2525 W CASINO RD BASE FILE 2025-01-03

installation INSTALLATION OF BLOWER MODELS(BA/BAE UNITS) To Install(Figure 6): Determining Blower Speed 1. Remove and discard the motor tie down strap and the The drive assembly and motor on all gas-fired blower unit shipping block beneath the adjustable foot on the motor heaters are factory assembled.The adjustable motor pulley base. (Not used on all models.) has been pre-set to permit operation of this unit under aver- MOTOR age conditions of air flow and without any external static MOUNTING ADJ.(MOVABLE FACE SHEAVE pressure. The motor pulley should be adjusted as required BRACKET (MOVABLE FACE p p y � q TO OUTSIDE) when the unit is to be operated at other than average air flows and/or with external static pressures. Adjustment must always be within the performance range shown on pages 18 and 19 and the temperature rise range shown on the unit's rating plate. To determine the proper blower speed and drive pulley set- ting,the conditions under which the unit is to operate must be known.If the blower unit is to be used without duct work,nozzles M or filters, the only criteria for determining the pulley setting X BELT TENSION Or speed is the amount of air to be delivered. The ADJUSTING and blower s P � '.�,,' � u� SCREW performance tables for blower models are shown on pages TIE DOWN STRAP 18 and 19.As an example,a model BA 350 unit,operating in AND BLOCK FOR a free blow mode, that is, no duct work, filters, etc., and IS t0 �,„ + SHIPPING ONLY deliver an air volume of 4537 cfm(cfm=cubic feet of air)requires that the unit be supplied with a 11/2 hp motor,a C23 drive and, s OWove the drive pulley must be set at 2 turns open to achieve a blower speed of 625 rpm(see performance table for units without blower CONTROL JUNCTION enclosure, page 18). See"Blower Adjustments"for setting of TRANSFORMER BOX drive pulley turns open. Figure 5 If a blower unit is to be used with ductwork and/or filters, Blower Model Installation nozzles, etc., the total external static pressure under which the unit is to operate, and the required air volume must be 2. Adjust motor adjusting screw for a belt deflection of ap- known before the unit can be properly adjusted.Any device proximately 3/4 with five pounds of force applied midway added externally to the unit, and which the air must pass between the sheaves (refer to Figure 6a). Since the belt through, causes a resistance to air flow. This resistance is tension will decrease dramatically after an initial running called static pressure loss. The total of the external static period, it is necessary to periodically re-check the tension pressure losses must be determined before adjusting the to assure continual proper belt adjustment.Excessive tension blower speed. will cause bearing wear and noise. If Modine filters are used, the expected pressure drop 3. The blower bearings are lubricated for life; however, through the filters can be determined from the pressure drop before initial unit operation the blower shaft should be curves shown on page 14. If Modine supplied discharge lubricated at the bearings with SAE 20 oil.This will reduce nozzles are used,the expected pressure drop of the nozzles initial friction and start the plastic lubricant flowing. can be found footnoted at the bottom of page 14. If filters, 4. Make electrical connections according to the wiring nozzles,or ductwork is to be used with the unit,and they are diagram. not supplied by Modine, the design engineer or installing contractor must determine the pressure drop for the exter- 5. Check rotation of the blower. Motor should be in clock- nally added devices,or ductwork,to arrive at the total static wise rotation when facing motor pulley.If rotation is incor- pressure under which the unit is to operate. rect,correction should be made by interchanging wiring Once the total static pressure,and the required cfm(air volume) within the motor. See wiring diagram on the motor. are known,the operating speed of the blower can be determined 6. The actual current draw of the motor should be deter- and the correct drive pulley adjustments made.As an example, mined. Under no condition should the current draw if a model BA 350 is to be used with a Modine supplied blower exceed that shown on the motor rating plate. enclosure, Modine supplied filters,and is attached to ductwork 7 It is the installer's responsibility to adjust the motor pulley supplied by others, and the unit is to move 4537 cfm of air,the to the s provide filter pressure drop would be approximately 0.78" W.C. (from p pacified blower performance as listed on Pages 18 and 19, for blower settings different from the filter pressure drop curves on page 14).Assuming the ductwork factory set performance. The drive number on the unit has been designed fora 0.15" W.C. pressure drop, the total external static pressure the unit is to operate against would be maybe identified by referring to the Power Code number on the serial plate of the unit (see page 27 for model 0.78"W.C.+0.15"W.C.or 0.23"W.C.Entering the performance table on page 19(units with blower enclosure)for a BA 350,at number nomenclature) and matching that number with those shown on page 25.From the listing the drive number 4537 cfm and 0.3"W.C.static pressure, it is seen that the unit will require a 2 hp motor using a C19 drive,and the drive pulley can be determined. should be set at a 112 turns open to achieve a blower speed of 8. Blower sheave and motor sheave should be measured to 785 rpm. See "Blower Adjustments"for setting of drive pulley assure correct drive is on unit. Refer to page 25 for drive turns open. sizes. Page 7