection forceis as follows:1.2.3.4.PROCEDURE FOR ADJUSTING BELT TENSION:Tension new belts at the max. deflection force recommended for the beltsection. Check the belt tension at least two times during the first 24 hours ofoperation. Any re-tensioning should fall between the min. and max.deflection force values.5. After adjusting, re-tighten nuts (A).*Never Loosen(A) (C)*(B)SPAN LENGTHDEFL FORCE