The system design and installation must follow accepted industry
practice as described in the ASHRAE Handbook, the National
Electric Code, and other applicable standards. Install this
equipment in accordance with regulations of authorities having
jurisdiction and all applicable codes.
Installation and maintenance must be performed by qualified
personnel familiar with applicable codes and regulations and
experienced with this type of equipment. Sheet metal parts,
self-tapping screws, fins, clips, and such items inherently have
sharp edges; the installer should exercise caution.
CAUTION
Sharp edges and coil surfaces are a potential injury hazard.
Avoid contact with them.
ATTENTION
Les bords tranchants et les surfaces des bobines sont un
risque de blessure. Ne les touchez pas.
Receiving and Handling
1 Carefully check items against the bills of lading to verify
all crates and cartons have been received. Carefully inspect
all units for shipping damage. Report damage immediately
to the carrier and file a claim.
2 Skyline air handler units are constructed of galvanized or
painted steel and are inspected thoroughly before leaving
the factory. Take care during installation to prevent damage
to units.
3 Take special care when handling the blower section. All
fans are dynamically balanced before leaving the factory.
Rough handling can cause misalignment or a damaged
bearings or shaft. Carefully inspect fans and shaft before
unit 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-section mounting. Units
require caulk sealant between sections.
Unit Storage
Store unit on a level surface. If air handling units are stored for
any period of time, periodically rotate the fan wheel to prevent
permanent distortion of drive components. In addition, grease
may settle in the lower part of the bearing, which can lead to
oxidation on the upper portion of the bearing surface. Keep the
fan bearings lubricated.
C = Standard unit cross section
M = Custom size cross section
Motor Location
A = Motor along side of fan housing
D = Motor downstream of belt drive plenum fan
F = Motor on inline fan
G = Motor downstream of direct drive plenum fan
T = Motor behind twin housed fans
Unit Type/Coil Position
B = Blow-thru cooling coil location
D = Draw-thru cooling coil location
H = Heating only
V = Vent only
McQuay IM 777-23
Installation Guidelines
Installation Guidelines
Service Clearances
In addition to providing adequate space around the unit for
piping coils and drains, access to at least one side of the unit is
always required to allow for regular service and routine
maintenance, which includes filter replacement, drain pan
inspection and cleaning, fan bearing lubrication, and belt
adjustment. Provide sufficient space—at least equal to the
length of the coil—on the side of the unit for coil removal. See
Figure 1 for servicing space requirements.
Maintain at least 54" of clearance in front of electrical power
devices. Electrical power devices that are mounted on the side
of the unit typically are up to 12" deep. See Figure 2.
Figure 1: Servicing Space Requirements
4 . 0 0 " b a s e r a i l e x t e n s i o n
W i d t h
3 0 . 0 0 "
4 . 0 0 "
W i d t h o f c o i l s e c t i o n
W i d t h o f
f a n s e c t i o n
Figure 2: Service Clearance for Electrical Power Devices
1 2 "
5 4 "
Rigging
Skyline air
assembled, or in modules of assembled sections.
be rigged as it ships from the factory. Do not rig units after
assembly.
rail
and
in the corners of each shipping section.
the unit cabinetry, use spreader bars. Position spreader bars to
prevent cables from rubbing the frame or panels. Before
hoisting into position, test lift for stability and balance. Avoid
twisting or uneven lifting of unit.
handlers ship as separate sections, completely
The unit must
Units are
provided with a factory-installed base
can be lifted using the 2" diameter lifting holes located
To prevent damage to
3 0 . 0 0 "
H e i g h t
Figure 3: Unit and Section Rigging
4McQuay IM 777-2
Installation Guidelines
Sta
Curb Mounting and Unit Leveling
Do not place a Skyline unit over an open curb unless it is
equipped with a curb-ready base. Installation instructions for
mounting units on a roof curb are provided in IM 770. For a
copy, contact your local McQuay representative or visit
www.mcquay.com. Make provisions under the unit to divert
any moisture from entering the building below.
For units without roof curb mounting, place the equipment
on a flat and level surface. Where surface irregularities
exist, shim the base of the unit at one or more points along
the length of the rails to prevent distortion or sagging of
the support rails. Uneven or distorted sections cause misfit
or binding of the doors and panels and improper draining
of drain pans. See Figure 4.
Figure 4: Leveling the Unit
h i m s e c t i o n s u n t i l
h e y a r e s t r a i g h t
n d l e v e l
S h i m t o p r e v e n t
d i s t o r t i o n i f w i d t h
i s o v e r 1 0 8 "
Assembling Sections
If the unit is shipped in more than one shipping section, rig
each section into position separately. Shipping sections are
provided with a connection splice joint attached on the leaving
air side of the shipping sectionsection that seals against the
frame channel on the entering-air side of the adjoining. The
splice joint is insulated and provides an air-tight seal between
two sections once they are assembled together. Align the splice
joint to seat into the mating gasket to provide an air seal. If the
splice joint was bent during shipping or rigging, restore it to its
original position. See Figure 8.
To assemble shipping sections:
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 the sealant. See Figure 5.
Figure 5: Apply Sealant to Mating Faces
1 / 4 " d i a m e t e r
b e a d c e n t e r e d
i n f a c e o f
c l e a r a n c e
U s e S p l i c e
J o i n t a s a
g u i d e
2
Pull sections together to fasten. Use straps and a ratchet to
help pull the sections together securely. Apply sealant to
any gaps that may admit moisture.
3 Fasten base rails together first using the 3/8"-16 × 5" bolts
located in the splice kit provided with the unit. See
Figure 7.
a To fasten two shipping sections together, four bolts are
needed (two on each side of the unit). The bolts are run
from one base rail into the other and fastened with a nut.
Complete each section bottom and top before attaching
additional sections.
b If desired, shipping sections for non curb-ready units
can be fastened together internally. To fasten internally,
run field-provided #10 sheet metal screws or drill
screws (4" long, maximum) through the interior frame
channel of one unit into the splice joint of the
neighboring section.
c Handle units with curb-ready bases and vestibules so the
lifting bracket can be removed after the unit is placed on
the curbing.
– Remove the lifting bracket that projects inward over
the curbing. Save the self tapping screws.
– When the adjacent section is placed in position, use
self tapping screw to secure the bases together.
McQuay IM 777-25
Installation Guidelines
Figure 6: Remove Vestibule Lifting Bracket
R e m o v a b l e
L i f t i n g B r a c k e t
Figure 7: Fasten Bottom of Section
Figure 8: Internal Fastening
A
S p l i c e C o l l a r
m u s t b e a l i g n e d
t o s e a l t o g a s k e t .
4 Check that the sealant is compressed between the mating
channels 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 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 5/16" bolts. See Figure 9.
3 / 8 x 1 " B o l t a n d N u t
Handle units with curb-ready bases and vestibules so the
d
lifting bracket can be removed after the unit is placed on
the curbing.
– Remove the lifting bracket that projects inward over
the curbing. Save the self tapping screws.
– When the adjacent section is placed in position, use
self tapping screw to secure the bases together.
Figure 9: Splice Cap and Splice Plate
S l i d e S p l i c e C a p o n
a n d b e n d e n d s d o w n
5 / 1 6 - 1 8 B o l t
5 / 1 6 - 1 8 N u t
S p l i c e
P l a t e
Panels, Frame Channels, and Doors
Panel Removal
To remove a side or top panel, remove the flat head Torx 30
fasteners along the sides of the panel. Lift off the panel after
removing all fasteners.
Frame Channel Removal
Frame channels that run the length of the unit along the top can
be removed to allow access to both the side and top of the unit.
To remove the frame channel, first remove the side panel(s).
6McQuay IM 777-2
Installation Guidelines
Once the side panel is off, remove the flat head Torx 30
fasteners in the corner of the frame channels. Then pull the
frame channel out the side. Remove any panel screws that are
within one inch of the of the frame since they are engaged into
the gasketed flange of the frame. See Figure 10.
Figure 10: Removing Panel Screws
Remove any
panel screws that
engage frame
Remove panel
to remove frame
ATTENTION
Les bords tranchants et les surfaces des bobines sont un
risque de blessure. Ne les touchez pas.
CAUTION
DO NOT attempt to rotate the cup. Damage to the unit will
occur.
ATTENTION
NE PAS tenter de faire tourner la cuvette (cup). Ceci va
dendomagger l’unité.
2 Insert 1/2" socket into cup and rotate 1/4 turn clockwise as
shown in Figure 11. If the cup and handle are on the left
side of the door, rotate 1/4 turn counterclockwise.
3 Rotate the door handle 1/4 turn clockwise and then 1/4 turn
counterclockwise to release any internal pressure or
vacuum and open the door. If the cup and handle are on the
left side of the door, rotate the door handle 1/4 turn
counterclockwise and then 1/4 turn clockwise.
4 To prevent air leakage, tighten the door panels by adjusting
the jam nuts.
Access Doors and Panels
For routine maintenance, access normally is obtained through
access doors or by removing side panels. Removing all flat
head fasteners along the sides of a panel allow it to be
removed.
Fan and filter sections are always provided with a service door
on one side of the unit. If requested on order, doors can be
provided on both sides of the unit. Optional service doors are
available for 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 require the “use of tools” to access compartments
containing moving parts or electrical wiring. See
Figure 11.
1 Remove padlock if one is present.
Figure 11: Opening Fan Section Door
Do Not Rotate Cup
Jam
Nuts
View from inside door
OPEN
CAUTION
Sharp edges and coil surfaces are a potential injury hazard.
Avoid contact with them.
McQuay IM 777-27
Installation Guidelines
Injected-Foam Insulated Panels
Skyline air handlers now are furnished with double-wall,
injected-foam insulated panels. Foam panels are stronger,
more rigid, and lighter than panels with fiberglass insulation.
The insulation R-value is improved to 13. However, foam
insulation can burn when exposed to flame or other ignition
sources and release toxic fumes. Take care in cutting and
sealing all field-cut openings in these panels.
Panel Cutting Procedure
1 Determine the number and location of holes required for
electrical conduit, piping, and control wiring as follows:
• Check that adequate space is available inside the unit for
conduit or pipe routing.
• Do not locate holes in a panel that provides access to key
maintenance components such as filters and fan
assemblies.
• Do not locate where the conduit or piping blocks airflow
or obstructs hinged access doors.
2 Once a proper location is determined, drill a small pilot
hole completely through the panel. Then use a sharp hole
saw or a saber saw and cut from each side of the panel.
3 Seal the double-wall panel on each side with an industrial/
commercial grade silicone sealant or duct seal compound.
It is extremely important to seal each panel hole or
penetration securely so it is airtight, watertight, and so that
there is no exposed insulation.
WARNING
Flame and smoke can cause equipment
damage, severe personal injury, or
death.
Before operating unit, seal all piping and
wiring holes on both inner and outer panels
with an industrial grade silicone sealant or
duct seal compound. Do not use a cutting
torch or expose panel to fire. Panel
damage can occur.
WARNING
La fumée et les flammes peuvent
endommager le matériel et causesr des
blessures graves ou la mort.
Avant d’utiliser le dispositif, obturer tous les
trous de passage de tubulures et de fils
ménagés dans les panneaux intérieurs et
extérieurs au moyen d’une pâte à base de
silicone ou d’un mastic d’étanchéite â
conduits de qualité industrielle.
Ne pas se servir d’un chalumeau
coupeur ni exposer les pannequx à une
flamme nue pour ne pas risquer de les
endommager.
Prop 65—Substances in fuel or from fuel combustion can cause personal injury or death,
and are known to the State of California to cause cancer, birth defects or other reproductive harm.
sealant or duct seal compound
Field Mounting Junction Boxes and
Other Components
For field mounting 4" × 4" or smaller junction boxes to the
standard panel exterior, use a minimum quantity of 4, 3/16"
diameter pop rivets. Do not use self-tapping drill screws.
They will not tighten nor secure properly and panel
damage 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 industrial/commercial grade silicone sealant or duct seal
compound.
The unit frame channel is another excellent location for
securing heavier components; self-tapping screws are not
acceptable. Ensure that the location permits the full operation
of all access doors and panels and does not interfere with other
vital components.
Duct Connections
Use flexible connectors on the outlet and inlet duct
connections of all units. Do not position down flow fans over
air ducts that are routed down intothe building. Use a
discharge plenum when bottom connections are necessary. See
Figure 13.
Figure 13: Discharge Plenum
D i s c h a r g e
P l e n u m
8McQuay IM 777-2
Installation Guidelines
If the unit has a top mixing box or economizer damper or a top
duct connection, field fabricate and install flashing to divert
moisture from the connection. The flashing must lap over the
standing seams of the top panels. The flashing also must lap
over the side edges of the unit. See Figure 14.
Figure 14: Flashing Over Top Panels and Sides of Units
F l a s h i n g
D u c t
F l a s h i n g
Duct
F l a s h i n g
U n i t t o p
p a n e l
F l a s h i n g
When units are ordered with exhaust hoods and intake hoods
adjacent to each other, install a field-supplied barrier to
prevent recirculation of exhaust air into the intake openings.
See Figure 16.
Figure 16: Field-Installed Barrier Between Hoods
I n t a k e
B a r r i e r
E x h a u s t
Mounting Actuators
Dampers and Hoods
Side dampers may be provided in the mixing box and
economizer sections of units. When dampers are provided, a
removable panel is located above the weather hood to provide
access to the damper drive shaft. Other access may be available
depending on the specific construction of the unit. See Figure 15.
Figure 15: Filler Panel Over the Weather Hood
Remove screws
and panel to access
damper control shaft.
Hood
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 number of options and
arrangements available and the variety of specific applications.
Typically, actuators are mounted inside the cabinet. Provide
proper support for the actuator to avoid excessive stress in the
cabinet, linkage, or damper shafts.
Note – Damper blades are at full flow when open to 70 degrees.
Do not open blades further than 70 degrees.
Fresh air and return air dampers can be linked together and
driven from the 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 actuator.
A typical rotary electric actuator can handle up to 40 sq. ft. of
damper. For pneumatic actuators, allow 5 in-lb per square foot
of damper area.
McQuay IM 777-29
Installation Guidelines
Seal holes
cut for piping
Seal holes
cut for piping
CAUTION
Maximum damper rotation is 70°. Maximum shaft torque is 205
inches/pound. Greater rotation or torque can cause equipment
damage.
ATTENTION
La rotation maximale des volets est de 70°. Le couple (torque)
maximum de l’arbre est de 205po/lb. Une plus grande rotation
(ou torque) peut endommager l’équipement.
Face and Bypass Section Mounting
Figure 18: Seal Holes for Piping—Standard Base Rail Units
Internal and external face and bypass sections are mounted
together using the instructions for horizontal components and
do not require additional instruction. Skyline air handlers are
provided with a bypass duct that is integral to the unit
construction and requires no field assembly.
Face and bypass dampers may or may not be linked together.
When dampers are placed before a single bank of coils, they
always are linked together and require a single actuator. When
dampers bypass a stacked or staggered coil, the dampers are
not linked and require multiple actuators.
Face and bypass dampers have a torque requirement of
10 in-lbs per square foot of damper face area.
Piping Vestibules
For units that include a piping vestibule, cut the openings for
routing the field piping as required in the field. Carefully seal
passages cut through the panels to prevent air leakage. A
single metal thickness pan is provided in the bottom of the
curb-mounted vestibule. The pan can be removed if necessary.
If holes are cut into the pan for a piping passage, seal the holes
to prevent moisture leakage. See Figure 17.
Figure 17: Seal Holes for Piping—Curb Mounted Units
Piping and Coils
When designing and installing piping:
• Follow applicable piping design, sizing, and installation
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 independently of the coils.
Water Cooling Coils
Note – Use glycol in water coils for outdoor air handlers. Power
failures and other mechanical issues can expose 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 water return connections are typically
male NPT iron pipe.
• When installing couplings, do not apply undue stress to the
connection extending through unit panel. Use a backup
pipe wrench to avoid breaking the weld between coil
connection and header.
• Follow recommendations of the control manufacturer
regarding types, sizing, and installation of controls.
Direct Expansion Coils
• The coil distributor and suction connection extend through
the end panel of the coil section.
• Check nozzle in distributor for proper tonnage.
• When a (field supplied) thermostatic expansion valve is
located outside the unit and connected directly to the
distributor (except on units with piping vestibules). Do not
apply heat to the body of the expansion valve.
• The thermostatic expansion valve must be the external
equalizer tube type. Connect the 1/4-inch diameter external
For units with standard base rails, the vestibule is open to the
coil section; therefore, seal all holes to prevent air leakage.
10McQuay IM 777-2
equalizer tube provided on the coil to the connection on the
expansion valve.
•
Use care when piping the system, making sure all joints are
tight and all lines are dry and free of foreign material. For
typical refrigerant piping, see condensing unit product manual.
Steam Coils (see Figure 19 on page 12)
Piping
•
Steam supply and steam return connections typically are male
NPT iron pipe and are labeled on the end panel of coil section.
Connections extend through the coil section end panel.
• When installing couplings, do not apply undue stress to the
connection extending through unit panel. Use a backup
pipe wrench to avoid breaking the weld between coil
connection and header.
• Support piping independently of coils and provide adequate
piping flexibility. Stresses resulting from expansion of
closely coupled piping can cause serious damage.
• Do not reduce pipe size at the coil return connection. Carry
return connection size through the dirt pocket, making the
reduction at the branch leading to the trap.
Coils
• Pitch all steam coils in units toward the return connection.
• Do not drip supply mains through the coil.
• Do not attempt to lift condensate when using modulating or
on/off control.
•
Install vacuum breakers on all applications to prevent
retaining condensate in the coil. Generally, connect the
vacuum breaker between the coil inlet and the return main.
The vacuum breaker should be open to the atmosphere and
the trap design should allow venting of large quantities of air.
Traps
Note – Do not place steam traps outdoors.
• Size traps in accordance with the manufacturers’
recommendations. Make sure the required pressure
differential is always available. Do not undersize.
• Use float and thermostatic or bucket traps for low pressure
steam. On high pressure steam, use bucket traps. Use
thermostatic traps only for air venting.
• Use bucket traps for on/off control only.
Installation Guidelines
•
Locate traps at least 12 inches below the coil return connection.
• Multiple coil installation.
– Individually trap each coil or group of coils that is
controlled individually trapped.
– Coils in series—use separate traps for each coil, or a bank
of coils.
– Coils in parallel—a single trap can be used, but an
individual trap for each coil is preferred.
– Do not attempt to lift condensate when using modulating
or on/off control.
• With coils arranged for series airflow, use a separate control
on each bank or coil in the direction of airflow.
Valves
• Do not use modulating steam valves on high pressure
systems.
• Properly size modulating valves. Do not undersize.
• Freezing conditions (entering air temperatures below 35°F).
– McQuay strongly recommends 5JA, 8JA, 5RA and 8RA
coils.
– Supply 5 psi steam to coils at all times.
• Do not use modulating valves. Provide control by face and
bypass dampers.
– Consider using two or three coils in series with two
position steam control valves on the coil or coils that
handle 35°F or colder air. Use a modulating valve on the
downstream coil to provide the desired degree of control.
– Thoroughly mix fresh air and return air before it enters the
coil. Also, to obtain true air mixture temperatures,
properly locate temperature control elements.
– As additional protection against freeze-up, install the trap
sufficiently below the coil to provide an adequate
hydrostatic head to remove condensate during an
interruption in the steam pressure. Estimate three feet for
each 1 psi of trap differential required.
– On startup, admit steam to coil ten minutes before
admitting outdoor air.
– Close fresh air dampers if steam supply pressure falls
below the minimum specified.
McQuay IM 777-211
Installation Guidelines
Figure 19: Piping Arrangements
Float and
thermostatic trap
Vacuum breaker
1/2" check valve
1/4" petcock
for continuous
air venting
1"
min.
12" min.
5GA or 8GA coils. Note that the
addition of a vacuum breaker to
permit the coil to drain during
shutdown.
Check ValveStrainerGate Valve
High Pressure (over 25 psi)
Steam main
Return main
1/4" petcock
for continuous
High pressure
float or bucket
trap
Return main
air venting
High pressure
bucket trap
5TA, 8TA, or 5HA coils. Condensate is lifted to overhead return
main
Low Pressure (to 25 psi)
Vacuum breaker
1/2" check valve
1" min.
Control valve
modulating
two position
12" min.
Full size of
return conn.
Steam main
5J, 5G, 8J or 8G coils.
Steam main
Vacuum breaker
1/2" check valve
Return main
Vacuum breaker
1/2" check valve
12" min.
Full size of
return conn.
Steam main
12" min.
5JA or 8JA coil. Installed in series.
Note that each coil must have a
separate control valve and trap.
Return main
Steam main
Vacuum breaker
1/2" check valve
Return main
5RA, 8RA, or 5SA coils. Banked two
high, individual trapping of each coil as
shown is preferred.
5RA, 8RA, or 5SA coils. Installed
12McQuay IM 777-2
Installation Guidelines
Water Heating Coils
CAUTION
Improper installation, use, or maintenance of water
heating coils can cause equipment damage. Read and
follow instructions carefully.
ATTENTION
Si l’installation, l’utilisation ou l’entretien des serpentins
de chauffage à eau sont inadéquats, ceci endommagera
l’équipement. Lire et suivre attentivement les instructions.
• Water supply and water return connections extend through
the end panel of the coil section. All connections are labeled
on the end panel.
• Water supply and water return connections are male NPT
iron pipe.
• When installing couplings, do not apply undue stress to the
connection extending through unit panel. Use a backup pipe
wrench to avoid breaking the weld between the coil
connection and header.
• Follow recommendations of the control manufacturer
regarding types, sizes, and installation of controls.
• Do not use hot water coils with entering air below 40°F.
• If fresh air and return air are to be heated by a hot water coil,
carefully design the system to provide thorough mixing
before air enters the coil.
• To prepare coils for winter operation, see “Winterizing
Water Coils” on page 28.
Figure 20: Allow Adequate Distance Between Trap Outlet
and Drain Pan Outlet
Pressure (P)
at the drain pan
2P
2P
Note – The door panels on some applications have a close
clearance over the drain pipes. Extend the drain fitting
with a coupling if necessary for door clearance. See
Figure 21.
– Use material that can withstand freezing temperatures for
outdoor drain traps.
– Drain traps that dry out can allow cold air to seep into the
equipment.
Figure 21: Extend Drain Fitting for Door Clearance
C l e a r a n c e
Drain Pan Traps
Run drain lines and traps full size from the drain pan
connection. Install 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 pressure in the drain pan
section under normal operation so the trap remains sealed. See
Figure 20.
D r a i n
McQuay IM 777-213
Installation Guidelines
r
Internal Isolation Assembly Adjustment
On units with internally isolated fan and motor assemblies, the
Figure 22: Removing Shipping Brackets
Unit sizes 006 - 090
assemblies are secured for shipment. with a tie-down at each
point of isolation.
Before Operating the Unit:
Remove the shipping brackets and tie-down bolts (see
Figure 22) and discard. The shipping brackets located on the
opposite drive side of the unit are difficult to access from the
drive side of the unit. Either remove them before the unit is
assembled, or remove the panel on the opposite drive side to
gain access.
The spring isolators under the four corners of the fan and
motor assembly are factory adjusted while the fan was not
running. See Table 1 below. With the unit operating at normal
cfm and static pressure, all the isolators should be at the same
S h i p p i n g b r a c k e t
e m o v e a n d d i s c a r d
( T y p i c a l 4 p l a c e s )
S h i p p i n g h o l d d o w n
r e m o v e a n d d i s c a r d
( T y p i c a l 4 p l a c e s )
S e e d e t a i l " A "
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
height opening. If adjustments are required, loosen the 1/2"
cap screw on top of the isolator and turn the adjusting bolt to
D i m " H "
lower or raise the fan and motor base. Retighten the cap screw
when adjustments are completed.
Table 1: Spring Mount Adjustments
Spring mount adjustment at rest
Fan discharge positionTop or bottom horz. (dim "H")
Unit sizes 003–035
13.75
24.25
34.25
43.75
Unit sizes 040–-090
16.00
26.50
36.50
46.00
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
P O S 3
P O S 4
S h i p p i n g
b r a c k e t
M o t o r
F a n
F a n i s o l a t o r p o s i t i o n n u m b e r s
P O S 2
A i r f l o w
P O S 1
S h i p p i n g h o l d
d o w n s c r e w
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, loosen the cap
D e t a i l A
screw on top of the isolator assembly. Turn the adjustment nut
below the fan frame to lower or raise the fan motor and frame
assembly. Retighten the cap screw on top of the isolator
assembly.
14McQuay IM 777-2
Installation Guidelines
Electrical Installation
Wiring
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. Assurezvous 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.
Figure 23: Electrical Conduit Location
Fan Motor
Junction Box
Conduit Entrance
(typical)
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.
ATTENTION
Utiliser du fil de cuivre seulement. La non utilisation de fil de
cuivre peut causer des dommages à l’équipement.
• 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.
• 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.
McQuay IM 777-215
Operation Guidelines
Operation Guidelines
Startup Checks
When performing startup and service, always take thorough
safety precautions. Only trained, experienced personnel should
perform these functions.
WARNING
Rotating fan. Can cause severe injury or death. Before
servicing fans, lockout and tag out power.
ATTENTION
Risques de dommages dans le moteur du ventilateur
électrique. Si Ia température de l’air a proximité du
ventilateurest élevée, le moteurdu ventilateur électrique peut
chauffer et brûler. Sur les transmetteurs d’air à circulation
transversale ou les transmetteurs dont le ventilateur est en
aval de l’unité de chauffage, régler la température de l’air
sortant de l’unité de chauffage à 40°C (104°F).
AVERTISSEMENT
Ventilateur en rotation. Peut causer des blessures sévères
ou même la mort. Avant d’effectuer l’entretien des ventilateurs,
bloquer et 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.
AVERTISSEMENT
Risques d´incendie et d’électrocution pouvant causer des
dommages matériels, des blessures et même la mort.
L’alimentation électrique du moteur du ventilateur de même
que la mise à la terre du chàssis du moteur doivent être faits
conformément aux codes d’installations électriques en
vigueur.
WARNING
Fan motor requires overload protection. Failure to provide
motor overload protection can result in fire, property damage,
electric shock, personal injury, or death. Connect motor to an
overload protective device rated in compliance with local
electric codes.
AVERTISSEMENT
Risques d’incendie et d’électrocution pouvant causer des
dommages matériels, des blessures et même la mort.
Connecter au moteur du ventilateur électrique un dispositif de
protection contre les surcharges conforme aux codes
d’installations électriques en vigueur.
CAUTION
Do not overheat fan motor. High air temperatures in the fan
section can cause the fan motor to burnout. On draw-through
air handlers or air handlers with the fan section down the air
stream from the heating section, the discharge air temperature
of the heating section must not exceed 104°F (40°C).
Before Starting the Unit:
Before entering fan section, make sure that fan electrical
power source is disconnected and locked in the OFF position.
1 Check that the unit is completely and properly installed
with ductwork connected.
2 Check that construction debris is removed/filters are clean.
3 Check that all electrical work is complete and properly
terminated.
4 Check that all electrical connections are tight and that the
proper voltage is connected. Phase imbalance must not
exceed 2%.
5 Check that ball bearings on the fan shaft and motor are
prelubricated and do not need grease before startup.
6 Check tightness of setscrews in bearings and fan wheel(s).
If retightening is needed, position the fan wheel(s) per
Table 2 or Table 3 on page 17. Torque set screws per
Table 6 on page 18.
CAUTION
Equipment damage due to loose fasteners represents
improper start-up and equipment abuse. It is not covered by
the warranty.
ADVERTISSEMENT
Les dommages dus à des attaches installées de façon
inappropriée représentent un démarrage inadéquat et un
abus d’équipement. Ceci n’est pas couvert par la garantie.
7 Check alignment of fan and motor sheaves and belt tension.
Adjust if necessary. Check tightness of sheave setscrews
and/or capscrews. See Figure 36 and Figure 37 on page 26.
8 Leak test the thermal system to verify that connections are
tight.
9 Check that the condensate drain is trapped.
10 Rotate the shaft by hand to be sure it is free.
Fan Startup:
Start and run fan. Observe the rotation. If the fan operates
backward, reverse two legs of the three-phase motor
connections.
16McQuay IM 777-2
Operation Guidelines
O
Note – Variable pitch fan drives usually are provided for
operation in the mid-speed adjustment range. However,
the drives usually ship with the adjustment opened up for
minimum fan speed. Adjust the drives for the proper
airflow. See “Fan Drive Adjustments” on page 22.
After the First 48 Hours of Operation:
1 Disconnect and lock electrical power source.
2 Check tightness of all bearing, wheel, and sheave setscrews
(or capscrews). See Table 6.
3
Recheck belt tension and adjust if necessary. Belts that are
tensioned sufficiently to slip one to two seconds at startup
perform satisfactorily, extending life and reducing vibration. If
retensioning is necessary, be certain to retain sheave
alignment.
Fan Wheel Alignment
Figure 24: Wheel-to-Inlet Tunnel Relationship—Airfoil Type
Fan Wheels (Housed)
E q u a l s p a c i n g
B
a l l a r o u n d
A
A
Table 3: Wheel-to-Inlet Funnel Relationship—Forward
Curved Type Fan Wheels
Forward curved
Unit sizes 003 to 035Unit sizes 040 to 090
Diameter (in)
9 x 40.256.3520 (Class 1 & 2)0.246.10
9 x 70.133.30 22.38 (Class 1 & 2) 0.41 10.41
9 x 90.256.3525 (Class 1 & 2)0.47 11.94
Table 6: Bearing Collar and Wheel Hub Set Screw Torque
set screwMinimum torque
Diameter (in)ft/lbskg/m.
1/45.5.76
1/1610.51.45
3/819.02.63
7/1629.04.01
1/242.05.81
5/892.012.72
18McQuay IM 777-2
Operation Guidelines
Operating Limits
Do not exceed the operating limits in Table 7. A fan wheel
operated beyond the rpm and temperature limits shown can
suffer permanent distortion or fracture. The resulting
unbalance can cause severe unit vibration.
Table 7: Unit Sizes 003 to 035
Fan operating limits
Forward curved—housed
Diameter 9 × 49 × 79 × 910.6212.6215182022.2524.50
Maximum rpm Class IN/A2189222319341614132811551050944858
Maximum rpm Class Il224428542896251820911725145012001030910
Airfoil—housed
Diameter13.2214.5616.1919.6921.5624.00
Maximum rpm Class I300030002300200017001500
Maximum rpm Class Il433539183457285824272255
Figure 28: Torque for FC Variable Inlet Vanes (in–lb)Figure 29: Torque for AF Variable Inlet Vanes (in–lb)
500
400
350
300
250
200
150
Torque (in–lb)
100
90
80
200
250
300
350
Fan speed (rpm)
400
FC36.00
500
450
FC33.00
FC30.25
FC27.62
550
600
650
FC25.00
750
700
800
FC22.38
850
900
1000
FC20.00
1500
450
400
350
300
250
200
150
100
90
80
70
Torque (in–lb)
60
50
40
35
30
750
800
850
900
1000
AF24.00
AF21.56
1500
Fan speed (rpm)
2000
AF19.69
AF16.19
2500
AF14.56
AF13.22
3000
3500
4000
4500
Table 8: Unit Sizes 040 to 090
Fan operating limits
Forward curved—housed
Diameter2022.382527.6230.253336
Maximum rpm Class I1010930790690650600560
Maximum rpm Class Il128111781011910835763715
Airfoil—housed
Diameter2022.2524.527303336.5
Maximum rpm Class I2077187516911479132812091073
Maximum rpm Class Il2703241321991928173015791401
McQuay IM 777-219
Operation Guidelines
Figure 30: Torque for FC Variable Inlet Vanes (in–lb)
300
250
FC24.50
800
850
FC22.25
900
1000
FC20.00
FC18.00
FC15.00
FC12.62
1500
200
150
100
90
Torque (in–lb)
80
70
60
50
350
400
450
500
600
650
700
550
Fan speed (rpm)
750
2000
Figure 31: Torque for AF Variable Inlet Vanes (in–lb)
2000
1500
1000
900
800
700
600
500
400
350
300
Torque (in–lb)
250
200
150
100
550
600
650
700
750
800
850
AF40.25
900
1000
Fan speed (rpm)
AF38.50
AF33.00
1500
AF30.00
AF27.00
AF24.50
AF22.25
2000
AF20.00
2500
Table 9: Operating Limits—Plenum Fans
Fan operating limits
Plenum fans
Diameter13.51516.5 18.252022.25 24.527303336.5 40.25 44.504954.2560
Maximum rpm Class I28952589 2376 2256 2077 18751691 1479 1328 12091073972882799725651
Maximum rpm Class II3786 3384 3100 2959 27032413 2199 1928 1730 15791401 1264 1150 1043938847
Maximum rpm Class III4000 40003887 3735 3409 3065 27802423 2182 1984 1756 15981447 1314 1178 1071
Maximum rpm Class I2727248822362041183516651476133012081072973880
Maximum rpm Class II340931112796255122942082184616621510134012161100
Twin fans
Diameter9 x 910.6212.621518.1220
Maximum rpm 257524002000170014001200
Maximum HP101515304040
20McQuay IM 777-2
Operation Guidelines
Figure 32: Torque Requirements at 100% WOV for
SWSI Plenum Fans with NESTED Inlet Vane
5000
4000
3000
2000
1000
Torque (lb./in.)
900
Torque (in-lb)
800
700
600
500
400
300
200
100
600
200
300
400
700
500
Fan Speed (rpm)
800
900
1000
0
0
6
2
4
5
0
9
4
5
4
4
2
0
4
5
6
3
0
3
3
0
0
3
1500
Fan Vibration Levels
Each unit as shipped is trim balanced to operate smoothly. To
provide satisfactory operation after shipping and installation,
use the accepted industry guidelines for field balancing fans.
See Table 11.
Table 11: Vibration Levels
Fan speed (rpm)Vibration
800 or less5 mils maximum displacement
801 or greater0.20 in/sec. maximum velocity
Note: Excessive vibration from any cause contributes to premature fan and
motor bearing failure. Monitor overall vibration levels every six months
of operation. An increase in levels is an indication of potential trouble.
Vibration Causes
1 Wheel imbalance
a Dirt or debris on wheel blades
b Loose set screws in wheel hub or bearing-to-shaft
0
7
2
5
4
2
2000
3000
c Wheel distorted from overspeed
2 Bent shaft
3 Drive faulty
a Variable 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 Bad bearings, loose bearing hold-down bolts
5 Motor imbalance
6 Fan section not supported evenly on foundation
McQuay IM 777-221
Service and Maintenance
Service and Maintenance
Periodic Service and Maintenance
1 Check all moving parts for wear every six months.
2 Check bearing collar, sheave, and wheel hub setscrews,
sheave capscrews, and bearing hold-down bolts for
tightness every six months.
3 Annually check and snug all electrical connections. Inspect
for signs of water damage such as corrosion and repair if
necessary. Check ground conductor and connection
integrity. Service if needed.
Ball Bearing Lubrication
1 Motor bearings—All ball bearings are prelubricated and do
not require additional grease at time of installation.
However, periodic cleaning out and renewal of grease is
necessary. Exercise extreme care to prevent foreign matter
from entering the bearing. It also is important to avoid over
greasing. Use a high grade, clean mineral grease with the
following characteristics:
• Melting point over 302°F (150°C)
• Free from oil and soap separation under operating and
storage conditions
• Free of abrasive matter, acid, alkali and moisture
Specific greasing instructions are located on a label
attached to the fan section door.
2 Fan shaft bearings—All ball bearings are prelubricated and
do not require addition of grease at time of installation.
However, periodic renewal of grease is necessary. Bearings
are accessible through access door in fan section. Grease
fittings are located in front of door opening on drive end of
blower section. Apply grease slowly until a very slight
bleeding of grease from the seals is noted. Tie hinged
door(s) open. Do not over lubricate. Wipe off any excess
grease to prevent overheating.
The lubrication interval varies with the period of operation
and temperature of the ambient air. Use the guidelines in
the table below.
Table 12: Lubrication Guidelines
Bearing operating temp range
Temperature
Continuous operation6 months4 months2 months
12-hr. day operation12 months12 months6 months
to 130°F
(54°C)
to 150°F
(66°C)
over 150°F
(66°C)
Table 13: Lubricants Recommended for Fan Shaft Ball
Bearings
ManufacturerProduct name
Texaco Lubricants Company Premium RB–30 to 300 –34 to 149
Keystone Ind. Lubricants 81EP-2 0 to 250
Mobil Oil Corporation Mobilith SCH100
Chevron U.S.A. Inc. SRI-2
Exxon Company, U.S.A. Ronex MP
Shell Oil Company Alvania No. 2
Note: Temperature ranges over 225°F are shown for lubricants only. High
temperature applications are not suitable for standard air handler
components.
Tem p . rang e
°F°C
–
18 to 121
–
40 to 350–40 to 177
–
20 to 325–29 to 163
–
40 to 300–40 to 149
–
20 to 240–29 to 116
Fan Drive Adjustments
WARNING
Before servicing fans, lock out and tag out all power to the
unit. Fans or belts can cause severe personal injury or death.
AVERTISSEMENT
Avant de faire le service sur les ventilateurs,couper et
indiquer que le courant est coupé. Les ventilateurs ou les
courroies peuvent causer des blessures personnelles graves
ou entraîner la mort.
WARNING
Do not open the hinged access door and screw-fastened
access panels while the unit is operating.
strong suction forces can cause severe personal injury or death.
AVERTISSEMENT
Ne pas ouvrir les portes d’accès à charnières et les
panneaux à vis lorsque l’unité fonctionne. Les pièces
mobiles et le niveau de succion peuvent causer des blessures
personnelles graves ou même entraîner la mort.
Upon completion of 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 to have a variable
pitched motor sheave for the purpose of air balancing. Once
the balance is achieved, fixed sheaves maintain balancing and
alignment more effectively. Replace the adjustable sheaves
with fixed sheaves.
Moving parts and
With the electrical power disconnected, locked and tagged out,
measure the diameter of the V-belt outer surface where it
passes around the sheave (pitch diameter). Calculate fan speed
from the motor nameplate rpm.
Fan rpm = motor rpm ×
22McQuay IM 777-2
Measured diameter at motor sheave
Measured diameter at fan sheave
Service and Maintenance
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
turns for
3 Replace external key E and securely tighten setscrews B
over key and setscrews
B belts.
C into keyway in fixed half of the
A belts or six full
sheave.
4 Put on belts and adjust belt tension. Do not force belts
over grooves. See “Fan Drive Belt Adjustment” on page
26.
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 33: VP Type Sheave Adjustment
A
Single Groove
Key E projects
to provide a grip
for removal.
B
A
Two Groove
C
B
E
D
Do not operate
C
sheeves with flange
projecting beyond
the hub end.
B
D
C
E
McQuay IM 777-223
Service and Maintenance
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
5 Insert key C between the sheave and the shaft and tighten
setscrew
6 If flange and locking ring have been removed, when
A securely.
E.
replacing them make sure that the inner and outer flanges
are open from the closed position by the same amount as
the other flange. Determine this by accurately measuring
the top width of the grooves.
7 Insert key F.
8 Tighten setscrews D and capscrews E.
9 Put on belts and adjust belt tension. Do not force belts
over grooves. See
26
.
“Fan Drive Belt Adjustment” on page
10 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 of service.
Adjusting
1 Slack off belt tension if belts have been installed.
2 Loosen setscrews D.
3 Loosen but do not remove capscrews E.
4 Remove key F.
Note: This key projects a small amount to provide a grip
for removing.
5 Adjust pitch diameter by opening or closing the movable
flanges by half or full turns.
Note: Two-groove sheaves are supplied with both grooves
set at the same pitch diameter.
To provide the same pitch diameter for satisfactory
operation, move both movable flanges the same number of
turns. Do not open sheaves more than five turns for
or six turns for
6 Replace key F.
7 Tighten setscrews D and capscrews E.
8 If belts have been installed, readjust belt tension. If belts
B belts.
A belts
have not been installed, install them and adjust belt tension.
Do not force belts over grooves. See “Fan Drive Belt
Adjustment” on page 26.
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 of operation.
Figure 34: LVP Type Sheave Adjustment
A
A
E
C
F
D
E
D
B
E
C
A
F
D
A
Section A-ASection A-A
24McQuay IM 777-2
Service and Maintenance
MVP Variable Speed Sheaves
Mounting:
1 Verify both driving and driven sheaves are in alignment and
the shafts are parallel. The centerline of the driving sheave
must be in line with the centerline of the driven sheave. See
Figure 35.
2 Verify that all setscrews are torqued to the values shown in
Table 14 before starting drive. Check setscrew torque and
belt tension after 24 hours of service.
Adjusting:
1 Adjust motor base forward to release belt tension. Remove
the belts for easier adjustment.
2 Loosen, but do not remove both of the locking setscrews A
in the outer locking ring by using a hex key or torque
wrench with a hex bit.
3 Adjust sheave to desired pitch diameter by turning the outer
locking ring. Use a spanner wrench or drift inserted into the
three holes that are located 120° apart on the ring.
4 Any pitch diameter can be obtained within the sheave
range. One complete turn of the outer locking ring changes
the pitch diameter 0.233".
5 Do not open sheaves more than the following:
• Do not open B sheaves more than 4 3/4 turns for the A
belts 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 locking ring
before operating the drive. Use a torque wrench and tighten
to the value shown in Table 14.
7
Replace belts and adjust the motor base to tension the belts
properly. See “Fan Drive Belt Adjustment” on page 26.
8 Do not loosen any screws other than the two locking screws
A in the outer locking ring when adjusting the sheave pitch.
Do not operate the drive until the locking screws have been
set to the torque specifications.
Lengths equal or greater than dia.For lengths (L)) less than dia.
Hollow head set screws only
Figure 35: Sheave Adjustment
Must be
parallel
Bearing
Motor
Must be
parallel
Center lines
must coincide
Adjustable
Sheave
McQuay IM 777-225
Service and Maintenance
Figure 36: Sheave Adjustment
A d j u s t a b l e
C e n t e r - F l a n g e
S p l i t T a p e r
B u s h i n g
F i x e d
C e n t e r - F l a n g e
( 2 ) L o c k i n g
S e t s c r e w s " A "
F l a t h e a d S o c k e t S c r e w s
( D o N o t R e m o v e )
C a p s c r e w s
( D o N o t R e m o v e )
Fan Drive Belt Adjustment
General Rules of Tensioning
1 The ideal tension is the lowest tension at which the belt
does not slip under peak load conditions.
2 Check tension frequently during the first 24 to 48 hours of
operation.
3 Over tensioning shortens belt and bearing life.
4 Keep belts free from foreign material that can cause
slippage.
5 Inspect V-drive on a periodic basis. Adjust tension if the
belt is slipping. Do not apply belt dressing. This can
damage the belt and cause early failure.
Tension Measurement Procedure
1 Measure the belt span. See Figure 37.
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 by 64. Determine the force applied while
in this position.
3 Compare this force to the values in Table 15.
Figure 37: Drive Belt Adjustment
Deflection =
B
Belt span
64
e
l
t
s
p
a
n
S t a t i o n a r y
E n d - F l a n g e
O u t e r
L o c k i n g - R i n g
I n n e r L o c k i n g - R 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
WARNING
Moving 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 fans to prevent accidental start up.
• Do not enter the filter compartment until the fan is
completely stopped.
• Use approved equipment for reaching filters located above
normal reach. Do not step on filter frames or unit
components.
• Floor surfaces must be dry and free of oil or grease.
WARNING
Pendant l’installation et où l’entretien des filtres, une
courroie en mouvement ou un ventilateur en opération
peuvent causer des blessures graves où même causer la
mort.
• S’assurer que les gardes de courroie et de ventilateur sont
toujours en place.
• Verouiller les démarreurs des ventilateurs et afficher un
avis de mise-en-garde afin de prévenir tout accident ou
démarrage.
• Attendre que le ventilateur soit complètement arrêté avant
d’entrer dans l’unité.
• Utiliser seulement des équipements approuvé pour joindre
les bancs de filtres; ne pas mettre soit sur les cadres des
filtres ou même sur toutes composantes de l’unité.
• La surface des planchers doit être sec et libre de toute
trace d'huile et où de graisse.
26McQuay IM 777-2
Table 15: Belt Deflection Force (per Browning® specifications)
Sheave diameter (in)Deflection force (lbs)
Cross
section
A, AX
B, BX
5V, 5VX
Smallest
sheave
diameter range
3.0 to 3.6
3.8 to 4.8
5.0 to 7.0
3.4 to 4.2
4.4 to 5.6
5.8 to 8.6
4.4-6.7
7.1-10.9
11.8 -1 6.0
rpm
range
1000 to 25003.75.54.16.1
2501 to 40002.84.23.45.0
100 to 25004.56.85.07.4
2501 to 40003.85.74.36.4
1000 to 25005.48.05.79.4
2501 to 40004.77.05.17.6
850 to 25004.97.2
2501 to 40004.26.2
860 to 25005.37.97.110.5
2501 to 40004.56.77.19.1
860 to 25006.39.48.512.6
250 to -40006.08.97.310.9
Front loaded filter options require that the filters be removed
and replaced from inside the unit.
To remove filters, rotate the wire clips. This releases both the
prefilter and the final filter. When installing clean filters, check
to verify the filters are fully seated in the frame. See Figure 38.
Figure 38: Frame and Filters with Holding Clips
F i n a l
F i l t e r
F i l t e r
P r e f i l t e r
R o t a t e
W i r e C l i p s
F r a m e
Filter Gauges
Filter gauges indicate pressure drop for installed filters.
Table 16 shows the typical filter pressure drop for clean filters
at rated air flow. The tables also show a final pressure drop for
front loaded filters.
Where a single filter gauge is used, the prefilters can be
removed to check the pressure drop of the final filters.
EfficiencyN/A
Rated velocity (fpm)500
Initial pressure drop.25
Final pressure drop1.0
Pleated 62 Plus filters
Size2"4"
Efficiency70%70%
Initial pressure drop.42.37
Final pressure drop1.01.0
Maintaining the Coil
1 The coil must be clean to obtain maximum performance.
Check once a year under normal operating conditions and,
if dirty, brush or vacuum clean. Use a chemical coil cleaner
on multiple row coils. Read and follow the chemical
cleaner’s instructions as some cleaners may contain harsh
chemicals. Take care not to damage fins while cleaning.
2 Drain pans in any air 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 pan
to overflow. Also, keep the drain pans clean to prevent the
spread of disease. Cleaning should be performed by
qualified personnel.
3 Dirt and lint can clog the condensate drain, especially with
dirty filters. Inspect twice a year to help avoid overflow.
Winterizing Water Coils
Coils can freeze due to air stratification or failure of outdoor
air dampers and/or preheat controls. Do not depend on routine
draining of water cooling coils for winter shutdown as
insurance against freeze-up. Severe coil damage can result.
Drain all coils as thoroughly as possible and then treat in the
following manner.
• Fill each coil independently with an antifreeze solution
using a small circulating pump and again thoroughly drain.
• Check freezing point of antifreeze before proceeding to next
coil. Due to a small amount of water always remaining in
each coil, there is a diluting effect. The small amount of
antifreeze solution remaining in the coil must always be
concentrated enough to prevent freeze-up.
Note – Carefully read instructions for mixing antifreeze solution
used. Some products have a higher freezing point in their
natural state when mixed with water. McQuay
International is not responsible for the freezing of
coils.
WARNING
Mold can cause personal injury. Clean drain pan regularly
so mold does not develop.
AVERTISSEMENT
La moisissure présente un danger respiratoire. Pour éviter
la moisissure, nettoyer régulièrement le bassin de drainage.
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.
WARNING
Before removing any component, lock out and tag out all
power to the unit. Fans and belts can cause severe personal
injury or death.
AVERTISSEMENT
Avant d’enlever toute composante, couper et indiquer que
l’alimentation électrique à l’unité est coupée. Les
ventilateurs et les courroies peuvent entraîner des blessures
personelles graves ou même la mort.
Removing the Fan Section
The fan shaft, motor, and any drive components can be
removed and replaced through the access door opening. If
required, the side panel can be removed for additional access.
If fan replacement is required, the entire fan assembly can be
pulled out the side of the cabinet. The fan assembly includes
the fan housing, the bearing support, and the fan base.
28McQuay IM 777-2
Service and Maintenance
Removing the Fan Assembly
1 Remove the side panels and any intermediate supports
(follow instructions for side panel removal).
2 Once the panels and any intermediate supports are
removed, disconnect the neoprene bulk head seal that is
attached to the fan discharge.
3 Remove the four discharge angles 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 sled is out, loosen the fan bearings and pull
out the shaft.
6 Disconnect the fan housing from the fan sled, and bearing
support by removing the attaching bolts.
7 Replace the new fan, reconnect the shaft and bearings and
put the fan assembly in the cabinet.
8 Replace panels and fasteners.
Removing and Replacing the Coil
Removing Single Coils
Note – Single coils are bolted to the unit on the connection end.
The connection end is held 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 screws holding the coil in place.
4 Lift and pull the coil out the side.
Figure 40: Single Coil Top Installation/Removal
Opposite
connection
end
Coil
Connection
end
Coil
Installing Single Coils
1 Slide the coil through the opening in the coil section onto
the bottom coil rests.
2 To prevent any air bypass around the coil, place coils up
against the coil bulkheads. See Figure 41.
3 Once the coil is in place, fasten the coil to the section.
4 Caulk the seams between the coil casings and bulkheads.
See Figure 41.
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 Remove the brass plugs for the vents and drains on the
connections.
7 Slip the panel over the connections.
8 Replace the brass plugs and panel fasteners.
Figure 41: Single Coil Side Installation/Removal
Opposite connection end
Coil
Coil
Bulkhead
Connection end
Coil
Coil
Rests
McQuay IM 777-229
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
Slide the bottom coil through the opening in the coil section
1
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.
30McQuay IM 777-2
Warranty
Warranty
Consult your local McQuay Representative for warranty
details. Refer to Form 933-43285Y. To find your local
McQuay Representative, go to www.mcquay.com.
Warranty Return Material Procedure
Defective material may not be returned without permission of
authorized factory service personnel of McQuay International
in Minneapolis, Minnesota, (763) 553-5330. A “Return
Goods” tag must be included with the 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. Transportation charges 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 number, model number, and serial number of the
unit involved.
Credit will be issued on customer's purchase order following
an inspection of the return part and upon determination that the
failure is due to faulty material or workmanship during the
warranty period.
Replacement Parts
When writing to McQuay for service or replacement parts,
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 failure, along with an explanation of the
malfunctions and a description of the replacement parts
required.
McQuay IM 777-231
McQuay Training and Development
Now that you have made an investment in modern, efficient McQuay equipment, 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 Department.
Warranty
All McQuay equipment is sold pursuant to its standard terms and conditions of sale, including Limited Product
Warranty. Consult your local McQuay Representative for warranty details. Refer to Form 933-43285Y. To find your
local McQuay Representative, go to www.mcquay.com.
This document contains the most current product information as of this printing. For the most up-to-date product
information, please go to www.mcquay.com.