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McQuay IM 777-3

15

Installation Guidelines

Electrical Installation

Wiring

Electrical service to the fan must correspond to the rated 
voltage on the motor or electrical panel nameplate and 
conform to the National Electric Code and local restrictions.

Connect the fan section metal frame to the building 
electrical ground.

A door electrical interlock is not provided as standard.

Thermal motor protection is external to the unit.

Locate electrical conduit entrances for units above the bottom 
of the unit, high enough to clear components inside, but below 
the bottom of the fan motor junction box. See Figure 23.

Figure 23: Electrical Conduit Location

When the unit is provided with an external junction box and 
variable frequency drive (VFD), the VFD itself will be 
mounted on the drive side fan panel inside the fan cabinet.  
The external junction box will provide loose wire 
connection to the VFD and to the motor.  An external 
mounted keypad/display control box will be provided and 
connected to the VFD for manual adjustment of the VFD.  

When not being serviced, close and secure electrical panel 
doors to prevent accidental contact with live parts and 
prevent ingress of moisture and airborne contaminants.

Control wiring - Access to the VFD is through the fan 
cabinet access door.  Provide shielded cable only as 
described in the VFD manual provided with the unit.  Route 
wire through panel (see Page 6 for cutting and sealing 
procedure) so that it not interfere with any other components 
or in the way of any access doors.  Do not drill through drip 
or drain pans.  Refer to the VFD installation manual 
provided with the unit for detailed control wiring 
instructions.

DANGER

Capacitor hazardous voltage!

 Failure to disconnect power 

and discharge capacitors before servicing will result in serious 
injury or death.
Disconnect all electric power (including remote disconnects) 
before servicing. 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 McQuay, or by others, refer to the 
specific manufacturer’s literature for allowable waiting periods 
for discharge of capacitors. Verify capacitors have been 
discharged using an appropriate voltmeter.

ADVERTISSEMENT

Voltage de condesateur à risquee de danger!

 À défaut de 

débrancher la puissance électrique et de décharger le 
condensateur avant de faire le service, il peut en résulter des 
blessures sérieuses et même la mort.
Débranchez toute puissance électrique (incluant les 
sectionneurs à distance) avant de faire du service. Assurez-
vous de procéder au cadenassage et à la pose d’avis assurant 
que la puissance ne peut être rétablie . 
Pour le variateur de fréquence variable ou tout autre 
composante pouvant accumuler de l’énergie qui auraient été 
fournis et installés par McQuay ou autres, se référer à la 
littérature spécifique du manufacturier donnant les périodes 
spécifiques d’attente nécessaires pour la décharge du 
condensateur. Vérifier que le condensateur est totalement 
déchargé avec les voltmètres appropriés.

CAUTION

Use copper conductors only. 

Failure to use copper 

conductors can result in equipment damage.

ATTENTION

Utiliser du fil de cuivre seulement. 

La non utilisation de fil de 

cuivre peut causer des dommages à l’équipement.

CAUTION

The base section of each cabinet has a drip pan installed 
below every panel that drains to the outside frame trough. Any 
holes cut through the bottom of the unit must also penetrate 
the drip pan. If holes are cut in the drip pan, seal them to 
prevent moisture leakage.

ATTENTION

Chaque cabinet est muni d’une base avec une panne 
d’égouttement installée en-dessous de chaque panneau qui 
évacuera l’eau vers la gouttière extérieure. Tous les trous 
percés au bas de l’unité doivent pénétrer la panne 
d’égouttement. S’il y a des trous dans la panne 
d’égouttement, les sceller pour empêcher les fuites d’eau.

Conduit Entrance
(typical)

Fan Motor
Junction Box

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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