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McQuay IM 777-4

Electrical Installation

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 (

Figure 25

).

Figure 25: 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 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 Skyline OAC 003

Page 1: ...Installation and Maintenance Manual IM 777 4 Skyline Air Handler Group Applied Air Systems Part Number IM 777 Date May 2009 2009 McQuay International Models OAC OAH 003G 090G...

Page 2: ...Water Heating Coils 13 Drain Pan Traps 13 Internal Isolation Assembly Adjustment 14 Electrical Installation 16 Wiring 16 Operation Guidelines 17 Startup Checks 17 Before Starting the Unit 17 Fan Wheel...

Page 3: ...ion to verify this has not happened Note 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 sectio...

Page 4: ...be lifted using the 2 diameter lifting holes located in the corners of each shipping section To prevent damage to the unit cabinetry use spreader bars Position spreader bars to prevent cables from ru...

Page 5: ...ils together first using the 3 8 16 5 bolts located in the splice kit provided with the unit Figure 7 a To fasten two shipping sections together four bolts are needed two on each side of the unit The...

Page 6: ...channels when the unit sections are joined Touch up any places where gaps are noted 2 After sections are seated tightly together slip the splice cap over the top panel flanges Bend the ends of the sp...

Page 7: ...ost 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 req...

Page 8: ...can occur 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 indus...

Page 9: ...e location of these actuators due to the number of options and arrangements available and the variety of specific applications Typically actuators are mounted inside the cabinet Provide proper support...

Page 10: ...stallation information in ASHRAE handbooks Observe all local codes and industry standards Do not apply undue stress at the connection to coil headers always use a backup pipe wrench Support pipework i...

Page 11: ...bucket traps 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 individual...

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: ...ain 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 p...

Page 14: ...ghten the cap screw when adjustments are completed For models 040 through 090 the isolators should be at equal For models 040 through 090 the isolators should be at equal height during fan operation 6...

Page 15: ...s i t i o n n u m b e r s D i m H S p r i n g h e i g h t a d j u s t m e n t s c r e w S p r i n g h e i g h t a d j u s t m e n t s c r e w S h i p p i n g h o l d d o w n s c r e w S h i p p i n g...

Page 16: ...agout 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...

Page 17: ...perty damage personal injury or death Wire fan power supply and ground motor frame in accordance with local electric codes AVERTISSEMENT Risques d incendie et d lectrocution pouvant causer des dommage...

Page 18: ...C by loosening wheel hub setscrews shifting wheel s axially as needed and retightening setscrews Figure 28 Wheel to Inlet Funnel Relationship Plenum Fans Table 3 Wheel to Inlet Funnel Relationship Ai...

Page 19: ...10 5 1 45 3 8 19 0 2 63 7 16 29 0 4 01 1 2 42 0 5 81 5 8 92 0 12 72 Table 6 Wheel to Inlet Funnel Relationship Inline Fans Table 8 Unit Sizes 003 to 035 Fan operating limits Forward curved housed Dia...

Page 20: ...00 AF24 50 AF22 25 AF20 00 AF38 50 AF33 00 AF30 00 500 600 700 800 2000 1000 1500 1500 2000 3000 2500 Torque in lb Table 10 Operating Limits Plenum Fans Fan operating limits Plenum fans Diameter 13 5...

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: ...F safe operating temperature See below for specific recommended lubricants Table 13 Recommended Lubricants and Amounts for Fan Motor Bearings Mfr Grease NEMA Size Amount to Add oz Texaco Polystar or P...

Page 23: ...ning 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 a...

Page 24: ...D and capscrews E 9 Put on belts and adjust belt tension Do not force belts over grooves See Fan Drive Belt page 26 10 Before starting the drive ensure that all keys are in place and all setscrews an...

Page 25: ...the following a Do not open B sheaves more than 4 3 4 turns for the A belts or 6 turns for the B belts b Do not open C sheaves more than 9 1 2 turns c Do not open 5V sheaves more than 6 turns d Do not...

Page 26: ...2 Place belt tension checker squarely on one belt at the center of the belt span Apply force to the checker perpendicular to the belt span until the belt deflection equals belt span distance divided...

Page 27: ...endre que le ventilateur soit compl tement arr t avant d entrer dans l unit Utiliser seulement des quipements approuv pour joindre les bancs de filtres ne pas mettre soit sur les cadres des filtres ou...

Page 28: ...conditioning unit may have some moisture Algae etc can grow due to airborne spores and bacteria Periodic cleaning is necessary to prevent this buildup from plugging the drain and causing the drain pa...

Page 29: ...s that hold the neoprene canvas in place around the discharge opening 4 Disconnect the fan sled from each of the corner mounts and pull the entire assembly out the side of the unit 5 After the fan sle...

Page 30: ...il 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...

Page 31: ...s refer to the model number and serial number of the unit stamped on the serial plate attached to the unit If replacement parts are required mention the date of installation of the unit and date of fa...

Page 32: ...returned material Enter the required information to expedite handling and prompt issuance of credits All parts must be returned to the appropriate McQuay facility designated on the Return Goods tag Tr...

Page 33: ...ed all setscrews on pulleys bearings and fans Yes No N A D Have the hold down bolts been backed off on spring mounted fan isolators Yes No N A E With power off do fans turn freely by hand Yes No N A F...

Page 34: ...I HEAT RECOVERY A Heat wheel rotates freely Yes No N A B Heat wheel VFD operates properly Yes No N A C Heat wheel VFD model _____________________ serial _____________________ N A D Check for air bypas...

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: ...on 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 Con...

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