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McQuay IM 777-3

31

Service and Maintenance

Removing Stacked Coils

Note: 

Top and bottom stacked coils are held together with 
steel plate and screws on one side and drain trough and 
screws on the other side. Remove the plate and trough 
before removing the coils. The coils cannot be removed 
attached together.

1

Disconnect all piping and remove the brass plugs for the 
vents and drains located in the connections. 

2

Remove all screws and remove the access panel.

3

Remove the bolts holding the coil in place and then lift and 
pull out the coil from the side.

4

Remove the steel plate and the drain trough that holds the 
coils together.

5

Remove the bolts on both ends of the top coil holding it in 
place and then lift and slide the coil out.

6

Remove the bolts on both ends of the bottom coil holding it 
in place and then lift and slide the coil out.

Installing Stacked Coils

1

Slide the bottom coil through the opening in the coil section 
onto the bottom coil rests. 

2

Place the coil up against the coil bulkheads to prevent any 
air bypass around the coil. 

3

Once the coil is in place, bolt the coil to the section.

4

Caulk the mounting surface of the steel plate and install the 
plate on the coils.

5

Caulk the mounting surface of the drain trough and install 
the drain trough on the coils.

6

Caulk the seams between the coil casings and blockoffs

.

7

Connect all piping and install the brass plugs for the vents 
and drains located in the connections. 

8

Install the access panel.

Removing and Installing Staggered Coils

Staggered coils have two banks of coils positioned a few 
inches apart in the direction of airflow. Both coils are secured 
to the unit on the connection and opposite connection end of 
the unit.

1

Disconnect all piping 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 coil section. 

3

Each coil is held in place with bolts located in the corners 
of the coil side plates. Remove the bolts and then lift and 
pull the coil out the side.

4

The bottom coil is fastened to the air block off plate. 
Remove the screws attaching this plate to the coil. 

5

Once the fasteners holding the coil in place are removed, 
pull out the coil from either side of the unit.

6

Install the coils in reverse order of removal.

Summary of Contents for IM 777-3

Page 1: ...Installation and Maintenance Manual IM 777 3 Skyline Air Handler Group Applied Air Sizes 003 090 Part Number IM 777 Date October 2008 2008 McQuay International...

Page 2: ...and Coils 10 Drain Pan Traps 13 Internal Isolation Assembly Adjustment 14 Electrical Installation 15 Operation Guidelines 16 Startup Checks 16 Fan Wheel Alignment 17 Operating Limits 19 Fan Vibration...

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

Page 4: ...12 deep See Figure 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 mo...

Page 5: ...1 Caulk 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 th...

Page 6: ...hannels when the unit sections are joined Touch up any places where gaps are noted 5 After sections are seated tightly together slip the splice cap over the top panel flanges Bend the ends of the spli...

Page 7: ...most section types and are provided based on customer request Fan Section Doors Note Opening fan section doors requires using a 1 2 socket wrench which satisfies ANSI standards and other codes that r...

Page 8: ...ccur If larger heavier components require mounting on unit panels use through bolts with flat washers through both outer and inner panels To maintain panel integrity seal both ends with an industrial...

Page 9: ...er Between Hoods Mounting Actuators The installing contractor is responsible for the mounting of all field installed actuators No provisions are made for the location of these actuators due to the num...

Page 10: ...s always use a backup pipe wrench Support pipework independently of the coils Water Cooling Coils Note Use glycol in water coils for outdoor air handlers Power failures and other mechanical issues can...

Page 11: ...se 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 c...

Page 12: ...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 position Float and thermostatic tr...

Page 13: ...drain 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...

Page 14: ...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 required lo...

Page 15: ...vicing Perform lockout tagout procedures to ensure that power can not be energized For variable frequency drives or other energy storing components that have been furnished and mounted by either McQua...

Page 16: ...couper la tension WARNING Fire electric shock hazard Can cause property damage personal injury or death Wire fan power supply and ground motor frame in accordance with local electric codes AVERTISSEM...

Page 17: ...s axially as needed and retightening setscrews Figure 26 Wheel to Inlet Funnel Relationship Plenum Fans Table 2 Wheel to Inlet Funnel Relationship Airfoil Type Airfoil Unit sizes 003 to 035 Unit size...

Page 18: ...line Fans Wheel funnel overlap Size Overlap 150 375 165 438 182 562 200 625 222 688 245 750 270 812 300 875 330 1 000 365 1 125 402 1 250 445 1 375 Overlap Table 6 Bearing Collar and Wheel Hub Set Scr...

Page 19: ...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...

Page 20: ...ameter 13 5 15 16 5 18 25 20 22 25 24 5 27 30 33 36 5 40 25 44 50 49 54 25 60 Maximum rpm Class I 2895 2589 2376 2256 2077 1875 1691 1479 1328 1209 1073 972 882 799 725 651 Maximum rpm Class II 3786 3...

Page 21: ...t or debris on wheel blades b Loose set screws in wheel hub or bearing to shaft c Wheel distorted from overspeed 2 Bent shaft 3 Drive faulty a Variable pitch sheaves Axial and radial runout of flanges...

Page 22: ...CAUTION Bearing overheating potential Can damage the equipment Do not overlubricate bearings Use only a high grade mineral grease with a 200 F safe operating temperature See below for specific recomme...

Page 23: ...ynthetic Lithium 2 Chevron Altiplex Synthetic 60 to 450 F 51 to 232 C Synthetic Lithium 2 Exxon ronex MP 40 to 300 F 40 to 149 C Mineral oil Lithium 2 Table 15 Recommended Fan Relubrication Grease Cha...

Page 24: ...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 F...

Page 25: ...ews E 9 Put on belts and adjust belt tension Do not force belts over grooves See Fan Drive Belt Adjustment on page 27 10 Before starting the drive ensure that all keys are in place and all setscrews a...

Page 26: ...s or 6 turns for the B belts Do not open C sheaves more than 9 1 2 turns Do not open 5V sheaves more than 6 turns Do not open 8V sheaves more than 8 turns 6 Tighten BOTH locking screws A in the outer...

Page 27: ...o N o t R e m o v e I n n e r L o c k i n g R i n g O u t e r L o c k i n g R i n g S p l i t T a p e r B u s h i n g 3 H o l e s f o r S p a n n e r W r e n c h o r D r i f t Belt span Deflection Bel...

Page 28: ...Filter Gauge Table 17 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...

Page 29: ...ls Removing and Replacing Components See Access Doors and Panels on page 7 for instructions on removing panels and opening fan access doors to remove or replace components Removing the Fan Section The...

Page 30: ...in place with a clamp See Figure 41 1 Disconnect all piping and remove the brass plugs for the vents and drains located in the connections 2 Remove all screws and remove the access panel 3 Remove the...

Page 31: ...ce bolt the coil to the section 4 Caulk the mounting surface of the steel plate and install the plate on the coils 5 Caulk the mounting surface of the drain trough and install the drain trough on the...

Page 32: ...arges 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...

Page 33: ...n spring mounted fan isolators Yes No N A E With power off do fans turn freely by hand Yes No N A F Electrical service corresponds to unit nameplate Yes No N A Volts __________ Hertz __________ Phase...

Page 34: ...eat wheel VFD model _____________________ serial _____________________ N A D Check for air bypass around heat wheel Yes No N A Yes No N A Yes No N A Signature _________________________________________...

Page 35: ...binet have any air leakage Yes No N A Location on unit ___________________________________________________________________________ 5 Were there any refrigerant leaks Yes No N A Shipping Workmanship De...

Page 36: ...training or call 540 248 9646 and ask for the Training Department Warranty All McQuay equipment is sold pursuant to its standard terms and conditions of sale including Limited Product Warranty Consul...

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