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McQuay IM 777-1

21

Service and Maintenance

passes around the sheave (pitch diameter). Calculate fan speed 
from the motor nameplate rpm.

VM and VP Variable Pitch Key Type Sheaves

Mounting:

1

Mount all sheaves on the motor or driving shaft with the 
setscrews

A

 toward the motor.

2

Verify that both driving and driven sheaves are in 
alignment and that shafts are parallel.

3

Fit internal key 

D

 between sheave and shaft and lock 

setscrew

A

 securely in place.

Adjusting:

1

Loosen setscrews 

B

 and 

C

 in moving parts of sheave and 

pull out external key 

E

. (This key projects a small amount 

to provide a grip for removing.)

2

To adjust sheave pitch diameter for desired speed, open 
moving parts by half or full turns from closed position. 

Do 

not open more than five full turns for 

A

 belts or six full 

turns for 

B

 belts.

3

Replace external key 

E

 and securely tighten setscrews 

B

over key and setscrews 

C

 into keyway in fixed half of the 

sheave.

4

Put on belts and adjust belt tension. 

Do not force belts 

over grooves

. See “Fan Drive Belt Adjustment” on page 

24.

5

Make future adjustments by loosening the belt tension and 
increasing or decreasing the pitch diameter of the sheave by 
half or full turns as required. Readjust belt tension before 
starting drive.

6

To provide the same pitch diameter, adjust both halves of 
the two-groove sheaves by the same number of turns from 
closed position.

7

Verify that all keys are in place and that all se screws are 
tight before starting drive. Check setscrews and belt tension 
after 24 hours service.

Figure 32: VP type sheave adjustment

LVP Variable Speed Sheaves

Mounting:

1

Slide sheave on motor shaft so that the side of the sheave 
with setscrew 

A

 is next to the motor when setscrew 

A

 is in 

the hub or barrel of the sheave.

2

When setscrew 

A

 is at an angle in the center flange 

B

,

mount it away from the motor so that the outer locking ring 
and flange can be removed to get to the setscrew.

3

To remove the flange and locking ring:

a

Loosen setscrews 

D

.

b

Loosen but 

do not remove

 capscrews 

E

.

c

Remove key 

F

.

Note: 

This key projects a small amount to provide a grip 

for removing.

d

Rotate the flange counterclockwise until it disengages 
the threads on the sheave barrel.

4

Verify that the driving and driven sheaves are in alignment 
and the shafts are parallel. When aligning two-groove 
sheaves, allow room between the sheave and motor to 
access capscrews 

E

.

5

Insert key 

C

 between the sheave and the shaft and tighten 

setscrew

A

 securely.

6

If flange and locking ring have been removed, when 
replacing them make sure that the inner and outer flanges 
are open from the closed position by the same amount as 

Fan rpm = motor rpm ×

Measured diameter at motor sheave
Measured diameter at fan sheave 

Two Groove

C

A

B

B

D

E

C

A

B

E

D

C

Single Groove

Key

E

 projects

to provide a grip
for removal.

Do not operate
sheeves with flange
projecting beyond
the hub end.

Содержание Skyline IM 777-1

Страница 1: ...McQuay IM 782 1 1 Installation and Maintenance Manual IM 777 1 Group Applied Air Part Number IM 777 Date June 2005 2005 McQuay International Skyline Air Handler Sizes 003 090...

Страница 2: ...ater Cooling Coils 8 Direct Expansion Coils 8 Steam Coils see Figure 18 on page 10 9 Water Heating Coils 11 Drain Pan Traps 11 Internal Isolation Assembly Adjustment 12 Electrical Installation 13 Oper...

Страница 3: ...fore unit installation to verify this has not happened 4 Screws bolts etc for assembling sections are supplied in a bag attached to each section All necessary gasketing is applied in the factory for s...

Страница 4: ...igure 2 Figure 1 Servicing space requirements Figure 2 Service clearance for electrical power devices Rigging Skyline air handlers ship as separate sections completely assembled or in modules of assem...

Страница 5: ...all assembly joints of the unit Before joining the sections apply at least 1 4 inch diameter bead of sealant to the mating faces of the cabinet Use the splice joint as a guide for applying the sealan...

Страница 6: ...slip the splice cap over the top panel flanges Bend the ends of the splice cap down to secure in place 6 Assemble the small splice plate at the top rail to secure the sections together at the top Use...

Страница 7: ...the jam nuts Figure 10 Opening fan section door Injected Foam Insulated Panels Skyline air handlers now are furnished with double wall injected foam insulated panels Foam panels are stronger more rig...

Страница 8: ...ctions are necessary See Figure 12 Figure 12 Discharge plenum If the unit has a top mixing box or economizer damper or a top duct connection field fabricate and install flashing to divert moisture fro...

Страница 9: ...same actuator if the dampers are the same size If the dampers are different sizes they must be driven by separate actuators and controlled appropriately Exhaust dampers are always driven by a separate...

Страница 10: ...e coils to freezing temperatures Water supply water return drain and vent connections extend through the end panel of the coil section All connections are labeled on the end panel Water supply and wat...

Страница 11: ...Use thermostatic traps only for air venting Use bucket traps for on off control only Locate traps at least 12 inches below the coil return connection Multiple coil installation Individually trap each...

Страница 12: ...aker 1 2 check valve Steam main Return main 12 min Vacuum breaker 1 2 check valve Steam main Return main 12 min Full size of return conn Check Valve Strainer Gate Valve Control valve modulating two po...

Страница 13: ...n pan trap to allow condensate to drain freely On both blow through and draw through units the trap depth and the distance between the trap outlet and the drain pan outlet must be twice the static pre...

Страница 14: ...he cap screw when adjustments are completed For models 040 through 090 the isolators should be at equal height during fan operation 6 Center the fan outlet in the outlet panel opening If adjustment is...

Страница 15: ...m of the fan motor junction box See Figure 22 Figure 22 Electrical conduit location CAUTION The base section of each cabinet has a drip pan installed below every panel that drains to the outside frame...

Страница 16: ...t m me la mort L alimentation lectrique du moteur du ventilateur de m me que la mise la terre du ch ssis du moteur doivent tre faits conform ment aux codes d nstallations lectriques en vigueur WARNING...

Страница 17: ...wheel s axially as needed and retightening setscrews 3 To obtain dimension B loosen screw and washer fasteners around periphery of funnel s shifting funnel radially as required and re torquing fastene...

Страница 18: ...5 440 24 5 500 27 560 30 620 33 750 36 5 810 40 25 880 44 5 940 49 1 000 54 25 1 060 60 1 120 Overlap Table 5 Wheel to inlet funnel relationship inline fans Wheel funnel overlap Size Overlap 150 375 1...

Страница 19: ...1 56 24 00 Maximum rpm Class I 3000 3000 2300 2000 1700 1500 Maximum rpm Class Il 4335 3918 3457 2858 2427 2255 300 250 200 150 100 90 80 Torque in lb 350 400 450 500 600 650 700 750 800 850 1000 1500...

Страница 20: ...00 AF30 00 500 600 700 800 2000 1000 1500 1500 2000 3000 2500 Torque in lb Table 9 Operating limits plenum fans Fan operating limits Plenum fans Diameter 13 5 15 16 5 18 25 20 22 25 24 5 27 30 33 36...

Страница 21: ...ble pitch sheaves Axial and radial runout of flanges uneven groove spacing out of balance Also similar faults in driven sheave b Bad V belts lumpy or mismatched belt tension too tight or too loose 4 B...

Страница 22: ...the air balance replace the variable pitched motor sheave with a properly sized fixed sheave A matching fixed sheave provides longer belt and bearing life and minimizes vibration Initially it is best...

Страница 23: ...number of turns from closed position 7 Verify that all keys are in place and that all se screws are tight before starting drive Check setscrews and belt tension after 24 hours service Figure 32 VP typ...

Страница 24: ...t on page 24 9 Before starting the drive ensure that all keys are in place and all setscrews and all capscrews are tight Check and retighten all screws and retension belts after approximately 24 hours...

Страница 25: ...hs L less than dia Seating torque Seating torque Seating torque Seating torque Length L Seating torque in lbs in lbs in lbs in lbs in lbs in lbs in lbs 1 4 20NC 150 12 5 100 87 7 3 3 16 50 5 16 11NC 3...

Страница 26: ...oving belt and fan can cause severe personal injury or death During installation and filter maintenance Verify that the belt and fan guards on plenum fan units are always in place Lock and tag out fan...

Страница 27: ...Filter gauge Table 15 Belt deflection force per Browning specifications Cross section Sheave diameter in Deflection force lbs Smallest sheave diameter range rpm range Cross section A B 5V Cross secti...

Страница 28: ...reezing of coils Removing and Replacing Components See Access Doors and Panels on page 5 for instructions on removing panels and opening fan access doors to remove or replace components Removing the F...

Страница 29: ...s See Figure 39 5 If this is an additional coil being installed and not a replacement locate the coil supply and return connections dimensionally Carefully drill holes in the end panels of the unit 6...

Страница 30: ...and remove the brass plugs for the vents and drains located in the connections 2 To access bolts holding the coils in place remove the panels on both the connection and opposite connection end of the...

Страница 31: ...must be prepaid The return of the part does not constitute an order for replacement Therefore a purchase order must be entered through the nearest McQuay representative The order should include part...

Страница 32: ...30 McQuay IM 777 1...

Страница 33: ...McQuay IM 777 1 31...

Страница 34: ...32 McQuay IM 777 1...

Страница 35: ......

Страница 36: ...ipment its care should be a high priority For training information on all McQuay HVAC products please visit us at www mcquay com and click on training or call 540 248 9646 and ask for the Training Dep...

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